"Anyone approaching the Resurrection accounts in the belief that he knows what rising from the dead means will inevitably misunderstand those accounts and will then dismiss them as meaningless" (p. 243).

In fact, if Jesus' Resurrection were "merely" coming back to life in any way that we might comprehend, then it would be of little significance.

"Now it must be acknowledged that if in Jesus' Resurrection we were dealing simply with the miracle of a resuscitated corpse, it would ultimately be of no concern to us" (p. 243).

So what then does Resurrection mean? For Benedict it represents a new dimension of reality breaking through into human experience. It is not a violation of the old; it is the manifestation of something new.

"Jesus had not returned to a normal human life in this world like Lazarus and the others whom Jesus raised from the dead. He has entered upon a different life, a new life -- he has entered the vast breadth of God himself..." (p. 244).

Because it is something entirely new, it cannot represent a violation of natural law as understood by science.

"Naturally there can be no contradiction of clear scientific data. The Resurrection accounts certainly speak of something outside our world of experience. They speak of something new, something unprecedented -- a new dimension of reality that is revealed. What already exists is not called into question. Rather we are told that there is a further dimension, beyond what was previously known. Does that contradict science? Can there really only ever be what there has always been? Can there not be something unexpected, something unimaginable, something new? If there really is a God, is he not able to create a new dimension of human existence, a new dimension of reality altogether?" (p. 246-7)

Thus, in this view, Resurrection (as with all true miracles) is not contrary to science, but an indicator that science does not (yet?) describe the full expanse of reality. Indeed, some may argue that science itself contains similar "indicators." The 11 (or so) dimensional universe required by some versions of string theory, the multiverse theory of the universe where ours is but one of an infinite array of universes with variable physical laws, quantum entanglements, "spooky" action at a distance, the mysterious emergence of consciousness from inorganic matter -- all push the limits of human reason and imagination, suggesting to some that reality may be far more complex than the human mind can grasp.

For a moment, let us entertain the possibility that Resurrection is as Benedict interprets it: not a violation of natural law but an indicator of something beyond our scientific understanding of the universe. This has interesting implications for understanding how believers and skeptics approach the issue. If Resurrection does not violate science, then science does not necessarily constitute an impediment to accepting the reality of Resurrection. If the difference between the skeptic and believer is not science, then is it just a matter of imagination? The believer imagines greater possibilities for the universe than the non-believer. While this is possible, it seems questionable. To my knowledge, no research has found differences in imaginative abilities between religious and non-religious people. Moreover, contrarian examples easily come to mind: Isaac Asimov was an atheist but hardly lacking in imagination when it came to science fiction. I tend to think that both believers and non-believers can imagine (with varying degrees of effort, I'm sure) the new possibilities implied by Resurrection.

Thus, if it is neither imagination nor science that prompts skepticism about Resurrection, then what is left? I suggest that it comes down to a question of authority: At what point does one allow imaginative possibilities to have authority over how one lives? To the believer, Resurrection has an authority that science fiction does not. Resurrection is not thought-provoking entertainment. It requires far more than just imagining greater possibilities for the universe. It requires a change of life, here and now. Unlike the microscopic hidden dimensions of string theory, the new dimension implied by Resurrection has "broken though" into everyday reality and demands a response -- even if that response is to actively ignore it.

Now, what convinces the believer that Resurrection merits such authority when other imaginative possibilities such as extraterrestrial life or time-travel do not? The answer here appears to be historical commitment. There's no record of people committing themselves to the point of martyrdom to other imaginative possibilities as they have to Resurrection. The earliest example of such commitment being found, of course, in the dramatic post-crucifixion turn-around of the Apostles. Such an astounding change of heart, followed by an unwavering commitment capable of altering human history demands a categorically unique explanation: Resurrection.

The believer's argument, however, remains unconvincing to the skeptic. However impressive they might be, a change of heart and steadfast commitment do not necessarily add up to a new dimension of reality. Extraordinary claims require extraordinary evidence. Fair enough. So a key question regarding the interpretation of Resurrection is this: Is the post-crucifixion history of Christianity extraordinary? Does it compel the dispassionate observer to concede that a categorically unique event could plausibly be its best explanation?

It ought to be upon questions such as those above that skeptics and believers respectfully engage one another, rather than the simplistic and often acrimonious sloganeering that has increasingly become the norm.

Understanding John Polkinghorne: Theology of Nature

John Polkinghorne’s interest in natural theology is important, but what really sets him apart from most others is that he combines it with an equally strong interest in theology of nature, which is not the same thing. Where natural theology involves, “metaquestions about the pattern and structure of the physical world,” theology of nature involves, “metaquestions about how its historical process is to be understood.” Rather than “looking to the physical world for hints of God’s existence,” we look “to God’s existence as an aid for understanding why things have developed in the physical world in the manner that they have.” (Belief in God in an Age of Science, p. 13)

On this front, Polkinghorne advances a strongly Christocentric theology of creation, stressing Jürgen Moltmann’s notion of The Crucified God . In the context of Polkinghorne’s theology of nature, the point is that the Creator is the crucified and resurrected second person of the Trinity. Since I devoted a column to this before, I won’t say more here, except to alert readers to the singular importance this particular idea has for him—especially when facing the problem of suffering. “The insight of the Crucified God lies at the very heart of my own Christian belief, indeed of the possibility of such belief in the face of the way the world is.” (Belief in God in an Age of Science, p. 44)

Situating John Polkinghorne: The Resurrection of Jesus

Many Christians today see science as posing dangerous threats to their faith, challenging their understanding of the Bible and undermining core tenets such as the bodily Resurrection of Jesus, the historical basis on which the Christian faith stands or falls. “Evolution” is often identified as the problem, but the real danger is unbridled naturalism. A commitment to naturalistic methods, known as “methodological naturalism,” (MN) has been an integral part of science and medicine since the ancient Greeks. Those methods have been highly successful at producing a coherent, often very convincing picture of nature and the history of nature.

