The first approach naturalists took to dealing with the great variety of animals was to sort them into groups, such as vertebrates (including fish, amphibians, reptiles, birds, and mammals) and arthropods (insects, crustaceans, arachnids, and more), but between and within these groups there are many differences. What makes a fish different from a salamander? Or an insect from a spider? On a finer scale, clearly a leopard is a cat, but what makes it different from a domestic tabby? And closer to home, what makes us different from our chimpanzee cousins?

The key to answering such questions is to realize that every animal form is the product of two processes--development from an egg and evolution from its ancestors. To understand the origins of the multitude of animal forms, we must understand these two processes and their intimate relationship to each other. Simply put, development is the process that transforms an egg into a growing embryo and eventually an adult form. The evolution of form occurs through changes in development.

Both processes are breathtaking. Consider that the development of an entire complex creature begins with a single cell--the fertilized egg. In a matter of just a day (a fly maggot), a few weeks (a mouse), or several months (ourselves), an egg grows into millions, billions, or, in the case of humans, perhaps 10 trillion cells formed into organs, tissues, and parts of the body. There are few, if any, phenomena in nature that inspire our wonder and awe as much as the transformation from egg to embryo to the complete animal. One of the great figures in all of biology, Darwin's close ally Thomas H. Huxley, remarked:

The student of Nature wonders the more and is astonished the less, the more conversant he becomes with her operations; but of all the perennial miracles she offers to his inspection, perhaps the most worthy of admiration is the development of a plant or of an animal from its embryo. -- Aphorisms and Reflections (1907)

The intimate connection between development and evolution has long been appreciated in biology. Both Darwin, in The Origin of Species (1859) and The Descent of Man (1871), and Huxley in his short masterpiece, Evidence as to Man's Place in Nature (1863), leaned heavily on the facts of embryology (as they were in the mid-nineteenth century) to connect man to the animal kingdom and for indisputable evidence of evolution. Darwin asked his reader to consider how slight changes, introduced at different points in the process and in different parts of the body, over the course of many thousands or a million generations, spanning perhaps tens of thousands to a few million years, can produce different forms that are adapted to different circumstances and that possess unique capabilities. That is evolution in a nutshell.

For Huxley, the nub of the argument was simple: we may marvel at the process of an egg becoming an adult, but we accept it as an everyday fact. It is merely then a lack of imagination to fail to grasp how changes in this process that are assimilated over long periods of time, far longer than the span of human experience, shape life's diversity. Evolution is as natural as development. [SNIP]

While Darwin and Huxley were right about development as key to evolution, for more than one hundred years after their chief works, virtually no progress was made in understanding the mysteries of development. The puzzle of how a simple egg gives rise to a complete individual stood as one of the most elusive questions in all of biology. Many thought that development was hopelessly complex and would involve entirely different explanations for different types of animals. So frustrating was the enterprise that the study of embryology, heredity, and evolution, once intertwined at the core of biological thought a century ago, fractured into separate fields as each sought to define its own principles.

Because embryology was stalled for so long, it played no part in the so-called Modern Synthesis of evolutionary thought that emerged in the 1930s and 1940s. In the decades after Darwin, biologists struggled to understand the mechanisms of evolution. At the time of The Origin of Species, the mechanism for the inheritance of traits was not known. Gregor Mendel's work was rediscovered decades later and genetics did not prosper until well into the 1900s. Different kinds of biologists were approaching evolution at dramatically different scales. Paleontology focused on the largest time scales, the fossil record, and the evolution of higher taxa. Systematists were concerned with the nature of species and the process of speciation. Geneticists generally studied variation in traits in just a few species. These disciplines were disconnected and sometimes hostile over which offered the most worthwhile insights into evolutionary biology. Harmony was gradually approached through an integration of evolutionary viewpoints at different levels. Julian Huxley's book Evolution: The Modern Synthesis (1942) signaled this union and the general acceptance of two main ideas. First, that gradual evolution can be explained by small genetic changes that produce variation which is acted upon by natural selection. Second, that evolution at higher taxonomic levels and of greater magnitude can be explained by these same gradual evolutionary processes sustained over longer periods.

The Modern Synthesis established much of the foundation for how evolutionary biology has been discussed and taught for the past sixty years. However, despite the monikers of "Modern" and "Synthesis," it was incomplete. At the time of its formulation and until recently, we could say that forms do change, and that natural selection is a force, but we could say nothing about how forms change, about the visible drama of evolution as depicted, for example, in the fossil record. The Synthesis treated embryology as a "black box" that somehow transformed genetic information into three-dimensional, functional animals.

The stalemate continued for several decades. Embryology was preoccupied with phenomena that could be studied by manipulating the eggs and embryos of a few species, and the evolutionary framework faded from embryology's view. Evolutionary biology was studying genetic variation in populations, ignorant of the relationship between genes and form. Perhaps even worse, the perception of evolutionary biology in some circles was that it had become relegated to dusty museums.

Such was the setting in the 1970s when voices for the reunion of embryology and evolutionary biology made themselves heard. Most notable was that of Stephen Jay Gould, whose book Ontogeny and Phylogeny revived discussion of the ways in which the modification of development may influence evolution. Gould had also stirred up evolutionary biology when, with Niles Eldredge, he took a fresh look at the patterns of the fossil record and forwarded the idea of punctuated equilibria--that evolution was marked by long periods of stasis (equilibria) interrupted by brief intervals of rapid change (punctuation). Gould's book and his many subsequent writings reexamined the "big picture" in evolutionary biology and underscored the major questions that remained unsolved. He planted seeds in more than a few impressionable young scientists, myself included.

To me, and others who had been weaned on the emerging successes of molecular biology in explaining how genes work, the situations in embryology and in evolutionary biology were both unsatisfying, but they presented enormous potential opportunities. Our lack of embryological knowledge seemed to turn much of the discussion in evolutionary biology about the evolution of form into futile exercises in speculation. How could we make progress on questions involving the evolution of form without a scientific understanding of how form is generated in the first place? Population genetics had succeeded in establishing the principle that evolution is due to changes in genes, but this was a principle without an example. No gene that affected the form and evolution of any animal had been characterized. New insights in evolution would require breakthroughs in embryology.

Today’s blog was an excerpt taken from the Introduction of Endless Forms Most Beautiful, (c. 2006), which was a finalist for both the Los Angeles Times Book Prize and the National Academy of Sciences Communication Award, as well as being a Discover magazine and USA Today “Top Science Books of the Year.” Learn more here.

In tomorrow’s blog, we move to the concluding chapter, where Sean Carroll summarizes some of the most exciting lessons learned from research in Evo Devo.

Editorial Policy: The editing for these excerpts involves removing the odd sentence or two—indicated by putting [SNIP] at the appropriate point(s)—and sometimes inserting annotations where warranted [also enclosed in square brackets] to provide background information.

So, I’ve decided to try a slightly different approach for the next while—one that has these sorts of folks in mind. From time to time, you can still expect those more in-depth, technical articles, or perhaps a discussion of some new research that makes the popular press, or even an analysis of some new argument from the IDM or RTB. These will be breaks from the new routine, however. For the most part, we’re going to stick to the basics, much like you would if you took an introductory evolution course at a university. Don’t worry, though: this course doesn’t have any prerequisites! All that’s needed is a willingness to learn.

What you can expect

The goal of this course is straightforward: to provide evangelical Christians with a step-by-step introduction to the science of evolutionary biology.  This will provide benefits beyond just the joy of learning more about God’s wonderful creation. An understanding of the basic science of evolution is of great benefit for reflecting on its theological implications, since this reflection can then be done from a scientifically-informed perspective. From time to time we might comment briefly on some issues of theological interest (and suggest resources for those looking to explore those issues further), but for the most part, we’re going to focus on the science. For folks interested in the interaction between science and Christianity, I heartily recommend Ted Davis’ recent series as a fabulous introduction to the topic.

You can also expect a slow, patient pace. Since this course is intended for folks with little or no background in biology, we’re going to take our time to make sure no one gets left behind. This might be frustrating to folks who already know a fair bit about evolution. Hopefully even more knowledgeable readers will learn some new and interesting details along the way—but the goal will primarily be to help folks who are less well versed in evolution increase their understanding.

You can also expect a survey of many different areas that have some bearing on evolution. We’ll examine geology, paleontology, biogeography, genetics, and a host of other topics in order to provide a “big picture” overview. This broad-brush approach means that any given individual post will not necessarily be “convincing” to folks who have doubts about evolution. Think about assembling a large jigsaw puzzle: placing any individual piece, on its own, doesn’t convincingly demonstrate what the overall picture will show. This course will be like that. Each topic we cover will put a few pieces in place here and there, slowly building towards the final overall picture.

Since evolution is an active science, this process will also highlight where there are “missing pieces” that are still being sought by scientists. All of this is well and good, since the purpose of this course is not so much to convince anyone of the validity of evolutionary theory, but rather to inform readers about the nature and scope of evolution as a scientific theory in the present day. My goal is to provide readers with a basic understanding of what evolution is and how it works. Given that as the primary goal, if one finds the scope of the evidence ultimately convincing (or not) is somewhat beside the point. The intent here is to provide readers with information they can use to make their own, informed decision.

How you can help

First and foremost, you can help by spreading the word about this series to folks you think would be interested in learning more about evolution in a non-threatening environment. Secondly, you can help me by asking questions in the comments. One of the challenges of being a specialist is having the ability to put oneself in the shoes of someone just starting out. What might seem obvious to me may not seem obvious to you, and I hope you’ll feel that no question is too basic or too simplistic. If you’re wondering about something, it’s almost guaranteed that other folks are, too! So, please don’t be shy. I’ll do my best to answer questions in the comments, though I hope that some of our more skilled commenters will (respectfully!) help out here, as well. Finally, you can help by letting me know what broader areas of evolution you find confusing. I have my own ideas about what areas of evolution are commonly misunderstood, but I’d love to hear from readers about what areas they find difficult to understand. I’ll use this input to shape the topics I will cover as we go forward.

Getting started

In the next post in this course, we’ll dive into the course content by introducing two key areas: how scientific theories work in general, and how evolution in particular works as the current organizing theory of modern biology. 

Good science has an addiction to theories,¹ and for science to be good science, it must deal with good scientific theories.  What constitutes a good scientific theory?  That is a very involved question, but a user’s view of good scientific theories looks something like this:

1.  A scientific theory is not a guess or suspicion.  For example, “I have a theory about who shot President Kennedy,” reflects the colloquial meaning of the word “theory,” and not the meaning conveyed by scientists when they use the word “theory.”  
2. Scientific theories are convincing explanatory frameworks that efficiently integrate a large body of evidence about the world.  Good scientific theories have the capacity to make sense of a wide range of data that made less sense before the introduction of the theory. 
3. In order to be called a scientific theory, it must have been successfully tested and re-tested many times.²
4. A scientific theory must be falsifiable in order to be truly scientific.  The theory has to live constantly at risk from new data.³ 
5. A theory must have predictive power.⁴  Good theories allow scientists to make predictions based on the theory that, when tested, turn out to be at least roughly correct. 

These are not the only characteristics of a scientific theory, but they probably represent the most important features for practitioners of science. 

If we hold contemporary evolutionary theory to these standards, how well does it do?  Since the inception of evolutionary theory by Charles Darwin in 1859 with the publication of On the Origin of Species, there are four characteristics of evolutionary theory that have endured 150 years of further research:

1. Living species are descendants of other species that lived in the past.
2. These past species lived in populations that underwent gradual transformation so that the individuals in these populations changed their appearance, behaviors, metabolisms, and life histories over long spans of time.⁵
3. New forms of life arose by means of a process called speciation in which one lineage splits into two distinct lineages.  This continual splitting of organismal lineages leads to a nested genealogy of species.  This nested genealogy forms a veritable tree of life, whose root represents the first species to arise and whose twigs represent the millions of species living today.  If you trace back any pair of twigs from the modern species you will find that their histories merge at some node on the tree where the two species share a common ancestor.⁶ 
4. This process of biological change that takes place throughout the advance of geologic time, or evolution, occurs by means of variation in organisms (which we know today is due to genetic mutations) that is acted on by either random genetic drift or natural selection. Those individuals with variations better suited to the current environment leave more offspring, thus changing the average appearance of the population over time and making it a better fit to the environment. This improving fit between organisms and their environment gives the appearance of organisms having been well designed for their milieu.⁷ 

What is the evidence for these aspects of evolutionary theory?  The evidence is actually immense, but I will restrict this discussion to just a few items. 

First there is the fossil record. If life results from a natural process such as biological evolution, then we should observe a progression of fossil organisms that proceed from relatively simple, single-celled organisms in the oldest rocks to more complex, multicellular organisms in younger rocks. When paleontologists examine the geologic column, they perceive that some of the oldest and deepest layers of the geologic column contain fossils of microorganisms, and then marine invertebrates in younger layers above those,⁸ and then much later and higher up in the geologic column fish appear, followed later and higher still by amphibians, and then by reptiles, mammals, and birds.⁹  Thus, the general presentation of the fossil record in the rock record comports exactly with what the theory of evolution predicts. 

However, the fossil story gets even better, because scientists can trace evolutionary trends throughout the fossil record.  For example, horses get bigger, fuse their leg bones and toes into a single bone with a thick hoof and grow the thickness of their tooth enamel;¹⁰ Cenozoic brachiopod shells get narrower, decrease their rib numbers and beak angle;¹¹ diatoms get bigger;¹² and primate fossils reduce the size of their teeth and expand the size of their brains.¹³ 

Additionally, Darwin predicted that there should be organisms preserved in the fossil record that possess features found in two different types of creatures. Such organisms are “transitional forms” that bridge the gap between different types of organisms.¹⁴ However, the fossil record of Darwin’s time provided little evidence of such transitional forms.¹⁵ Therefore, Darwin gambled that future paleontological research would provide sufficient evidence to corroborate his theory. How did this gamble turn out? Since Darwin’s time, paleontologists have discovered transitional fossils that are part fish and tetrapod,¹⁶ part amphibian and part reptile,¹⁷ part dinosaur and part bird,¹⁸ and part reptile and part mammal.¹⁹ Once again, we would predict such paleontological trends and the existence of such transitional fossils if life came about through a process of organic evolution. Clearly paleontological research since Darwin’s time has powerfully vindicated his theory. 

Please join us for part two of this post tomorrow, where we will discuss how signs of evolution can be detected in organisms living today, and how evidence from multifarious scientific fields—not just biology and paleontology—have bolstered the theory of evolution and added to our understanding of how natural selection works.

Notes

1. Ratzsch, Del. The Battle of Beginnings: Why Neither Side Is Winning the Creation-Evolution Debate. Downer’s Grove, WI: Intervarsity Press, 1996. pp. 104–119. 
2. Kitcher, Philip. Abusing Science: The Case Against Creationism. Cambridge, MA: MIT Press, 1983. pp. 45–54.
3. Ibid, 42–48.  .
4. Ratzsch, Del. Science and Its Limits: The Natural Sciences in Christian Perspective. Downer’s Grove, WI: Intervarsity Press, 2000. pp. 21–24. 
5. Hall, Brian K., and Benedikt Hallgrimsson. Strickberger’s Evolution. 5th ed. Burlington, MA: Jones and Bartlett, 2013. pp. 19–68. 
6. Kitcher, Philip. Living With Darwin: Evolution, Design, and the Future of Faith. New York: Oxford University Press, 2009. pp. 43–71. 
7. Futuyma, Douglas J. Evolution. 3rd ed. Sundbury, MA: Sinauer Associates, 2013. pp. 281–343. 
8. Valentine, James W. On the Origin of Phyla. Chicago: University of Chicago Press, 2006. pp. 429–464. 
9. Carroll, Robert L. Vertebrate Paleontology and Evolution. New York: W. H. Freeman and Company, 1990. 
10. MacFadden, “Horses, the Fossil Record, and Evolution,” 131–158; McFadden, Bruce J. “Fossil Horses from "Eohippus" (Hyracotherium) to Equus: Scaling, Cope's Law, and the Evolution of Body Size.” Paleobiology 12, no. 4 (1986): 355–69.; Prothero, Donald R., and R.M. Schoch, eds. The Evolution of Perissodactyls. New York: Clarendon Press, 1989. ; McFadden, Bruce J. Fossil Horses. Systematics, Paleobiology, and Evolution of the Family Equidae. Cambridge, Cambridge University Press, 1993. 
11. McNamara, Kenneth J. “Evolutionary Trends.” In Encyclopedia of Life Sciences (New York: Macmillan Publishers Ltd, 2001), pp. 1–7. 
12. Litchman, E., C. A. Klausmeier, and K. Yoshiyama. “Contrasting Size Evolution in Marine and Freshwater Diatoms.” Proceedings of the National Academy of Sciences USA 106, no. 8 (2009): 2665–2670.
13. Tattersall, Ian. The Fossil Trail: How We Know What We Think We Know About Human Evolution. New York: Oxford University Press, 2008. pp. 89–198. 
14. Darwin, Charles. On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life. London: Penguin Books, 1985. p. 292.
15. Hunt, Gene. “Evolution in Fossil Lineages: Paleontology and The Origin of Species.” Supplement American Naturalist 176 (2010): S61–S76. 
16. Clack, Jennifer A. Gaining Ground: The Origin and Evolution of Tetrapods. Bloomington, IN: Indiana University Press, 2002; Daeschler, Edward B., Neil H. Shubin, and Farish A. Jenkins, Jr. “A Devonian Tetrapod-Like Fish and the Evolution of the Tetrapod Body Plan,” Nature 440, no. 7085 (2006): 757–63; Shubin, Neil H., Edward B. Daeschler, and Farish A. Jenkins, Jr. “The Pectoral Fin of Tiktaalik roasae and the Origin of the Tetrapod Limb.” Nature 440, no. 7085 (2006).): 764–71; Downs, Jason P., Edward B. Daeschler, Farish A. Jenkins, and Neil H. Shubin. "The Cranial Endoskeleton of Tiktaalik roseae." Nature 455, no. 7215 (2008): 925–9. 
17. Carroll, Robert L. Vertebrate Paleontology and Evolution. New York: W. H. Freeman and Company, 1990. pp. 156–216. 
18. Shipman, Pat. Taking Wing: Archaeopteryx and the Evolution of Bird Flight. New York: Touchstone, 1998. pp. 169–244.  
19. Prothero, Donald R. Evolution: What the Fossils Say and Why It Matters. New York: Columbia University Press, 2007. pp. 271–297. 

A common argument leveled against the theory of evolution is that scientists have not been able to produce the expected transitional fossils that show the change of one species into another. If evolution were true, wouldn’t there be instances of clear intermediary species, like, for example, a species that was half whale and half hippo to show the transition between those two? In this BioLogos podcast, Kelsey Luoma addresses this misconception about what a transitional fossil actually is. Rather than a mix between two related species, transitional fossils point back to the common ancestors that modern species share. The fact is that the number of transitional species is massive and it grows with each passing year. Given the rarity with which organisms are actually fossilized, the amazing thing is actually the completeness of the fossil record, not its incompleteness. The transitional species story strongly supports, and certainly does not disprove, evolutionary theory. ¹

1. To hear the full audio clips which have been referenced go to:

• Rational Response Debate with Kirk Cameron (from Way of the Masters)
• Behind the Scenes with Dr. Neil Shubin (from Cincinnati Museum Center)
• Mark Norell Publishes New Archaeopteryx Findings (from American Museum of Natural Sciences)
• Texas A&M Professor Discusses Findings of Autralopithecus Sediba and its Relationship to Humans (from Texas A&M University)
• Intro/outro music composed by Martin Minor (Minor2Go).

An audio only version of the podcast can be downloaded here.

For more than a century, evangelicals and fundamentalists have typically rejected both evolution and higher biblical criticism. Sometimes there are good reasons: the claims of some biblical scholars are so outrageous and the claims of some scientists so anti-religious, that a strongly negative response is entirely appropriate. Too often, however, the evangelical encounter with modern science conforms to what historian Mark Noll has called “the scandal of the evangelical mind”—namely, “that there is not much of an evangelical mind.” Attitudes toward science have been crucial to this analysis. As Noll says, “since 1960 creationism has done more than any other issue except abortion to inflame the cultural warfare in American public life.” (p. 192)

Readers who want to know more about Noll’s book and its reception should go here and here. His conclusions about evangelicals and science are fully consistent with those I am about to present.

Evangelicals in Tension with Science

Evangelicals exhibit considerable tension and ambivalence when it comes to science, especially human evolution. On the one hand, evangelicals enthusiastically embrace the findings of science, when it comes to most applications in medicine and engineering. They also accept the experimental sciences, such as physics, chemistry, physiology, or thermodynamics. They have no problems with gravitation, the periodic table, the circulation of the blood, or the law of entropy. Here, their attitude is highly empirical: if it can be shown from repeatable experiments and observations, it’s true and presents no challenge whatsoever to religious belief.

On the other hand, evangelicals are quite hesitant to accept some conclusions of the so-called historical sciences, such as geology, cosmology, and evolutionary biology. Fundamentalists reject the very legitimacy of those sciences, and have created their own alternative explanation, “creation science,” which comports with their particular views of biblical authority and hermeneutics. Evangelicals are more ambivalent. As we’ve seen, many evangelicals accept the big bang and modern geology, with a 4.65 billion-year-old earth and the enormously long history of living things before humans arrived on the planet. But evolution–understood here to mean the common descent of humans and other organisms–presents very serious problems for many, perhaps most, evangelicals. This motivates them to look for alternative views.

The alternatives evangelicals embrace are precisely those we have studied in this series. Some eagerly support the YEC view. Others prefer one of the many varieties of the OEC view. Many like the strident tone of the ID movement, with its vigorous assault on biological and cultural “Darwinism” and its near-universal rejection of human evolution. For most evangelicals, however, TE is probably not a viable option at present, for biblical and theological reasons.

Reconciling Evolution with Scripture

Most evangelicals do not see any reasonable way to combine human evolution with the following beliefs:

• the uniqueness of humans, who alone bear the “image of God”
• the fall of Adam and Eve, the original parents of all humans, from a sinless state, by their own free choices to disobey God
• the responsibility of each person for their own actions and beliefs, within a universe that is not fully deterministic
• the redemption of individual persons by the atoning sacrifice of Christ.

Evangelicals cannot and must not be separated from these crucial beliefs about human dignity, freedom, responsibility, sin, and redemption. The 64-dollar question is: can these beliefs be maintained without simultaneously affirming the necessity of an historical, separately created first human pair? The answer is probably in the hands of evangelical academics, especially theologians and biblical scholars. Can they be persuaded that the scientific evidence for evolution is sufficiently strong to warrant a re-examination of the traditional view? Can a credible gospel and credible science be harmonized?

There exists an enormous gap between popular conceptions of science–conclusions, methods, and attitudes–and those of scientists themselves. This gap is not unique to science among practitioners of specialized knowledge, and it is not unique to evangelicals among the lay public. But it is real and very significant, and it affects theologians and biblical scholars no less than anyone else. Those who try to bridge this gap are mostly scientists (in their role as educators at colleges and universities and insofar as they write books for lay readers) and science journalists. Many influential members of those professional communities are skeptical or even strongly hostile toward Christian beliefs, and this can exacerbate an already difficult state of affairs. If ways can be found to popularize good science, while showing appropriate sensitivity to the concerns of evangelicals, it would be a very good thing.

Signs of Hope

Certainly there are reasons to hope. The conversation about science and religion is considerably broader now than it was at the time of the Scopes trial in 1925. Back then, many Protestants faced a very grim choice. On the one hand, they could follow politician William Jennings Bryan and the fundamentalists, rejecting modern science in the name of biblical authority and orthodox beliefs. On the other hand, they could follow theologian Shailer Mathews and the modernists, rejecting biblical authority and orthodox beliefs in the name of modern science. There was no one out there like John Polkinghorne, Francis Collins, Joan Centrella, Owen Gingerich, Simon Conway Morris, William Phillips, or Ian Hutchinson—to name just a few of the many top scientists today who accept evolution while affirming the divinity of Jesus, the bodily resurrection, and the actual divine creation of the universe. But they are all scientists, not theologians (except for Polkinghorne, who is both). In Galileo’s day, it was the scientists who eventually convinced the theologians and biblical scholars to accept Copernicus’ theory of the earth’s motion around the sun. But, it took a long time, and the process was difficult and often painful. Thus far, the biblical scholars and theologians who have tried to move the conversation forward have not been very well received, as Richard Ostling has so capably reported. I suspect we are in for more of the same.

It’s Your Turn to Talk

That’s what I think. What do you think? I’ll mainly be listening quietly, since I’ve now said all I wanted to say. Thank you all for hanging in there for ten months—far longer than I had originally anticipated. After a short respite I’ll return with a new series, but I’ll keep the topic under wraps for the time being.

According to Merriam Webster, the term “intelligent design” has been used since at least 1847, in reference to “the theory that matter, the various forms of life, and the world were created by a designing intelligence.” That’s a decent definition, also consistent with those offered by today’s proponents of intelligent design (ID). For example, the leading ID think tank, The Discovery Institute (Seattle), has this:

Intelligent design refers to a scientific research program as well as a community of scientists, philosophers and other scholars who seek evidence of design in nature. The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.

And in the opening sentence of a book he edited with philosopher Michael Ruse, ID theorist William Dembski said, “Intelligent Design is the hypothesis that in order to explain life it is necessary to suppose the action of an unevolved intelligence.” (Debating Design, p. 3)

On the other hand, while a recent contest on a prominent intelligent design (ID) website uncovered several other early uses of the term, it is important to note that it does not always mean exactly the same thing in each reference. The term itself has an interesting history, and while ID authors obviously did not invent the term “intelligent design,” they have given it specific content in recent years. Indeed, they have even removed content in some cases: a point I will return to later is that, though it seems the only viable candidate for such an “unevolved intelligence” is God, ID proponents sometimes seem to do cartwheels to avoid saying as much. When a term has such a complicated past, there simply is no substitute for looking at specific references in their own contexts as we move to seeing how ID plays out today as one of the 5 ways of relating science and the Bible.

Interestingly, many Protestant “modernist” scientists and theologians from William Jennings Bryan’s day (see my previous column) unhesitatingly endorsed the idea that a designing intelligence lay behind nature. At least one such person, Nobel prize-winning physicist Arthur Holly Compton, even used the very term “intelligent design” in an address he gave at a Unitarian church in 1940: “The chance of a world such as ours occurring without intelligent design becomes more and more remote as we learn of its wonders.” (Quoting his pamphlet from 1940, The Idea of God as Affected by Modern Knowledge, p. 13. For more about this aspect of Compton’s views, click here.) However, Compton regarded design as a philosophical and theological inference from science, not an explanation within science to be invoked when other explanations fail. He also accepted the common ancestry of humans and other organisms. This is a significant difference from the ID movement today, which offers ID as a scientific alternative to Darwinian evolution and (at least in many cases) seeks to undermine public confidence in common ancestry (even though ID per se is not actually opposed to it).

If any ID proponents are sympathetic to the type of religious modernism that Compton and his friends embraced, I cannot tell you who they are. In a curious, ironic twist, ID is often used by conservative Christian apologists partly to defend a cluster of traditional theological and hermeneutical positions that none of the modernists would have defended. A further irony: the intellectual descendants of the modernists—those scientists and theologians who occupy the left wing of the modern “dialogue” of science and religion—exhibit a studied avoidance of the term “design,” disconnecting them on that score from the modernists of the 1920s.

Many other contemporary writers, including some evangelical TEs, are also reluctant to use the word “design,” precisely because in their view it has been co-opted by ID proponents and they do not want readers to misunderstand their position(s). They may agree with ID proponents that certain features of the universe reflect divine design, but because they do not see design as a scientific explanation they employ other language. (Likewise, the YECs have co-opted the word “creationism” to mean just one specific understanding of God’s creative activity, leading most advocates of other views either to provide their own definitions of the word or else to avoid using it altogether. Politics dogs this conversation at every turn.)

Core Tenets or Assumptions of Intelligent Design

With that bit of historical context for the term “Intelligent Design,” let’s now look at the first of the Core Tenets of this perspective in its current state, and as it is most often used by those associated with the Intelligent Design movement.

(1) The Bible is NOT to be mentioned (at least for now); ditto for “God” and “theology” as far as possible.

This is a deliberate strategy, adopted for political reasons to keep arguments at the level of philosophy and science. Here, “political” refers to the American political system, with its constitutional disestablishment of religion, not to partisan politics. Since the 1980s, federal courts have consistently ruled that “creationism” (which was specifically of the YEC variety in the relevant cases) is sectarian religion, not science, and therefore it cannot be taught in public school science classes. Anxious to avoid a similar fate, proponents of ID always want to ensure that they are not perceived as advocates of “creationism.” The less they mention God and the Bible, the reasoning goes, the less likely they are to fall afoul of those decisions.

The First Amendment to the U.S. Constitution, pertaining to the freedom of religion and the freedom of the press.
Source: http://www.rochester.edu/college/psc/images/Courses/Spring2008/FirstAmendment.png

Phillip Johnson, the former law professor who effectively began the ID movement some twenty years ago, has put it bluntly: “To put things on a more rational basis, the first thing that has to be done is to get the Bible out of the discussion.” He quickly adds, “This is not to say that the biblical issues are unimportant; the point is rather that the time to address them will be after we have separated materialist prejudice from scientific fact.” (“The Wedge: Breaking the Modernist Monopoly on Science,” Touchstone: A Journal of Mere Christianity, July/August 1999, p. 22.)

If God and the Bible are really to be left out for the time being, then why am I discussing ID in a series on “Science and the Bible”? It’s a fair question. I simply don’t see any way meaningfully to avoid talking about ID apart from the culture wars in which it is embedded (I’ll say more about this in a subsequent column), and the Bible is never far from the surface when the battle being fought involves origins. Conservative Christians sense that ID really is about God—Dembski’s “unevolved intelligence”. As Dembski himself has said, “no intelligent agent who is strictly physical could have presided over the origin of the universe or the origin of life”, and there aren’t a lot of candidates for that job. Many Christians also identify strongly with the ways in which ID seeks to confront the secular establishment, in an explicitly-stated effort to combat what Johnson calls “the modernist scientific and intellectual world, with its materialist assumptions.” (“The Wedge,” p. 23.) They see it as a way of getting traditional theistic perspectives and Christian values back into the academy, once “design” has become an acceptable academic talking point—and it isn’t very far from there to conversations about “science and the Bible.” If this were not so, then why would so much ID literature be published by Christian presses? Indeed, when I tell church audiences with a straight face that ID purports not to be about the Bible at all, I’m usually met with considerable skepticism.

When I’m back in about two weeks, we’ll look at further Core Tenets of ID—the ones that have even less to do with the Bible, explicitly, and more to do with the way we approach the study of the natural world.

With his compelling personal story of becoming England’s “most reluctant convert,” his towering intellect, and his inimitable eloquence, American evangelicals’ lionization of Lewis is certainly understandable.² But when we attempt to lionize people we often ironically end up taming them, paring their claws so that our heroes and our preconceptions can safely cohabitate in our imaginations. But Lewis is no safer a lion than Aslan, and he will not go quietly into our tidy evangelical boxes. To be frank, American Evangelicalism’s infatuation with Lewis is in many respects somewhat odd. For here is a pathologically populist movement with a penchant for Big Tent Revivalism, an obsession with liturgical innovation, a deep-seated suspicion of ecclesiastical tradition, and a raw nerve about the doctrine of justification, falling head-over-heels for a tweed-jacketed, Anglo-Catholic Oxford don—a curmudgeonly liturgical traditionalist who was fuzzy on the atonement, a believer in purgatory, and, as we shall see, whose views on Scripture, Genesis, and evolution position him well outside of American Evangelicalism’s standard theological paradigms. All of that is to say that Lewis was not “just like us”—any of us—and if we would do him justice, we must be prepared to be surprised by Jack.

In what follows, I would like to look at three areas relevant to faith and science discussions where Lewis’s stated views might be surprising for his American Evangelical admirers—namely, his views on Scripture generally and Genesis in particular, his views on Adam and the doctrine of the Fall, and his views on evolutionary science and the myth of ‘Evolutionism.’

Reflections on the Scriptures: Lewis on the Bible, Myth, & Fact

Lewis derived his theological understanding of the Bible from his reading of Scripture, his intimate knowledge of the Church Fathers and the Medieval Doctors, and also from his awareness of modern biblical scholarship. While Lewis was regularly critical of Modernist biblical scholarship’s naturalistic dismissal of the miraculous, its pedantry, literary tin-ear, and over-eagerness to conflate Jesus’ story with the stories of pagan mythologies (he had precious little patience for Rudolf Bultmann, for instance ), he was not at all given to the knee-jerk reactionary Fundamentalism which has held so much sway in American Evangelical culture. In fact, Lewis incorporated many of the more well-supported conclusions of modern biblical criticism into his theology of Scripture, not least critical opinions about the historicity of much of the Old Testament. In good Anglican fashion, Lewis creatively drew upon the deep resources of the Church’s grand Tradition in order to think through the contemporary problems posed by modern critical scholarship. Here I wish to focus on three features of Lewis’s theological conception of Scripture—his understanding of the Bible as being incarnational and sacramental in character, and Christotelic in focus—before turning to his theological reading of Genesis 1-3.⁴

Inspiration and Incarnation

According to Lewis, the Bible is both a vessel of the divine Word and also a profoundly human collection of documents. In his longest, most substantive piece on Scripture, chapter XI of Reflections on the Psalms, Lewis frames a thoroughly incarnational understanding of the Bible:

The human qualities of the raw materials show through. Naïvety, error, contradiction, even (as in the cursing Psalms) wickedness are not removed. The total result is not “the Word of God” in the sense that every passage, in itself, gives impeccable science or history. It carries the Word of God; and we (under grace, with attention to tradition and to interpreters wiser than ourselves, and with the use of such intelligence and learning as we may have) receive that word from it not by using it as an encyclopedia or an encyclical but by steeping ourselves in its tone or temper and so learning its overall message.⁵

Lewis’s reference to “[the] human qualities” of the Bible’s “raw materials” is suggestive. As Peter Enns puts it in his book Inspiration & Incarnation: Evangelicals and the Problem of the Old Testament, the Incarnation of the Son and the inspiration of Scripture are “analogous.”⁶ Lewis clearly agrees. He goes on in the chapter to articulate a theology of Scripture precisely in incarnational terms:

For we are taught that the Incarnation itself proceeded “not by the conversion of the godhead into flesh, but by taking of (the) manhood into God”; in it human life becomes the vehicle of Divine life. If the Scriptures proceed not by conversion of God’s word into literature but by taking up of a literature to be the vehicle of God’s word, this is not anomalous.⁷

According to Lewis, the means whereby God gives us Scripture is not by faxing us transcripts of inner-Trinitarian dialogue direct from Heaven, but rather, on analogy with the Incarnation, by taking up very human literature and utilizing it to communicate His Divine life to us.

“We might have expected, we may think we should have preferred, an unrefracted light giving us ultimate truth in systematic form—something we could have tabulated and memorised and relied on like the multiplication table.”⁸ But God has instead deigned to give us a very human book, just as He deigned to send us a fully human Savior. Lewis makes this point most poignantly in his Introduction to J.B. Phillips’s Letters to Young Churches where he writes:

The same divine humility which decreed that God should become a baby at a peasant-woman’s breast, and later an arrested field-preacher in the hands of the Roman police, decreed also that He should be preached in a vulgar, prosaic and unliterary language. If you can stomach the one, you can stomach the other. The Incarnation is in that sense an irreverent doctrine: Christianity, in that sense, an incurably irreverent religion. When we expect that it should have come before the World in all the beauty that we now feel in the Authorised Version we are as wide of the mark as the Jews were in expecting that the Messiah would come as a great earthly King.⁹

For Lewis, God’s work in the inspiration of Scripture not only communicates but also emulates God’s humble, self-effacing work in the Incarnation. If the heart of Christianity, “an incurably irreverent religion,” should be the Incarnation, “an irreverent doctrine,” then it ought to come as no surprise that that doctrine should be most fundamentally communicated via an irreverent book.

A corollary of Lewis’ incarnational and sacramental view of Scripture is that when it comes to studying the Scriptures we must be prepared to be surprised. Lewis warns against “the Fundamentalist’s” procedure of attempting to frame our ideas of Scripture a priori, deducing parameters for what the Scriptures can and cannot be from our preconceptions about God. Lewis thinks such an approach to be a nonstarter:

[There] is one argument which we should beware of using…: God must have done what is best, this is best, therefore God has done this. For we are mortals and do not know what is best for us, and it is dangerous to prescribe what God must have done–especially when we cannot, for the life of us, see that He has after all done it.¹⁰

Instead, says Lewis, we should take a humble, a posteriori approach, looking and seeing just what kind of book it is that God has actually given us before making grand doctrinal declarations. “To a human mind,” Lewis recognizes, an incarnational Bible “seems, no doubt, an untidy and leaky vehicle.”¹¹ But it appears that this is what God has given us, and we must trust that God knows what He is doing. As Lewis says, “Since this is what God has done, this, we must conclude, was best.”¹²

Myth Became Fact

For Lewis, the Word is also like the sacrament. Just as ordinary water, bread, and wine are taken up into and become conduits for and communicators of the Divine life that we so desperately need, so, also, all-too-ordinary human writings are taken up into and become conduits for and communicators of the Divine life and word. In Lewis’s view, we must receive the Divine word by approaching Scripture in a sacramental manner. We “receive that word,” as Lewis says, again, “not by using [Scripture] as an encyclopedia or an encyclical but by steeping ourselves in its tone or temper and so learning its overall message.”¹³ For Lewis, at least when it comes to the Old Testament, receiving the Word means more than simply paying critical attention to the surface meaning of the text, the sensus literalis. Instead, we must press beyond the surface to the sensus plenior, to the “second sense” of the Old Testament, namely, Christ Himself. “It is Christ Himself, not the Bible, who is the true word of God,” Lewis once wrote in a private letter. “The Bible, read in the right spirit and with the guidance of good teachers, will bring us to Him.”¹⁴ While such Christological sensus plenior interpretation may have fallen out of favor with many Protestants (to say nothing of thoroughgoing Modernist historical-critics), Lewis believes that “[we] are committed to it in principle by Our Lord Himself.”¹⁵ Citing Jesus’ words to His disciples on the road to Emmaus, Lewis argues that Christ “accepted—indeed He claimed to be—the second meaning of Scripture.” Citing a litany of Dominical sayings and New Testament texts, Lewis is clear that Christ is mysteriously the true spiritual center, climax, coherence, sum, and substance of the Old Testament Scriptures.¹⁶

Lewis stands in good company in thinking along these lines. The “good teachers” from which Lewis learned this hermeneutic are undoubtedly Aquinas, Bernard of Clairveaux, Augustine, Origen, and Irenaeus, not to mention the Apostles and Christ Himself. In short, Lewis is standing within the mainstream tradition of pre-Reformation theological interpretation. But Lewis is not simply striking a traditionalist posture. Like a scribe trained for the Kingdom, he is prepared to bring forth treasures new and old. By positioning himself within the grand tradition of pre-modern theological interpretation, Lewis frees himself to follow his highly-attuned modern literary-critical instincts regarding the historicity of much of the Old Testament while simultaneously upholding both a robust belief in the historicity of the Incarnation and a vital theological hermeneutic. He writes:

The earliest stratum of the Old Testament contains many truths in a form which I take to be legendary, or even mythical—hanging in the clouds, but gradually the truth condenses, becomes more and more historical. From things like Noah’s Ark or the sun standing still upon Ajalon, you come down to the court memoirs of King David. Finally you reach the New Testament and history reigns supreme, and the Truth is incarnate. And “incarnate” here is more than a metaphor. It is not an accidental resemblance that what, from the point of view of being, is stated in the form “God became Man,” should involve, from the point of view of human knowledge, the statement “Myth became Fact.”¹⁷

He sets up the above paragraph by saying, “[The Christian story] is like watching something come gradually into focus; first it hangs in the clouds of myth and ritual, vast and vague, then it condenses, grows hard and in a sense small, as a historical event in first century Palestine.”¹⁸ Apart from the Incarnation, then, much of the Old Testament would be but “myth,” “ritual,” and “legend.” These elements of the Old Testament only become tangible historical “Fact,” for Lewis, in the person and work of Christ.

Next time, Williams looks at how this understanding of Scripture framed Lewis' reading of Genesis 1-3.

Note

1. C.S. Lewis, A Grief Observed, (San Francisco: Harper Collins, 2001), 66
2. See Smietana, Bob, “C.S. Lewis Superstar: How a reserved British intellectual with a checkered pedigree became a rockstar for evangelicals,” http://www.christianitytoday.com/ct/2005/december/9.28.html
3. “Through what strange process has this learned German gone in order to make himself blind to what all men except him see?,” wrote Lewis in “Modern Theology and Biblical Criticism,” in Walter Hooper, ed., Christian Reflections (Grand Rapids: Eerdmans, 1995), 156
4. I owe the word “christotelic” to my teachers at Westminster. See especially the discussion in Peter Enns’ Inspiration and Incarnation: Evangelicals and the Problem of the Old Testament, (Grand Rapids: Baker Academic, 2005)
5. Lewis, Reflections on the Psalms, (San Diego: Harcourt Inc., 1986), 111-12
6. See note xii above.
7. Lewis, Reflections on the Psalms, 116
8. Ibid, 112
9. Lewis, “Modern Translations,” in God in the Dock, (Grand Rapids: Eerdmans, 1970), 230
10. Lewis, Reflections on the Psalms, 112
11. Ibid
12. Ibid, 113
13. Ibid, 112
14. Lewis in a letter, 8 November, 1952, in W.H. Lewis, ed., Letters of C.S. Lewis, (New York: Harcourt Brace Jovanovich, 1966), 247 cited in Martindale and Root, The Quotable Lewis, 72
15. Lewis, Reflections on the Psalms, 117
16. Ibid, 117-19
17. Lewis, “Is Theology Poetry?,” in The Weight of Glory and Other Essays, (New York: Harper Collins, 2001), 129
18. Ibid

Introduction

One of the reasons that some of us are hesitant to accept evolutionary creation is that it seems to make God responsible for the suffering and death of innumerable creatures over millions of years—before humans ever existed or sinned against their creator. Since we believe in and worship a God who is loving, benevolent, and all-powerful, it sounds quite implausible that our God would have created a world like that; therefore, any scientific evidence for evolution must be incorrect.

Other people look at the scientific evidence for evolution and find a compelling case that it has taken place during our earth's history. On this basis they may conclude that if evolution is true, then the belief in an all-powerful, perfectly good God must be false!

The trouble with both of these views is that they tend to invoke a completely abstract, philosophical god, not the living God of the Bible—the God who became a human being, experienced unimaginable suffering, and died in a grotesque and humiliating public display. The death of Jesus completely defied the expectations (and common sense) of his followers, as well as the expectations of any “rational” understanding of the way the Creator of the universe should act in the world. On the cross, in the person of Jesus, God took upon himself far more suffering than any creature has ever experienced.

If God himself is willing to die, particularly in such a gruesome way, then perhaps we should at least consider the possibility of God allowing the death of other creatures, too. But would this really be compatible with what we know of God through Scripture? In this essay, we will explore this quandary through a “theology of the cross”, a concept articulated by pastor George Murphy in his book Cosmos in the Light of the Cross.¹

Theology of the cross

Before we jump into the theological problems associated with evolution, let’s take a look at how we understand Christian theology itself. For the reformer Martin Luther, any theology (or science) that tries to reach knowledge of God apart from the cross is bad theology.² Instead, Luther pointed to a theologia crucis, in which the true God is seen first and foremost “through suffering and the cross”. To make his point even clearer, Luther insisted that “the CROSS alone is our theology”.³ It is the lens through which we view everything.

Of course Martin Luther, having lived in the 16th century, was not aware of the vast history of life on our planet (or any other aspect of modern science, for that matter), but George Murphy draws from Luther’s teachings the foundation that all human knowledge begins with the Word made flesh and crucified.⁴ With the cross of Christ as the ultimate framework through which we view reality, we are bound to view the processes of nature quite differently. As Murphy explains it,

A theology of the cross is an explication of belief in a God who becomes a participant in the history of the universe and thereby shares in the suffering, loss, and death that are part of worldly experience.⁵

God does not sit idly by and watch unaffected as his creatures suffer, but neither does he swoop in and make everything completely effortless and easy. Instead he chose another way, the crucifixion of Jesus—certainly not the approach that we would have preferred! The apostle Peter went so far as to try to talk Jesus out of it, but he was met with a stern rebuke (Matthew 16:21-23).

Why is evolution so disconcerting to Christians?

The problem of suffering throughout all of human history is troubling enough for us to reconcile with a loving, personal God. But in addition to that, the discovery of vast numbers of fossils reveals that death has taken place on a far greater scale than we had ever imagined. Both the wide variety of extinct creatures and their sheer numbers is quite staggering, and it raises questions about our Creator:

The picture of a God who is immune from suffering and death but who forces organisms through millions of generations and extinction is disturbing to those who believe in a God of love.⁷

The mass extinction of life on earth was already well established by the early 19th century—decades before Darwin’s research—and extinction can be empirically verified independent of any theory of evolution.⁸ The fact that the earth’s crust is a veritable graveyard of long-lost creatures is deeply troubling, and as late as the 1790’s, distinguished intellectuals such as Thomas Jefferson denied the very possibility of extinction.⁹

But in addition to the reality of species extinction, the theory of evolution by natural selection proposes that new species also arise in an environment containing widespread pain and death. Both the creatures that are now living and those that are gone are tainted by an “acrid smell of death”.¹⁰ It makes us wonder, if our Creator is not the God of the dead, but of the living (Mk. 12:27), where is God’s presence in the evolutionary picture?

In all honesty, creation through evolution is not what we would expect from God, but Scripture is full of examples in which God acts in unexpected ways. After all, God’s choosing to undergo an agonizing death on a cross is not what we would expect from the all-powerful Creator of the universe, either. In both cases, new life comes about through pain, suffering, and death. As George Murphy puts it,

A priori ideas about God have to be overcome, and God's character has to be learned from God's self-revelation.¹¹

God’s fullest self-expression is in Jesus Christ himself, one who is intimately familiar with and personally endured creaturely pain and death. The theology of the cross reveals that God's self-revelation takes place in situations of suffering, loss, and apparent hopelessness, much like situations that occur through natural selection.¹²

The crucifixion is disconcerting too

Not only is creation through evolution an unexpected and unsettling process, but so is the crucifixion of Jesus! Killing someone by hanging them on a cross is an unbearably painful, prolonged, humiliating form of death. It was such a horrific type of public execution that it wasn't until after the Roman Empire stopped the practice of crucifixion—and people no longer witnessed it personally—did the cross become a visual object of devotion.¹³ Our culture is sufficiently removed from crucifixion that we are desensitized to its original significance, but to connect it to our current context, imagine the reaction you would get by wearing jewelry designed to look like an electric chair.¹⁴

Once we are more attuned to the brutality of crucifixion, it seems all the more striking that the cross is the sign of God’s work, what George Murphy calls “the trademark of God”.¹⁵ The suffering and death of Jesus is featured prominently in the Gospels, but the crucifixion-resurrection pattern is strongly resonant within the Old Testament, too. Israel suffered and toiled as slaves in Egypt for centuries before they were rescued in the Exodus, bringing life to a people who were spiritually dead. Centuries later, the nation of Israel would experience death again when the Babylonians destroyed the Davidic monarchy, burned their Temple, killed their people, and sent many into exile.¹⁶ Neither Israel (God’s chosen people) nor Jesus (God’s own son) were spared from death and suffering; rather, suffering seems to have been the way in which God re-forms and renews humanity to fully bear His own image.

Redemption extends to all of creation

Fortunately, God’s story does not end with death. God gives new life after his creatures have been subjected to terrible circumstances. Redemption was promised to Israel itself—Ezekiel’s vision of the valley of dry bones describes how God would renew His chosen people (Ezek 37:1-14). Later, the astonishing resurrection of Jesus made salvation possible not only for Jews, but for all people in Christ (Gal 3:26-29). Ultimately, the New Testament makes it clear that God’s renewal will encompass the entire Creation:

For God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross. (Colossians 1:19-20)

With all wisdom and understanding, he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, to be put into effect when the times reach their fulfillment—to bring unity to all things in heaven and on earth under Christ. (Ephesians 1:8-10)

Christians are accustomed to thinking of the death of Christ in regard to humans, but our culture rarely acknowledges God plan for the redemption of His entire creation. This is partly attributable to the fact that discussions of creation and origins are often separated from the topic of salvation.¹⁷ In doing so we tend to marginalize Jesus as we argue about Genesis. Rather than fall into this trap, if we view nature through a theology of the cross, we will see Christ as both the alpha and the omega point in discussions of life’s history and life’s future. With this perspective, we are more apt to sense our solidarity with the rest of creation as we wait in eager anticipation of a glorious future:

The creation waits in eager expectation for the children of God to be revealed. For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope that the creation itself will be liberated from its bondage to decay and brought into the freedom and glory of the children of God. (Romans 8:19-21)

Conclusion

As part of the Church’s conversation about the problem of natural evil, this essay is meant to be a brief introduction to a “theology of the cross”. One can explore this concept in greater detail in Murphy’s book The Cosmos in the Light of the Cross. While there is a lot more to be said, let me conclude with the following observation: though evolution may not be compatible with some interpretations of Christianity, evolutionary creation is certainly compatible with the crucified Christ and the theology of the cross. In the person of Jesus, God suffers with the world and ultimately redeems it. As George Murphy puts in, “The world's pains are God's stigmata.”¹⁸

Explore this Topic Further

• Miller, Keith. “And God saw that it was good”: Death and Pain in the Created Order. BioLogos series
• Murphy, George L. The Cosmos in the Light of the Cross. Harrisburg, PA: Trinity Press, 2003.
• Murphy, George L. “Cross, Evolution, and Theodicy: Telling It Like It Is”. In The Evolution of Evil. Edited by G. Bennett, M.J. Hewlett, T. Peters, and R.J. Russell. Göttingen: Vandenhoeck & Ruprecht, 2008.
• Southgate, Christopher. The Groaning of Creation: God, Evolution, and the Problem of Evil. Louisville, KY: Westminister John Knox Press, 2008.

Notes

1. Murphy, George L. The Cosmos in the Light of the Cross. Harrisburg, PA: Trinity Press, 2003.
2. Murphy, p34
3. “CRUX Sola Est Nostra Theologia,” in D. Martin Luthers Werke, Kritische Gesammtausgabe (Weimar: Hermann Boehlau, 1892), 5:172. The captitalization is in the original. Cited in Murphy, p26.
4. Murphy, p108
5. Murphy, p4
6. Murphy, p43
7. Murphy, p3
8. Some Christians ascribe animal death to some combination of Adam’s fall and Noah’s flood, but this does not resolve the problem that the animals are still suffering and dying through no fault of their own. See Keith Miller’s BioLogos series Death and Pain in the Created Order for the limitations inherent in a fall-based theodicy.
9. Rudwick, Martin. The meaning of fossils: Episodes in the history of paleontology. Chicago, University of Chicago Press, 1985.
10. See Jeff Schloss’ BioLogos essay Evolution, Creation, and the Sting of Death
11. Murphy, p63
12. Murphy, p122
13. Murphy, p27
14. This example is drawn from an evangelical outreach event held by a Christian student group in Innsbruck, Austria. On campus one day, they started conversations with their classmates by asking the question, “Would you wear an electric chair on your neck?”
15. Murphy, George L. The Trademark of God: A Christian Course in Creation, Evolution, and Salvation. Wilton, Conn.: Morehouse-Barlow, 1986.
16. Murphy, Cosmos in the Light of the Cross, p 31-32.
17. Murphy, p35
18. Murphy, p87

Behe and IC

Since we have previously explored Behe’s idea of irreducible complexity in an entire series, we will not revisit it here in great detail. It is important, however, to reemphasize how Behe defines irreducible complexity (IC). As we noted in the first part of that series, Behe frames his ideas on IC as a counter to Darwin’s ideas of gradualism.

For Behe, the argument for IC is a critique of gradual evolutionary processes, of the kind that Darwin saw as necessary for his theory to hold. When Behe introduces and defines IC in his book Darwin’s Black Box, he has a key quote from Darwin on gradualism explicitly in view:

Darwin knew that his theory of gradual evolution by natural selection carried a heavy burden: "If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."

It is safe to say the most of the scientific skepticism about Darwinism in the past century has centered on this requirement… critics of Darwin have suspected that his criterion of failure had been met. But how can we be confident? What type of biological system could not be formed by “numerous, successive, slight modifications”?

Well, for starters, a system that is irreducibly complex. By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution.

(Darwin’s Black Box, p. 39)

The definition of an IC system is thus straightforward: it is a matched group of components, where all the components are necessary for the function of the system. The necessity of each component can be demonstrated by attempting to remove it – if the system no longer works if even one component is removed, it is by definition IC.

Behe and exaptation

The standard response to Behe’s argument from IC is to discuss the evolutionary concept of exaptation: that new systems and functions are cobbled together from components that have functional roles in other systems already present in the cell. Behe discusses, and ultimately dismisses this idea in Darwin’s Black Box as follows:

In Chapter 2 I noted that one couldn’t take specialized parts of other complex systems (such as the spring from a grandfather clock) and use them directly as specialized parts of a second irreducible system (like a mousetrap) unless the parts were first extensively modified. Analogous parts playing roles in other systems cannot relieve the irreducible complexity of a new system; the focus simply shifts from “making” the components to “modifying” them. In either case, there is no new function unless an intelligent agent guides the setup.

So for Behe, two points are clear: parts selected for function in one system cannot be exapted for use in other systems since they would require too many modifications; and the emergence of a new function is the indication that an intelligent agent is guiding the process.

Behe has responded to my previous posts to claim that the tandem duplication event that brought about the Cit+ actualization event should not be considered a gain-of-FCT mutation under his criteria:

The gene duplication which brought an oxygen-tolerant promoter near to the citT gene did not make any new functional element. Rather, it simply duplicated existing features. The two FCTs comprising the oxygen tolerant citrate transporter locus -- the promoter and the gene -- were functional before the duplication and functional after. I had written in my review that one type of mutation that could be categorized as a gain-of-FCT was gene duplication with subsequent sequence modification, to allow the gene to specialize in some task. Venema thinks the mutation observed by Lenski is such an event. He has overlooked the fact that there was no subsequent sequence modification; a segment of DNA simply tandemly duplicated, bringing together two pre-existing FCTs.

As an aside, quibbling over whether this mutation constitutes a “genuine gain-of-FCT” mutation is not my purpose here, since the definition is Behe’s to define, and I am not aware of anyone else in the scientific literature who uses Behe’s definitions. That said, I consider it passing strange to claim that a series of events that produced a gene that has a new sequence and functional properties distinct from either of its component parts does not constitute the production of a new “functional coded element.” If nothing else, it is a functional coded element that has not previously existed, cobbled together from parts of other functional coded elements, displaying new, adaptive properties. If according to Behe’s definition that’s not “new” or a “gain” then I guess it’s not, but that seems to me to torture the words “new” and “gain” beyond recognition. But I digress.

The important point for our purposes, however, lies elsewhere. Note carefully how Behe describes the Cit+ actualization event. By dividing the new aerobic citrate transporter gene into two previously existing FCTs, Behe is describing an exaptation event. The one FCT (the aerobic promoter) starts off as a necessary component of a gene transcribed when oxygen is present. As such it is under selection for that function, which has nothing to do with expressing a citrate transporter. The second FCT (the citrate transporter amino acid coding sequence) is under selection to be a citrate transporter, which has nothing to do with the function of the gene the promoter comes from. The Cit+ actualization event, then, exapts these two FCTs by placing them together to create a new function (which Behe does not mention).

And here’s the kicker: the new system (expression of the citrate transporter when oxygen is present) requires both FCTs in order to work. It has become a system of “well matched, interacting parts that contribute to the basic function” (i.e. transporting citrate in the presence of oxygen) “wherein the removal of any one of the parts causes the system to effectively cease functioning.”

In other words, it is a new IC system – a small and relatively simple system, yes, but nonetheless IC. Now, I’m fairly sure that Behe would not define this system as IC, since the documentation of an IC system evolving would seriously undermine his thesis. I am interested, however, in how he will handle this development, on two fronts. First, he would need to explain specifically why two exapted FCTs that are required together for a basic function does not constitute an IC system (if indeed he wishes to preserve his definition). Secondly, given that he allows for exaptation in this case, he needs to explain how exaptation is not a threat to IC in general. In Darwin’s Black Box he disallows exaptation altogether, but that option is no longer on the table.

In the next post in this series, we’ll continue to explore the evidence for exaptation as a means to build new FCTs, and go on to examine the implications of this evidence for Douglas Axe’s proposed limit to evolutionary mechanisms.

For further reading:

Blount, Z.D., Barrick, J.E., Davidson, C.J. and Lenski, R.E. (2012). Genomic analysis of a key innovation in an experimental Escherichia coli population. Nature 489; 513- 518.

Michael J. Behe, Darwin’s Black Box: The Search for the Limits of Darwinism (New York: Free Press, 2006).

Michael J. Behe, The Edge of Evolution: The Search for the Limits of Darwinism (New York: Free Press, 2007).

Michael J. Behe (2010). Experimental evolution, loss-of-function mutations, and “The first rule of adaptive evolution”. The Quarterly Review of Biology 85(4); 419-445.

In 1774, the French chemist Antoine Lavoisier replicated the relevant experiments in more controlled ways to demonstrate that mass was conserved during combustion. He also renamed the part of the air that burned 'oxygène.' English scientists resisted the French scientist's new name, not least because the English Priestly had already published his discovery of the gas. 'Oxygen' nonetheless entered the common English vocabulary in part due to one of the first popular science books, The Botanic Garden (1791), which included a poem praising the gas using the preferred French name. By coincidence, this book also promoted some early ideas about biological evolution (specifically, it suggested that sexual reproduction might be important to evolution, which might help to explain the popularity of a book of poems about science). It was written by Erasmus Darwin, the grandfather of Charles Darwin, who first proposed the modern form of the theory of biological evolution in his 1859 book, On the Origin of Species.

150 years later, we are discovering that the lines connecting evolution and oxygen run deeper than the Darwin family tree. We now know, for instance, that for roughly half of the Earth's 4.6-billion-years of history, there was little to no oxygen in the atmosphere. Instead, oxygen entered the atmosphere in two major pulses, with one between 2.4 and 2.2 billion years ago, and another between 0.8 and 0.54 billion years ago. Recent evidence suggests that the first pulse may have actually been the largest event in a series of fits and starts beginning at around 2.7 billion years ago that finally produced a stable low oxygen atmosphere by around 1.8 billion years ago.

Remarkably, both episodes of atmospheric oxygenation happened just before explosions in biological diversity. We have spotty evidence of unicellular eukaryotes (cells with nuclei) before 2.4 billion years ago, but the first fossil evidence for large, diverse eukaryotic communities comes at 1.5 billion years ago. If you are a human, this is part of your history; humans are multicellular eukaryotes descended from one of these early unicellular pioneers. Multicellular animal life is an innovation that seems to have required more oxygen: animals don't appear in the fossil record until about 0.61 billion years ago, toward the end of the second pulse of oxygen.

It is, perhaps, not surprising that major evolutionary events in the eukaryotic family tree, including the origin and diversification of the animals, would be tied to or even driven by major changes in atmospheric oxygen abundance. Eukaryotes generally, and animals specifically, are oxygen lovers. As the subjects of Mayow and Priestly died to prove, we require oxygen for respiration. In general, the larger and more organizationally complex we are (for instance, a human versus a slime mold), the more oxygen we require.

But where did all the oxygen come from? Ultimately, it was produced by the bacterial equivalents of the plants in Joseph Priestley's experiment, a group of photosynthetic microbes called the cyanobacteria. These bacteria are the first and only organisms to have evolved the ability to produce oxygen by photosynthesis. In fact, plants are able to photosynthesize only because their cells harbor descendants of one of the early cyanobacteria. We call them chloroplasts and think of them as little cellular organs, but they are actually the great-great-great... granddaughters of a cyanobacterium that long ago gave up its independence in exchange for the stable environment inside a eukaryotic cell. In any case, photosynthesis is the only known geological process capable of producing oxygen at the rates required for the two pulses of atmospheric oxygenation. The first pulse was probably largely accomplished by cyanobacteria, while the second pulse was probably mostly associated with the cyanobacterial denizens of eukaryotic algae.

What is remarkable about all of this is the extent to which modern life and the atmosphere are products of each other's evolution. The tiniest of photosynthetic organisms played one of the most important roles in shaping the sky, and the sky helped to usher in the age of animals! As a Christian and a geobiologist, I do not believe that this relationship is anticipated or predicted by the Biblical creation accounts.

But then again, why should it have been? The original audience for these accounts would have found concepts like bacteria or even oxygen incomprehensible. The people for whom the Bible was originally addressed thought about origins primarily in terms of ongoing national conflicts and the current human condition. Faced with a variety of violent creation myths that reinforced national conflicts, Genesis said that the universe was created to be good, peaceful, and orderly by one god. It specifically listed things worshipped by other nations as creatures of that god, and in the climax of the creation account, Abraham was called by the same god to be a blessing to all the nations through Israel.

I am not claiming that the Bible cannot be read in a way that can shape us in real and meaningful ways today. In fact, for those who believe that the Bible is inspired, part of the meaning of inspiration has to be that the Bible is God's powerful word to both those with no concept of modern science (most of the world's population, both today and in the past) and to those deeply engaged in its practice. But, and this is a big but, we contemporary Americans read the Bible best when we are sensitive to the assumptions of the original audience, carefully observe how the Bible transformed those assumptions, and look for opportunities to do the same thing with our thinking.

I think that it is important for Christians to reflect on the view of origins that science has given us in light of the thinking evident in the Biblical creation accounts. We have to do this because science gives us a story that is inherently without philosophical or theological meaning; it is up to us to give it meaning by understanding it in relationship with our beliefs. For instance, some see the evolutionary history of life and the Earth and give that history meaning by elevating chance and necessity to the level of prime actors in their own modern creation account. This meaning is not inherent to the theory of evolution; it is supplied by an atheistic belief system external to the theory. I suggest that this view mistakes created things (chance and necessity) for the Creator.

Others have preferred to see the regularity of the universe as the action of an orderly God. This is an old approach to natural theology that was popular among many early scientists, and saw God as responsible for doing such things as maintaining the planets in consistent paths around the sun. Still others look for God in the unexplained. This is a newer approach that sees God as acting primarily in short bursts not explainable by the regular, orderly function of the universe. Looking for God in these ways is a little like trying to capture him in a bell jar, an approach that worked perfectly well with oxygen for Mayow, Priestley, and Lavoisier, but one that is unlikely to impress the Creator described in the Bible.

I prefer to see the same history in the light of a God who desires to share aspects of his nature with his creation, notably including his creativity. Just as he has made humans to be creators (with a little 'c'), he has given the rest of our world the gift of being instrumental in its own creation through the process of evolution. This surely must have been part of what God saw when he described his creation as good! It is my hope that the modern American church can learn to see the goodness of creation in things like the evolutionary history of life and the atmosphere, as well.

This post first appeared in October 2009

Genesis is one of my favorite books of the Bible. I read through it probably once every few months and repeatedly grind my Hebrew language skills on its opening chapters. Unlike Leviticus (at least in the opinion of most people I know), the Genesis narrative is exciting and adventurous. Some of our favorite stories come out of the book: Noah and the Ark, The Tower of Babel, Abraham and Isaac, Joseph and the Coat of Many Colors, and so on.

But no story is perhaps as infamous and well known as the creation account (or accounts) as presented in Genesis 1-2. Almost every Christian or Jew, even those less than devout, know the opening words to the tale: “In the beginning, God created the heavens and the earth.” We know that God created the earth in six days. We know Eve was taken from Adam's rib for a companion. We know that God called the general creation “good”, the special creation of man “very good” and, at the very end of it all, took a day of rest (which I'm sure most of us would call “very good.”)

Of course, we know all of this. Yet we challenge it (and are challenged by it), continually, when we consider the variety of interpretations of how this story intersects the world as described by science. With Genesis, are we dealing with a literal scientific account, where “day” means 24-hours; are we dealing with metaphorical “days” in which epochs or periods of time or even processes are being described; or are we readers of a creation mythology from the Ancient Near East that doesn’t have anything directly to do with material origins? Interpretations go on and on, as anyone who has spent any time at all studying the creation debate knows. By and large, however, we can probably categorize Genesis interpreters into three camps: the Young Earth Creationists, the Old Earth Creationists, and the Theistic Evolutionists.

Now, I have the unique benefit of falling into all of these individual camps at one point or another in my life, sometimes even mixing them up. I have made a strong transition from being a die-hard Young Earth Creationist to being convinced that the evolutionary story is, in fact, the more substantiated and evidenced position. I say this with no pride, since my own transition involved many agonizing questions, a whole lot of reading, and a significant internal spiritual battle: what I believed about when and how the earth was created would not only change the way I read Scripture, it would also change certain aspects of how I viewed the Creator.

While I've certainly learned a lot of information on my journey, it was not an accumulation of facts that has kept me following Christ through all the ups and downs, but Jesus himself, and the knowledge that truth is not something which the Christian should find spiritually threatening. Nevertheless, those same ups and downs—and my internalization of each of these views on creation in turn—has provided me with one simple realization about the debate over scripture and evolution: most of us are not so committed to finding the truth about Genesis and creation as we are to sustaining and maintaining our own interpretive boundaries and the boundaries of the communities which influence us. In other words, the debate is often not so much over Genesis—or even over whether we can all follow the same God when we believe different things about how he created—it's over our own ability to be right. I know this because admitting that I was wrong was the most difficult part of my own transition.

Interpretive communities

While I am pretty convinced of the truth of an evolutionary portrait of reality and an ANE reading of Genesis similar to that espoused by scholars like Peter Enns or Bruce Waltke, I can still make this claim about interpretive communities because my intention is not to dissuade others from debating the issues involved, but to ask that we simply recognize our own limits and check them as often as possible. This is part of following Jesus, is it not? Unfortunately, vigorous debate often deteriorates quickly into screaming matches where proponents of one position or another simply are talking heads, speaking past each other and forgetting our fellowship in Christ. We play into the same interpretive competition that the Pharisee and Sadducee scribes were well known for, each claiming to have a proper interpretation of the Scriptures, but all the while forgetting that interpretive arguments matter exceptionally little if a genuine search for God is not at the forefront. This is certainly not to insist that the discussions cease, but rather, to insist that these discussions can only be propelled forward if individuals—of whatever stripe—step outside of their own interpretive boundaries and communities and humbly present themselves before God, seeking His truth alone. It is to insist that “system maintenance” must die along with the self, because only then can we allow Scripture to interpret itself. Unfortunately (and this is an issue that goes way beyond the Genesis text), too many of us are more committed to a specific model than we are committed to seeking God’s truth, whatever inconvenience to us that truth proves to be.

In 2006, for instance, I heard a popular and well-trained Young Earth paleontologist make the following statement: “If all the evidence turns against young earth creationism, I will still believe it because that's what the Bible says.” I followed up with him in a conversation a year later over lunch and quickly realized that I did not misunderstand his statement. For him, the parameters of his convictions were set in concrete and the truth of the overarching story of Christianity rested on these parameters not being crossed. In his view, the Bible absolutely and fundamentally teaches a universe which came into existence 6,000-10,000 years ago; to deny that is to deny Scripture, and if evidence turned up to the contrary one must not alter those parameters but, instead, search (perhaps in vain) for counter-evidence or be willing to live in blind faith. For this paleontologist, confident Christianity hinged on the stability of those borders of interpretation. Transition wasn't allowed.

But I have heard and read statements coming out of the two other camps of thought that share this kind of certainty over interpretation, too. There is a sense of doing injustice to scripture, thereby doing an injustice to Christianity, and, thereby again, doing an injustice to God if one strays from the preferred reading. One Old Earth Creationist remarked in a popular book that an interpretation of Genesis that allows for evolution is a “contradiction in terms” and it's an unfortunate thing to “blame God for it.” Genesis, in the mind of this thinker, specifically precludes any interpretation which leads to the sort of story evolution tells. To think otherwise is to “blame” God for something which he intentionally tells us is otherwise against his nature.

I have equally heard some theistic evolutionists deride—in a very spiritually shallow and personally offensive way—those who do not accept an evolutionary viewpoint. As one who went through an interpretive evolution on biological evolution, I can say confidently that I believe my own transition would have been much easier both intellectually and spiritually if not for feeling as if certain theistic evolutionists accused me of intentionally lying or being mentally ignorant. It seems that all three camps are at least sometimes plagued by the issue of pride—especially in the cases of a few strong advocates. But pride is nothing less than the cement by which interpretive barriers are built, helping them become unmovable walls that protect the interpretive communities within.¹

On the other hand, one of the great benefits of the fall of positivism (or verificationism) and the rise of postmodernism was the realization that total objectivity among individuals is a false conception. And, since individuals make up communities, neither are camps of thought above error and immune from being wrong. Yet way too many Christians continue to approach Genesis as if we can interpret it on its own terms, completely and totally, without reference to our own location in history and culture. We're still functionally positivists. But it is an illusion that we’re above the interpretive fray, and we must realize time and again that we are subjective individuals, affected by a number of factors and people. We are deeply influenced by those that speak into us, those that we trust, and those that we find credible. As W. Randolph Tate writes,

Interpretations...must be consistent with the established interpretive framework of the interpretive community. The worldview of the interpretive community sets the parameters within which interpretations are accepted or rejected.²

The Bible takes a slightly different angle and puts it this way: “for all have sinned and fall short of the glory of God.” In other words, we are not objective data-interpreting individuals but fallen men and women, even as followers of Jesus.

So it’s when groups of folks line up on either side of an issue and make their positions part of their identity that the debate over interpreting Genesis reaches a near stalemate. It's communities against communities, PhDs against PhDs, experts against experts, and—perhaps more internally—interpretive parameters against interpretive parameters. The truth is that as long as we are first and foremost committed to maintaining the community in which we are involved, there will be very little chance of us getting at the real issues and the best conclusions, much less giving an adequate witness to our God, both Creator and Redeemer.

New eyes, fresh air

I mentioned earlier that I spent time in all three major camps of thought on this issue. I was a hard-lined Young Earth Creationist, debating on forums and writing creationist papers in college. I argued for the existence of modern-day dinosaurs, major flood geology, and so on. I was convinced I was right, that defending the truth meant digging my heels deeper into the sand. But two questions plagued my thoughts: first, I asked whether Christianity fell to pieces if I was wrong. Second, I asked whether I was committed to Christ or, rather, to myself and my interpretations. With that as my first major paradigm shift, I eventually came to accept an Old Earth view. I sat comfortably within the Old Earth view for several years, but the Lord was still at work in me, and, once again, brought those two questions to my mind. Back to the books I went, back to the Bible I went, and back to prayer I went.

Through months of extremely difficult and heart-rending transition, I found myself considering a particular reading of Genesis that I would have regarded as unacceptable as a YEC. But then I was confronted with this even more important point about Christianity: often God finds what is unacceptable to us very acceptable to Him! That included me, personally, and I felt the warmth of God’s grace flow over me. In the wake of that change of heart, people accused me of rejecting my background, my Christian education, and my interpretive communities. And, yet—whether I was right or wrong—I knew God accepted my path towards this new reading of Creation as a genuine search for Him. My spiritual struggle—contrary to what I thought while it was happening—was not a struggle to reject bad data and exegesis, it was a struggle to reject myself.

While the “facts” were important, that spiritual struggle was even more so for me. What was God showing me in the midst of it all? Was thinking differently about the creation making me appreciate the Creator less, or more? Did reading Genesis differently mean only that I had been wrong, or that it was somehow less true? What did any of this have to do with my sense of calling to love and serve God and my fellow men? In a way, I’m still figuring this out. But I can absolutely testify that the struggle transformed every single one of these questions. Indeed, for the first time, I believe I saw God as much this-worldly as other-worldly. I saw nature as intimately intertwined with itself, still being woven together by God’s hand. I saw Scripture as a beautiful expression of God’s desire that man should participate in creation. I saw that my fellow men and my fellow Christians were all on a journey, much the way I was. And I saw myself as a flawed, stubborn, and prideful man, yet forgiven for the times I’ve pitted myself and my presuppositions about Scripture against God, its author.

As settled as I am now, I have not forgotten that the common ribbon which ties together all of these transitions is my commitment to keep asking questions within my own circle, too—realizing that God still has much to teach all of us. I have learned the continuing importance of stepping outside of my camp and making sure I haven’t become merely a product of or a willing prisoner to thinking a certain way, unwilling to consider that it and I might be incorrect. I came to realize that everyone (including myself, of course) has stories and life experiences that become the framework in which they read Genesis 1-2. And if I stopped pretending that I, myself, could be perfectly objective, then I also had to stop pretending that those in the community that I trusted were necessarily objective, themselves.

Ultimately, I had to be willing to be wrong and to see that my friends might be wrong, too. That’s not something that any of us are “naturally” very good at, but it is possible when we realize that the world does not depend on us being right, but upon Jesus being right. For me, seeking truth rather than presupposition requires that we all be able to approach the communities that have influenced us deeply, and ask not just “what” they say but “why” they say it. We all have to guard our hearts even more than our heads. Frequently reminding myself to walk back to the edge of my own camp—to follow Jesus’ example and withdraw to a solitary place—has shown me that there is room to breathe outside our familiar interpretive parameters. At certain times, I have found it to be the most refreshing air I've ever tasted.

Notes

1. Though, admittedly, the theistic evolutionists tend to have a greater sense of leeway when it comes to how the claims of Genesis 1-2 affect Christianity as a whole. It would be an odd thing to say that to not interpret Genesis 1-2 as an evolutionary metaphor is to reject Christianity. As far as I know, most Christian evolutionists are very much willing to acknowledge that Young and Old Earth Creationists are still within appropriate spiritual bounds, even if not scientific ones. It seems to me that if individual theistic evolutionists choose an issue about which to be rigid, it’s the Fall and the existence of Adam.
2. Tate, W. Randolpy. Biblical Interpretation: An Integrated Approach. Peabody, MA: Hendrickson, 2008, p 222.

With the complete genome sequence in hand, we knew the sequence and location of our genes, but what we didn’t know was how all those genes are regulated: how do the trillions of cells in our bodies know when to turn on or off all those genes? How do the hundreds of distinct cell types develop and function together, when they are all running on the same DNA “operating system?”

That’s where the ENCODE (short for Encyclopedia of DNA Elements) project comes in. Launched in September 2003, shortly after the announced completion of the Human Genome Project, the goal of the ENCODE project is “to build a comprehensive parts list of functional elements in the human genome, including elements that act at the protein and RNA levels, and regulatory elements that control cells and circumstances in which a gene is active.” In other words, the project seeks to understand how the genome “works.”

Early this month, researchers from ENCODE released more than thirty papers presenting their findings. During a Science magazine online chat, the project’s data coordinator, Ewan Birney, explained the outcome:

The ENCODE project aimed to start our understanding of how the human genome works. We know that (nearly) all the information that determines a human is in the genome, as we all start off as single cell with this DNA. However, we had a patchy understanding of how it works, in particular away from protein coding genes.

To work out how the genome works, we used the fact there are many tiny machines (proteins and RNA - RNA is very like DNA) in each of our cells which know how to "read" parts of the genome. By monitoring where these little molecular machines are on the genome, or how parts of the DNA are copied into RNA (there are quite a few different types of RNA as well), we start to gain some insight into the genome.

We did many such experiments, across different cell types (eg, one cell type was very similar to a liver cell type; another was very similar to a white blood cell). This way not only can we see what is similar, we can also see differences between these cell types.

There is a lot more to get to know and understand here - this is definitely closer to the start than the end. But it is a substantial amount of data, and analysis, to start on this journey.

According to the abstract of one of the lead papers from Nature, this extraordinary glut of data “enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions.” Only 2% of the genome codes for proteins, but 80% or more has some biochemical function. As a Science news article put it, these 30 papers “sound the death knell for the idea that our DNA is mostly littered with useless bases.”

The pro-Intelligent Design organization The Discovery Institute has heralded the discovery as the “demise of junk DNA.” Casey Luskin writes for their blog Evolution News:

Let's simply observe that it provides a stunning vindication of the prediction of intelligent design that the genome will turn out to have mass functionality for so-called "junk" DNA. ENCODE researchers use words like "surprising" or "unprecedented." They talk about of how "human DNA is a lot more active than we expected." But under an intelligent design paradigm, none of this is surprising. In fact, it is exactly what ID predicted.

The extent to which the ENCODE project been able to identify function has been surprising—even exhilarating—though scientists have for some time been getting glimpses of the many ways in which segments of DNA can be “active.” Even in 1970 biologists knew that some non-coding DNA had function, and by 2003 there was a large body of work demonstrating that many non-coding elements acted as promoters, enhancers, insulators, and so on. Indeed, in recent years many have come to appreciate the fact that “junk” was never really an appropriate metaphor in the first place. Still, because sequencing of multiple genomes has shed such extraordinary light on key evolutionary mechanisms, many geneticists have focused on function primarily in terms of which regions do or do not contribute to the evolutionary fitness of their host, rather than whether they were merely "doing something" biochemically. What the impressive ENCODE project has done is open a treasure trove of new information that can only accelerate the pace at which researchers are able to explore the incredible subtlety and complexity of DNA, and refine the very concept of “functionality.”

So with all this in mind, is ENCODE a stunning victory for ID, as Luskin believes? Bryan College biologist Todd Wood thinks not. He writes, “I don't think that function equates to design, nor do I think that design requires or predicts function. They're not the same thing… my understanding of function does not require me to hypothesize God (or an anonymous designer, if you must) as the proximal cause.”

We agree. Indeed we would go on to say that evolution and design are not mutually exclusive. So while finding function is not sufficient to prove design, recognizing that function has arisen by way of evolution does not indicate that God was not at work. We at BioLogos believe God providentially works out his purposes—his designs—through the elegant processes of evolution, not in opposition to them.

Amazing as the new data are, it only strengthens and enhances our evidence for evolution. While much of the genome is “doing something” biochemically, it is still likely that the majority of the sequence is evolutionarily neutral (Senior Fellow Dennis Venema discusses the evidence for this “neutrality” in a post on our site, including a striking comparison between 29 different mammal genomes and the human genome). In fact, another ENCODE researcher participating in the Science magazine chat, John A. Stamatoyannopoulos of the University of Washington School of Medicine, thinks the findings align beautifully with evolutionary theory:

ENCODE's data provide a unique and powerful window through which to view evolutionary change. We can see those changes directly by lining up the genome sequences of many different organisms -- these line-ups have revealed millions of regions where all the genomes agree, indicating sequences that have been specially preserved by evolution while others have decayed away (ie freely changed their letter codes). We now see that a large proportion of these 'conserved' regions are lighted up by ENCODE annotations, indicating that they are marking spots in the genome that contain important instructions for cell function.

We’ve discussed “junk” DNA previously, including a multi-part series by Dennis Venema, and we’ve received many emails over the past few days asking for our comments on the ENCODE findings. On Monday and Tuesday, Dr. Venema will begin to offer his own thoughts on ENCODE.

A special thanks goes to Darrel Falk, Mark Sprinkle, Kathryn Applegate, Dennis Venema, and Tom Burnett for their contributions to this post.

In Tennessee and across the country, many others weighed in on the subject over the next few weeks, including two essays (here and here) on the BioLogos Forum. But soon after that, other issues crowded that story off the front page. Now, though, teachers and students across my state are returning to science classrooms, and we will all get to see what effect the law has in practice. Again speaking as a Christian, a biologist, and educator and drawing on all three of those perspectives, I’d like to offer my own reflections on the bill’s likely effect on Tennessee teachers and students, beginning with this excerpt from the bill itself:

The teaching of some scientific subjects, including, but not limited to, biological evolution, the chemical origins of life, global warming, and human cloning, can cause controversy . . . The state board of education, public elementary and secondary school governing authorities, directors of schools, school system administrators, and public elementary and secondary school principals and administrators shall endeavor to assist teachers to find effective ways to present the science curriculum as it addresses scientific controversies. (Tennessee HB368 / SB893)

As an evangelical, I think this bill could be more detrimental than helpful to Christian teenagers’ faith. Many students who are particularly interested in the sciences and theory of evolution are already in the uncomfortable position of hearing pro-Intelligent Design doctrine from the pulpit on Sunday and then listening to their science teacher’s evolution instruction on Monday. I was one of those students—sitting in more than one congregation under pastors who were particularly antagonistic to the theory of evolution, and who made not-so-subtle comments that it cannot co-exist with authentic Christian faith. Having a keen interest in the sciences and wanting to explore the data so widely accepted by the scientific community, I felt confused and ostracized in my church. I wondered if I would have to choose between my faith and intellectual integrity. The church family I trusted clashed with the science that I also trusted, causing a near catastrophe for my faith. I am thankful to the few people who offered me grace, allowing for my questioning of some of what I heard in church without labeling me a heretic.

Though the conservative Christian community may view this bill as a “win for the faith,” it is actually a loss if it reinforces the idea that this is simply an issue of science vs. scripture. Evolution is central to modern biology; trust in the authority of the Scriptures is central to Christian faith. But this fight mentality between the two established communities is detrimental to our young teenagers who are seeking to grow in faith, but who cannot seem to reconcile scripture and scientific data. We need them to seek after that reconciliation, not be told it can’t be done. Whatever they are hearing from the pulpit, the science classroom should be the one place that students can learn science. Students may well emerge with bitterness towards the church for dismissing the evidence of evolution not only so quickly, but in what is so often a haughty and condescending manner. Worse yet, students may emerge with bitterness that they were forced to choose between faith and intellectual integrity. Is this really an all or nothing argument? Are the two truly diametrically opposed?

In my world, these two have reconciled, and they now co-exist in peace. It has been a very long road to get there and I could not have done it without both access to good data and the freedom to explore it. Having taught teenagers in an evangelical church for years and having observed in many biology classrooms as well, I know that many students are still struggling for this same reconciliation. That reconciliation is perhaps most easily attained when the seeking student is able investigate evolution in the science classroom without harassment from opposing religious forces. With this freedom, the student may very well realize that the fear that he/she may have regarding evolution is really just a fear of the unknown, and that it is possible to have intellectual integrity and to praise God for initiating and sustaining the evolutionary process.

In Tennessee’s science classrooms there are surely many teachers who begrudge being told that they must teach evolution, and who are relieved that they can now present it as a controversy and/or allow Intelligent Design as an alternative. They, too, will likely see this law as a “win.” But isn’t public science education is about giving students an accurate picture of the state of science, not about teachers’ philosophical opinions? As has been pointed out before, most Tennessee science teachers have not had the training to teach about religion or philosophy; they have been trained to teach about the basic principles of the biological world.

This bill may be particularly frustrating, then, to teachers who do simply want to teach science. From the many hours I’ve spent in secondary biology classrooms this year, I can say for sure that time is of the essence. Tennessee teachers have barely enough instructional time to cover what students must know to pass the end-of-course biology test required for graduation; they do not have extra time to spend covering material that is not science. I have seen classroom arguments over evolution’s feasibility that ate away precious instruction time and only left a greater rift between the two camps and no doubt, a frustrated teacher. News of the Intelligent Design movement’s success in creating political and legal controversy is misplaced content in the secondary biology classroom.

Furthermore, as it allows teachers to frame biological evolution in terms of “controversy”— something that is a topic for debate—this law will likely not result in students who are more engaged in understanding science, but instead, only in more confusion (and possibly antagonism) in the classroom. Educators welcome debate in many cases because debate encourages critical thinking that leads to “formal thought,” the Holy Grail of Piaget’s Theory of Cognitive Development. But the practice of science is about proposing hypotheses and testing the data, not primarily argumentation. And if the science community is not “debating” evolution, why should high school science students be debating evolution as part of their biology curriculum?

The bill is correct in stating that the purpose of science education is to “inform students about scientific evidence” and “help students develop critical thinking skills necessary to becoming intelligent, productive, and scientifically informed citizens.” I certainly agree, though I question whether it needed to be legislated. Rather, my answer is: “Let’s actually do it!” Before bringing “debate” and “controversy” about scientific theories into the classroom, let’s instead teach our students about sound scientific practice; let’s give them opportunities to learn how to research and to employ the scientific method in everyday life. Let’s focus on teaching them about observing the indicators of climate change, the intricacies of DNA, conservation of ecosystems, and the principles of molecular and cell biology. Let’s give them the tools—specific to science— that help them think critically and work out problems, rather than undermining faith in those very practices and the community of people that uses them every day. Let’s not teach them to live in denial of the ordinary dependability of science, let’s not teach them to distrust scientists who have no interest in “debate,” but want to understand the world God made.

In Tennessee and elsewhere, let’s give both our students and those scientists the grace and support they need to merge authentic faith and intellectual integrity.

In his essay for that series, Jeff Schloss addressed the question of whether animal death is a natural evil, but also noted that such theological considerations aside, death does not actually “drive evolution” in the way most people imagine—especially when they think of violence in the natural world. This more complicated sense of death’s role is partially the result of modern evolutionary science recognizing the importance of cooperation and inter-relation among species, rather than just direct competition. But just as important is the knowledge that evolution is significantly shaped not by the deaths of individual creatures, but by extinction, the loss of species over time. In this post, we explore some aspects of how extinction acts as both a destructive and creative force in evolutionary history, including the evolutionary history of mammals.

Sporadic extinction

Extinction is actually a common feature of life on earth when viewed over long (e.g. geological) timescales. By some estimates, over 99% of the species that have ever lived have gone extinct. One factor that promotes extinction is the fact that evolution does not produce species that are optimally adapted to their environment, but only better adapted than their local competitors. Invasive species testify to this fact: local (endemic) species are not always the best-adapted species for their own environment. Examples abound where species from other environments are actually better-suited to out-compete endemic species. Here in my own province, the invasive Himilayan blackberry (Rubis discolor) easily outcompetes many endemic species. If endemic species were optimally adapted to their environment, this would not be possible, as they would outcompete all exotic species. Instead, exotic species, by chance, might be better adapted to an ecosystem they did not evolve in. These exotics may be capable of eliminating endemic species altogether.

Such an extinction event (of a single species, or perhaps a handful of species) alters the environment of other remaining species in an ecosystem. This, in turn, may influence the ability of some of these remaining species to reproduce compared to other species. For example, the extinction of a competitor might allow a species to increase in population size. Conversely, the extinction of a species that provides a benefit (such as a pollinator) may reduce a species in number. As the ecosystem landscape shifts due to loss of species, new biological opportunities, or niches, might arise. These new niches are then available to support new species to fill them.

Extinction, en masse

One way to appreciate how extinction opens up new niches is to examine mass extinction events – geologically brief periods where large numbers of species go extinct at the same time. Over the history of life on our planet there have been several mass extinction events. The largest such event, at the end of the Permian (~250 million years ago) appears to have been caused, at least in part, by intense volcanic activity over several hundred thousand years. This activity likely shifted CO2 levels and eventually led to a “runaway” greenhouse effect that dramatically raised global temperatures and led to anoxic (i.e. oxygen-depleted) oceans, though the exact contributions of these varied factors remains an area of scientific debate. What appears certain is that during this period environmental changes were too rapid for most species to keep evolutionary pace with, and as a result over 90% of the world’s species alive at that time went extinct. Obviously this represents destruction of biodiversity on an unimaginable scale, and the destructive effects of this event are with us to this day.

Speciation, en masse

This destruction, however, is not the whole story. Following on from the Permian mass extinction, we observe a steady increase in new species. These are species previously unknown in the fossil record. In fact, this pattern (a “radiation” of new species following an extinction event) is the rule, not an exception – we see the same effect after every mass extinction in the fossil record. Extinction is a driving force for novelty.

Perhaps the most famous mass extinction event is the Cretaceous – Paleogene (KPg) extinction, and it too follows this standard pattern. This mass extinction took place 65 million years ago when an asteroid ~10 kilometers in diameter struck the Yucatan peninsula. (Note: this event was formerly known as the Cretaceous – Tertiary (K-T) extinction, but that terminology is in decline within the scientific community). This extinction event is famous since it is the one that eliminated the dinosaurs (with the exception of the ancestors of modern birds). As with the Permian extinction, the elimination of so many species shifted the evolutionary landscape for the remaining species, and the result was a burst of speciation that appears rapid when viewed in geological time. Significantly for our own species, following the KPg extinction event is a burst in mammalian speciation, as small mammals that survived the event diverge and fill niches left empty by the dinosaurs. Without this event, the trajectory of mammalian evolution would certainly look very different.

Clearing the deck, and re-filling the niches

One interesting fact to note is that biological features that make a species resistant to usual, sporadic extinction are not necessarily the same features that will be useful during a mass extinction event. While species are continually under selection at the local level, there is no mechanism for (pre) selection to survive a mass extinction. As such, only species that happen to have the right combination of traits will survive, and often spread widely after a mass extinction. These so-called “disaster species” are usually generalists, and will later be displaced by more specialized species as they arise. As such, where sporadic extinction allows for more gradual turnover in species, mass extinction events are major “resets” of evolution that can radically shift what constitutes “well adapted” in a geological eyeblink. For mammals at the KPg boundary, small body size and an omnivorous diet (including the ability to scavenge detritus) were the “winning” combination of traits that allowed them to survive where larger, more specialized animals (think Tyrannosaurus rex) could not. From this rather humble station, mammals would come to dominate the world’s ecosystems over the coming eons – including a lineage that would someday lead to our own species. Far from only a destructive force, extinction is a powerful mechanism to allow evolutionary innovation, and one that was of significant importance to us.

For further reading:

Meredith, R.W. et al (2011). Impacts of the Cretaceous Terrestrial Revolution and KPg Extinction on Mammal Diversification. Science 334; 521-524.

Fastovsky, D.E. (2005). The Extinction of the Dinosaurs in North America. GSA Today (15); 1052-5173.

Benton, M.J. and Twitchett, R.J. (2003). How to kill (almost) all life: the end-Permian extinction event. TRENDS in Ecology and Evolution (18); 358-365.

Asa Gray

If Thomas Huxley earned the title of "Darwin's bulldog," then Asa Gray should be remembered as "Darwin's dove." Whereas Huxley enjoyed a good fight in his defense of Darwin's theory, Gray sought to mediate and bring sides together around a common understanding of "good science." As Darwin's strongest and most vocal scientific ally in the United States, Gray recognized the scientific importance of Darwin's efforts for the growing professionalism of biological researchers.

But as an orthodox Christian, a Presbyterian firmly devoted to the faith expressed in the Nicene Creed, Gray saw in Darwin's theory both evidence for his philosophical commitment to natural theology and support for his opposition to the idealism advocated by Louis Agassiz and the Naturphilosophen in both Europe and America. Indeed, Agassiz's advocacy of Platonic forms as a basis of biological understanding (e.g., "A species is a thought of the creator")¹ would be a major source of American opposition to Darwin's theory.

Professor of botany at Harvard during most of the middle half of the nineteenth century, Gray was one of the few members of the scientific community to whom Darwin revealed his theory before the publication of On the Origin of Species, and, from what I can tell, the only American. Gray and Darwin met briefly in January 1839 during one of Gray's visits to England. Later, during the 1850s, Darwin wrote Gray on several occasions requesting information--a practice that Darwin frequently employed. In 1854, Darwin's friend and confidant, Joseph Hooker, showed Darwin Gray's review of Hooker's Flora of New Zealand, in which Gray had argued strongly against Louis Agassiz's idealism and had raised questions from his own work on the stability of species. Gray was not yet ready to deny their permanence, but hybrids and other observations were beginning to trouble him.

The next year Gray wrote a lucid and penetrating positive evaluation of Alphonse De Candolle's two-volume Géographie botanique raisonnée, a pioneering work dealing with plant geography and distribution from a statistical perspective. Hooker had sneeringly dismissed the work. In A. Hunter Dupree's authoritative biography of Gray, he describes Gray's puzzlement at Hooker's response in these terms:

Although in the long view Gray's evaluation of the epoch-making nature of De Candolle's book was more justified than Hooker's sneers, [Gray was confused by his response, for] Hooker seemed to be talking with a more comprehensive theory definitely in mind, some reason for taking his position, which he did not divulge and which his friend [Gray] did not possess.²

Darwin, however, saw in both Gray's review of Hooker's book and in his comments on De Candolle's tome that Gray was troubled by some of the same empirical data that had been bothering him. In April 1855, Darwin wrote Gray to urge that Gray update his Manual of the Botany of the Northern United States first published in 1848, and especially to address the issue of the range of Alpine plants in the United States. Specifically, he said: "Now I would say it is your duty to generalise as far as you safely can from your as yet completed work."³

Behind this request was Darwin's desire to test his impression that Gray could make a good ally. Gray passed the test, and finally, in July 1857, Darwin let Gray in on his theory of the transmutation of species. Gray was never an uncritical supporter, and there are many evidences in the correspondence between these two scientists that Gray was willing to challenge Darwin and disagree with some of his conclusions. Nevertheless, Gray saw the importance of Darwin's work and the ways in which it provided answers to the troublesome issues that he had confronted in his own botanical efforts.

Gray responds to Darwin's theory

After considerable interchange--one might even say debate--among Gray, Darwin, and Hooker, Gray wrote to Hooker in October 1859 (one month before the publication of On the Origin of Species) saying that he had absolutely no problem with cognate species arising by variation. He did, however, raise a concern that would be the source of much future discussion. He wondered about Darwin's "carry[ing] out this view to its ultimate and legitimate results,--how [do] you connect the philosophy of religion with the philosophy of your science." He added: "I should feel uneasy if I could not connect them into a consistent whole--i.e., fundamental principles of science should not be in conflict."⁴

When Origins was published, Gray wrote a clear, positive, yet critical review in The American Journal of Science. Aware of mounting religious opposition, he ended his review by arguing that whereas one could use Darwin's theory in support of an atheistic view of Nature, one could use any scientific theory in that way. He wrote: "The theory of gravitation and ... the nebular hypothesis assume a universal and ultimate physical cause, from which the effects in nature must necessarily have resulted."⁵ He did not see the physicists and astronomers who adopted Newton's theories as atheists or pantheists, though Leibniz earlier had raised such reservations. And a similar situation existed with the origin of species by natural selection. Darwin, Gray continued: "merely takes up a particular, proximate cause, or set of such causes, from which, it is argued, the present diversity of species has or may have contingently resulted. The author does not say necessarily resulted."⁶

This far Gray could go with Darwin. But there was a point at which he parted company, and that was the fortuitous randomness of the process that Darwin's theory seemed to imply.

In part 2, Dr. Miles describes Darwin's struggle with the problem of natural evil and design in nature.

Notes

1. Cited in A. Hunter Dupree, Asa Gray: American Botanist, Friend of Darwin (Baltimore: The Johns Hopkins Press, 1959), 151. 2. Ibid., 236.
3. Charles Darwin, More Letters of Charles Darwin, ed. Francis Darwin, (New York: D. Appleton and Company, 1903), 252.
4. Dupree, Asa Gray, 266.
5. Asa Gray, "The Origin of Species" in Darwiniana (Cambridge, MA: The Belknap Press of Harvard University, 1963), 44.
6. Ibid.

But it is also important that we engage believers who disagree with us (on human origins, especially) with charity and humility as a witness to our common identity in Christ—that we may be known by our love for each other in tandem with our demonstrated love for the secular world that does not yet claim Christ as Lord and Savior.

While the BioLogos Foundation is committed to both of these aspects, we are especially pleased that our desire to engage in gracious dialogue with fellow believers who reject biological evolution has been receiving increased and very favorable attention in both the Christian and secular press. More importantly, we are being joined in that reconciling project by those who have often been defined primarily as our “opponents,” rather than as brothers and sisters in Christ.

First, A Tale of Two Scientists, the cover story of Christianity Today’s July-August 2012 issue, featured the accounts of BioLogos Foundation President Darrel Falk and Todd Wood, Director of the Center for Creation Research at Bryan University. Though Wood does not accept biological evolution on theological grounds, both men recognize its strength and explanatory power. But more importantly, both reject the warfare model between science and faith (and between Christians who think differently) as being, in Wood’s words, “detrimental to the Church.”

Second, our Southern Baptist Voices series has become a model for how such dialogue can be pursued, even in the sometimes no-holds-barred context of the web. Several installments in our ongoing dialogue with Southern Baptist theologians have been covered by the Erin Roach of the Baptist Press (on May 25th , June 6th, and July 3rd) and on on July 19th by Lillian Kwan of the Christian Post. And just this past week, Associated Press reporter Travis Loller highlighted the series in an article picked up by the Huffington Post, the Washington Post, and many other news outlets across the country.

To make it easier for readers to find the entire Southern Baptist Voices series and join in the conversation themselves, we’ve launched a new landing page here: Southern Baptist Voices. It is our hope and prayer that this initiative will set the stage for future dialogue between evolutionary creationists and those who hold other perspectives, as well.

There are two opposite errors which need to be countered about the fossil record: 1) that it is so incomplete as to be of no value in interpreting patterns and trends in the history of life, and 2) that it is so good that we should expect a relatively complete record of the details of evolutionary transitions within all or most lineages.

What then is the quality of the fossil record? It can be confidently stated that only a very small fraction of the species that once lived on Earth have been preserved in the rock record and subsequently discovered and described by science.

There is an entire field of scientific research referred to as "taphonomy" -- literally, "the study of death." Taphonomic research includes investigating those processes active from the time of death of an organism until its final burial by sediment. These processes include decomposition, scavenging, mechanical destruction, transportation, and chemical dissolution and alteration. The ways in which the remains of organisms are subsequently mechanically and chemically altered after burial are also examined -- including the various processes of fossilization. Burial and "fossilization" of an organism's remains in no way guarantees its ultimate preservation as a fossil. Processes such as dissolution and recrystallization can remove all record of fossils from the rock. What we collect as fossils are thus the "lucky" organisms that have avoided the wide spectrum of destructive pre- and post-depositional processes arrayed against them.

Soft-bodied organisms, and organisms with non-mineralized skeletons have very little chance of preservation under most environmental conditions. Until the Cambrian nearly all organisms were soft-bodied, and even today the majority of species in marine communities are soft-bodied. The discovery of new soft-bodied fossil localities is always met with great enthusiasm. These localities typically turn up new species with unusual morphologies, and new higher taxa can be erected on the basis of a few specimens! Such localities are also erratically and widely spaced geographically and in geologic time.

Even those organisms with preservable hard parts are unlikely to be preserved under "normal" conditions. Studies of the fate of clam shells in shallow coastal waters reveal that shells are rapidly destroyed by scavenging, boring, chemical dissolution and breakage. Occasional burial during major storm events is one process that favors the incorporation of shells into the sedimentary record, and their ultimate preservation as fossils. Getting terrestrial vertebrate material into the fossil record is even more difficult. The terrestrial environment is a very destructive one: with decomposition and scavenging together with physical and chemical destruction by weathering.

The potential for fossil preservation varies dramatically from environment to environment. Preservation is enhanced under conditions that limit destructive physical and biological processes. Thus marine and fresh water environments with low oxygen levels, high salinities, or relatively high rates of sediment deposition favor preservation. Similarly, in some environments biochemical conditions can favor the early mineralization of skeletons and even soft tissues by a variety of compounds (eg. carbonate, silica, pyrite, and phosphate). The likelihood of preservation is thus highly variable. As a result, the fossil record is biased toward sampling the biota of certain types of environments, and against sampling the biota of others.

In addition to these preservational biases, the erosion, deformation and metamorphism of originally fossiliferous sedimentary rock have eliminated significant portions of the fossil record over geologic time. Furthermore, much of the fossil-bearing sedimentary record is hidden in the subsurface, or located in poorly accessible or little studied geographic areas. For these reasons, of those once-living species actually preserved in the fossil record, only a small portion have been discovered and described by science. However, there is also the promise of continued new and important discovery.

The forces arrayed against fossil preservation also guarantee that the earliest fossils known for a given animal group will always date to some time after that group first evolved. The fossil record always provides only minimum ages for the first appearance of organisms.

Because of the biases of the fossil record, the most abundant and geographically widespread species of hardpart-bearing organisms would tend to be best represented. Also, short-lived species that belonged to rapidly evolving lines of descent are less likely to be preserved than long-lived stable species. Because evolutionary change is probably most rapid within small isolated populations, a detailed species-by-species record of such evolutionary transitions is unlikely to be preserved. Furthermore, capturing such evolutionary events in the fossil record requires the fortuitous sampling of the particular geographic locality where the changes occurred.

Using the model of a branching tree of life, the expectation is for the preservation of isolated branches on an originally very bushy evolutionary tree. A few of these branches (lines of descent) would be fairly complete, while most are reconstructed with only very fragmentary evidence. As a result, the large-scale patterns of evolutionary history can generally be better discerned than the population-by-population or species-by-species transitions. Evolutionary trends over longer periods of time and across greater anatomical transitions can be followed by reconstructing the sequences in which anatomical features were acquired within an evolving branch of the tree of life.

In the last post in this series, we introduced a paper by Chen and colleagues that sought to identify new genes in various Drosophila (fruit fly) species. The youngest (i.e. the most recently evolved) gene they found is one specific to Drosophila melanogaster, the species of fruit fly beloved by geneticists as a model organism. The gene is named “p24-2” (not the most imaginative name, but it serves its purpose) and the gene it is duplicated from is called “Éclair”. The Éclair gene is found in a number of Drosophila species. A simplified “family tree” of three Drosophila species (D. melanogaster, D. simulans and D. erecta) is shown below. The duplication event that generated the p24-2 gene happened within the lineage leading to D. melanogaster, but after D. melanogaster and D. simulans separated as distinct species:

Since the entire genomes of these species are now sequenced and available online, it is possible to look at the chromosome region where the Éclair gene is found in all three. By looking at this region in D. melanogaster, we see that the brand-new p24-2 gene is almost right next door to its “parent” gene, Éclair. Below is a screen shot taken when looking at this region using a Drosophila “genome browser” that is freely available online. The red arrow indicates the Éclair gene, and we can see p24-2 is just one gene over, and seems to be nested within another gene called “Unc-115b”. The green arrows are pointing to two different “versions” of how p24-2 is made into an mRNA working copy. The Unc-115b gene (blue arrow) has five different mRNA versions. (One of the p24-2 mRNA versions has a lot of Unc-115b sequence that is not used when the p24-2 protein is made).

(Click Image to Enlarge)

Finding a duplicated gene next door to the sequence it is copied from is pretty common in genomes – when chromosomes are copied or recombined during cell division, side-by-side copies of parts of chromosomes show up every now and then. It’s also not surprising to see a new gene cobbled together with another gene. In this case, Unc-115b and p24-2 are overlapping but separate functional entities: they each have their own protein sequences, but each includes the code of the other as a sequence that does not actually translate into protein. The details of how this “cobbling” happens aren’t important for this discussion, other than to note that the mechanisms are known and not rare. In the chart above, then, the orange sections indicate the active parts of the transcribed sequence, while the gray are sections that are included in the RNA molecule, but do not get used directly to code for the new protein.

When we look at this same chromosome region in D. simulans and D. erecta, however, p24-2 is missing. Éclair and Unc-115b are there, but p24-2 is not, since it arose after D. melanogaster separated from its common ancestors with the other species. (Note: this entire region is a mirror image in D. simulans and D. erecta when compared to D. melanogaster due to a large scale chromosome inversion that covers this whole area. So, while it looks “backwards” compared to the image above, that is not surprising, it’s expected):

(Click Image to Enlarge)

So, with the p24-2 gene in D. melanogaster, we have a bona-fide, recent gene duplication event. This gene is brand new, evolutionarily speaking (less than 3 million years old, given the calculated speciation times of D. melanogaster and D. simulans). Not only is it brand new, it is also essential for survival in D. melanogaster: if you remove it, the fly dies. Obviously, since every other Drosophila species lacks p24-2, this gene is not essential for survival for any other species. It’s new, and now it’s necessary.

Do new, essential genes refute the Intelligent Design (ID) argument from Irreducible Complexity (IC)?

So far, nothing we have discussed explicitly threatens the ID argument from IC, though it does threaten the ID argument that new information cannot arise through evolution, a topic we have discussed in detail before. Michael Behe, the main ID proponent of the argument from IC, has commented on this research by Chen and colleagues (thanks to commenter “Bilbo” for pointing this out). Behe’s rejoinder was to a blog post by biologist and atheist blogger Jerry Coyne, who used the paper by Chen and colleagues to attack Behe’s ideas. Since Behe’s reply deals with his understanding of how gene duplication relates to his argument from IC, I will quote it here at length:

I have never stated, nor do I think, that gene duplication and diversification cannot happen by Darwinian mechanisms, or that “they play almost no role at all” in the unfolding of life. (As a matter of fact, I discussed several examples of that in my 2007 book The Edge of Evolution. That would be silly — why would anyone with knowledge of basic biochemical mechanisms deny that, say, the two gamma-globin coding regions on human chromosome 11 resulted from the duplication of a single gamma-globin gene and then the alteration of a single codon? What I don’t think can happen is that duplication/ divergence by Darwinian mechanisms can build new, complex interactive molecular machines or pathways. Assuming (since he is in fact critiquing them) Professor Coyne has been attentive to my arguments, one background assumption that he may have left unexpressed is that he thinks the newer duplicated genes discovered by Professor Long’s excellent work represent such complex entities, or parts of them.

There is no reason to think so. A gene can duplicate and diversify without building a new machine or network, or even changing function much. The above example of the two gamma-globin genes shows that duplication does not necessarily result in change in function. The examples of delta- and epsilon-globin, which, like gamma-globin, presumably also resulted from the duplication of an ancestral beta-like globin gene, show that sequence can diversify further, but function remain very similar. Even myoglobin, which shares rather little sequence homology with the other globins, has not diverged much in biochemical function.

In his recent work Professor Long discovered that many of the new genes were essential for the viability of the organism — without the gene product, the fruitflies would die before maturity. Perhaps Professor Coyne thinks that that means the genes necessarily are parts of complex systems, or at least do something fundamentally new. Again, however, there is no reason to think so. The notion of “essential” genes is at best ambiguous. We know of examples of proteins that surely appear necessary, but whose genes are dispensable. The classic example is myoglobin. It is also easy to conceive of a simple route to an “essential” duplicate gene that does little new. Suppose, for example, that some gene was duplicated. Although the duplication caused the organism to express more of the protein than was optimum, subsequent mutations in the promoter or protein sequence of one or both of the copies decreased the total activity of the protein to pre-duplication levels. Now, however, if one of the copies is deleted, there is not enough residual protein activity for the organism to survive. The new copy is now “essential”, although it does nothing that the original did not do.

The main points of Behe’s reply can be summarized as follows:

1. Gene duplications and subsequent changes to the copies (diversification) can and do happen, but the results are nothing really “new”— no new molecular machines or pathways (nor parts of such pathways), nor much in the way of new functions.
2. Duplicated genes can become essential simply by “sharing” the original function, and then reducing their share to a minimum, perhaps through the amount of protein that each copy makes. Again, this is not anything really new, since the copy doesn’t do anything that the original didn’t do already. So, the finding that some gene copies are essential genes is not a threat to the IC argument.

Note that Behe’s reply makes predictions that can be tested with further research. These predictions might be summarized in this way:

1. If IC is correct, duplicated genes will not be part of new, complex molecular pathways or machines.
2. If IC is correct, duplicated genes that are both essential should “share” the original function.

Testing IC with new research

Behe’s reply to the Chen paper is of course hypothetical and speculative – as demonstrated by his own comment that “there is no reason to think” that the duplicated genes are components of new complex pathways or systems. Accordingly, the validity of Behe’s reply depends on its ability to hold up over time as more work is done. Of note, the functions of p24-2 and its parent gene Éclair have been studied intensively since 2010. These studies, as we shall see in the next post in this series, shed quite a bit of light on these questions.

For further reading:

Behe, M.J. Darwin’s Black Box: the Biochemical Challenge to Evolution. Free Press, New York, 1996.

Behe, M.J. The Edge of Evolution: the Search for the Limits of Darwinism. Free Press, New York, 2007.

Chen, S., Zhang, Y, and Long, M (2010). New genes in Drosophila quickly become essential. Science 330; 1682-1685.

I ask the question, “Why is the universe so special?” Now scientists don’t like things to be special; we like things to be general, and our natural anticipation would have been that the universe is just a common or garden specimen of what a universe might be like.

But we’ve come to understand a lot about the history of the universe. We know that our universe started 13.7 billion years ago, and it started extremely simple, just an almost uniformly expanding ball of energy, about the simplest physical system you could possibly think about. But a world that started so simple has of course become rich and complex. With you and me, in fact, the most remarkable and complex consequences are its history, at least of which we are aware. The human brain is far and away the most complicated physical system we have ever encountered anywhere in our exploration of the universe.

That fact itself might suggest that something has been going on in cosmic history rather than just one thing after another. But we’ve also come to understand many of the processes by which this rich fruitfulness has come to birth. As we’ve come to understand these, we’ve come to see that though these processes are of course evolving processes, they took long periods of time – the universe was 10 billion years old before any form of life appeared in it, at least as far as we know anyway – and life of our complexity only appeared yesterday.

Nevertheless, the universe is pregnant with life, pregnant with the possibility of life, essentially from the beginning onwards. By which I mean the given laws of nature had to take a very specific, very finely tuned form, if the universe was to have so fruitful a history.

That’s a very remarkable discovery, and let me give you some examples of why we believe that. If you’re going to have a fruitful universe, one of the first things you have to get right is that you have to have the right stars in the universe. The stars are going to have a very important role to play. First of all, you must have some stars that are going to be very long lived, live for billions of years, steadily burning, steadily producing energy which will enable the development of life on one of the encircling planets. We understand what makes stars burn in that sort of way very well, and it depends on a delicate balance between the strength of gravity and the strength of electromagnetism. Electromagnetism is the force that holds matter together. The seats on which you are sitting are held together by electromagnetism and in fact you are held together by electromagnetism.

If you alter that balance a little bit in one direction the stars will begin to burn intensely, furiously, just pouring out energy and they will only live a few million years rather than a few billion years. If you move it a little bit in the other direction they will burn so slowly they will be brown stars and they will not produce enough energy to fuel the development of life. So you have to have a very delicate finely tuned balance between the strength of gravity and the strength of electromagnetic forces in a fruitful universe.

Remember, science takes the laws of nature, takes the given strengths of gravity, the given strength of electromagnetism, uses that to explain processes in the world, how things happen, but it doesn’t explain where those laws of nature come from. They are just brute facts as far as science is concerned.

And the stars have another absolutely indispensible role to play. The stars are the place where the heavier elements essential for life are made in the interior nuclear furnaces. There are many elements that are necessary for life, of which carbon is perhaps the most essential. Carbon is the basis of the long chain molecules, which are the biochemical basis of life. The early universe only makes the simplest elements; it makes hydrogen and helium and it makes no carbon at all. Carbon only begins to be made when the universe, which started uniform, begins to condense and become lumpy and grainy with stars and galaxies. As the stars condense they heat up, nuclear processes begin again in their interiors. And it’s those nuclear processes in the stars that make carbon and the heavier elements. Every atom of carbon in your body was once inside a star. We are people of stardust made in the ashes of dead stars.

And that’s a very beautiful process that takes place in that sort of way. And one of the great triumphs of astrophysics and the second half of the 20th century was to unravel that process. One of the people who did some of the most important work on that was a senior colleague of mine in Cambridge called Fred Hoyle. And they were trying to figure out how to make carbon. They got helium, and if you can make three helium nuclei stick together that will produce carbon, but when you have something as small as a nucleus it is impossible to get three to stick together at one time, they’re just too small.

Ok, so let’s do it step by step. Stick two together gives you berylium. Helium 4 gives you beryllium-8, hope it stays around for a bit, another helium comes along, attaches itself, and bingo, you’ve got carbon-12. That’s the obvious thing to think about but it doesn’t work in the obvious way, and the reason it doesn’t work in the obvious way is that beryllium-8 is terribly unstable. It doesn’t oblige you by staying around long enough to catch that third helium, at least in an ordinary, straightforward way.

But Fred realized that it would be just possible for this to happen if there was a very large enhancement effect, in the trade we call it resonance, occurring in carbon at just the right energy, it has to be the right energy, which would enable that attachment process to catch that third helium much much more quickly that you might have thought, in fact so quickly that some of them would get caught before the beryllium-8 disappeared. It was a very good idea, and he must have felt pretty pleased with himself and he went off to just check in the nuclear data tables of this particular resonance’s energy levels, and it wasn’t in the tables, but he knew it must be there, he’s carbon based life like you and me.

So he rang up some friends in the States, a father and son team who were good experimentalists and he said, “Look, you missed something. There’s a resonance and energy level in carbon that you haven’t spotted, and I’ll tell you exactly where to look for it. I know exactly where this energy has got to be. You go look for it.” And they said, “No, no, we don’t want to do that, we have more interesting things to do.” But Fred was very determined and he bullied them into looking for it and they found it.

Now that’s a wonderful achievement, to predict an energy level in carbon on the basis of how it might have been made in the stars is a fantastic scientific achievement. But it’s more than that. Fred had a lifetime conviction of atheism, realized of course that if the laws of physics had been just a little bit different that resonance wouldn’t have been there, and the possibility of carbon-based life is too significant for it just to be a happy accident in his view, so he says in a Yorkshire accent that is beyond my power to imitate, he said that the universe is a put-up job. Fred didn’t like the word God, and so he said some Intelligent, capital “I” Intelligence, must have monkied with the laws of nature to make carbon production possible. What that could possibly be I don’t know, but the more sensible thing to say is that creation is ordained, that the laws of nature would be such, as to enable the fruitfulness of carbon-based life.

We’ll come back to evaluating that possibility in a minute, but before we do, let me give you two other examples of how specific, how special, our universe has to be for us to be able to be here today to think about. We live in a universe that is immensely big, beyond our powers to imagine really. There are a hundred thousand million stars in our galaxy in the Milky Way, of which our sun is just a common or garden specimen, and there are about a hundred thousand million galaxies in the observable universe, of which our Milky Way is a pretty common or garden specimen. So we live in a world that is unimaginably vast, and sometimes we might feel upset by that and think, “What could be the significance of us who are simply inhabitants of a speck of cosmic dust, as you might say, in this vast, vast universe?”

Nevertheless, if all those stars were not there, we would not be here to be upset at the thought of them. Because there is a direct connection between how big a universe is and how long it lasts, and a universe that is significantly smaller than our universe would not have been able to last the 14 billion years, which is the necessary time to produce beings of our complexity. So that’s another condition of the world that has to be right for human beings, or something like human beings, to be a possibility.

One final example, which is the finest tuning of all: quantum theory suggests that there should be an energy attached to space itself. In quantum theory the vacuum, so called empty space, is not just a void. There are things called vacuum fluctuations which occur in a continual sort of seething mass of things coming into being and going out of being all the time. So while there is nothing there that doesn’t mean there is nothing happening. That may sound strange and paradoxical but believe me that’s what quantum theory implies. And of course these happenings, these fluctuations, generate a certain amount of energy, we call it “zero point energy”, and that energy is spread out over the whole of space. So we expect there to be energy associated with space.

And just recently the astronomers have discovered something called dark energy which is driving the expansion of the universe, which is just such an energy associated with space. Well that’s very good, you might say. However, when we estimate, just from thinking about quantum theory, how much energy there should be in space it turns out to be a fantastically large amount, and when we see the amount of energy there actually is per volume in space, it turns out to be very, very small in relation to that expected size. In fact, it turns out to be smaller by a factor of 10^-120. That means by a factor of 1 over 1 followed by 120 zeros. You don’t have to be a great mathematician to see that’s a fantastically small number. So some fantastic cancellation has taken place to turn that big number into the tiny number that we actually observe, and if it hadn’t taken place we wouldn’t be here to observe it because significantly higher energy would simply have blown the whole show apart too fast for anything interesting to happen. That’s the finest tuning that we know in the universe: one part in 10¹²⁰.

So we live in a world that is very remarkably finely tuned, and we have to consider that. And all scientists would agree about what I have been telling you; this is non-contentious. Where the contention comes in is what we might make of that, what is the further significance of it.

In the conclusion to Dr. Polkinghorne’s lecture, he looks at two explanations for the "fine-tuning" principle -- the multiverse theory and the existence of a divine intelligence -- and explains why natural theology alone is not sufficient to make the case for a God who interacts and cares for his creation. To make the case for theism, he argues, we need revelation, God's self-disclosure. This is manifest in various ways, including that which we experience personally, including ethics and aesthetics.