Advocates of Intelligent Design and some other Christians reject MN, but many Christians who work in the sciences and related fields (such as engineering, medicine, or the history and philosophy science) support MN as a properly grounded and properly limited way of understanding reality. In their view, a robust Christian faith is consistent with a commitment to MN, provided that the limits of scientific inquiry are not simply equated with the limits of rationally grounded belief. Polkinghorne fits squarely in this category.

To understand more clearly where Polkinghorne lies on the larger landscape of science and religion, let’s consider his approach to the Resurrection. Many contemporary thinkers, including some theologians and clergy, believe that “science” has somehow made it impossible to believe in the Resurrection, the deity of Jesus, and even belief in the transcendent God of the Bible.

A prime example is John Shelby Spong, a retired Episcopalian bishop whose books have sold more than one million copies. Spong sees the bodily Resurrection as a figment of the disciples’ imaginations, a vestige of a theism that now we must throw away like a threadbare suit of clothes. For Spong, Christians today need to go "beyond theism" throwing out the baby of divine transcendence—the fundamental truth of monotheism—along with the bath water of the credulity and mythology of the pre-modern authors of the Bible and the ecumenical creeds. Spong’s message is that “Christianity must change or die,” and all in the name of “science.”

As Spong likes to say, his work is very controversial, and not just among rank-and-file Christians. Scholars have also railed against him. “I have been attacked in books from the religious right by such people as Alistair MacGrath [whose surname is actually spelled McGrath], N.T. Wright, and Luke Timothy Johnson,” he complains (Why Christianity Must Change or Die, p. xvi).

I understand (with much sadness) that we live in a highly polarized age. Nevertheless, it’s difficult for me to grant much credibility to an author who identifies McGrath, Wright, and Johnson as representatives of the “religious right.” Indeed, if anyone here is distorting the news it is Spong, not they. As the (late) great Catholic biblical scholar Raymond Brown once observed, “I do not think that a single NT [New Testament] author would recognize Spong’s Jesus as the figure being proclaimed or written about.” (Birth of the Messiah, note 321 on p. 704)

Matthias Grünewald, The Resurrection (a wing of the
Isenheim Altarpiece, ca. 1515), Unterlinden Museum,
Colmar, France

Polkinghorne certainly understands science far more than Spong does, and his conclusions about the implications of science for Christian beliefs are markedly different. With respect to the Resurrection, he is basically on the same page with his friend Wright, whose profound book, The Resurrection of the Son of God, he cites with appreciation. Belief in the Resurrection is well supported by the evidence, and the Resurrection, itself, is “the pivot on which the claim of a unique and transcendent significance for Jesus must turn.” Considering authors like Spong (although he does not explicitly name him), he adds, “it would be a serious apologetic mistake if Christian theology thought that operating in the context of science should somehow discourage it from laying proper emphasis on the essential centrality of Christ’s Resurrection, however counterintuitive that belief may seem in the light of mundane expectation.” (Theology in the Context of Science, pp. 135-6)

Amen.

Looking Ahead

This is the Easter season, and I’ll return in a couple of weeks to begin examining Polkinghorne’s approach to the Resurrection more fully, using excerpts from the chapter on “Motivated Belief” from his recent book, Theology in the Context of Science.

References

Raymond E. Brown, Birth of the Messiah: A Commentary on the Infancy Narratives in the Gospels of Matthew and Luke. (1992).

John Polkinghorne, Belief in God in an Age of Science (1998).

John Polkinghorne, Theology in the Context of Science (2009). My review for First Things online is here.

John Shelby Spong, Why Christianity Must Change or Die (1998).

Like any theory, Darwin’s idea that evolution proceeds through natural selection was once merely a hypothesis. In this post, we’ll look at some of the early observations Darwin made on biogeography: the study of where species are distributed across the globe. These lines of evidence would later prod him to consider the possibility that species arise through a natural process of gradual change over time, rather than being independently created in each location where they are found.

The curious case of the missing mammals

As a widely-travelled naturalist on the HMS Beagle, Darwin studied a large number of different environments and documented the species he found in each. The Beagle, engaged as it was in an effort to map the coastline of South America, naturally paid call to numerous island groups along the way, including islands at a great distance from a continent (i.e.oceanic islands). One observation that Darwin made about oceanic islands is that none that he studied had terrestrial mammals on them. Later work, after his voyage, would confirm that this was a general rule. Oceanic islands lack terrestrial mammal species, except for small species that were introduced by humans. In contrast, flying mammals (i.e. bats) were found on oceanic islands, and often these species were endemic (i.e. found nowhere else in the world but the island in question).

Darwin found these observations difficult to square with his (then) working assumption that species were independently created in (and specifically created for) the locations in which they are found across the globe. He discusses these observations, and the questions they raised in his mind, in two chapters entitled “Geographical Distribution” in his Origin of Species. After discussing the similar case that amphibians (such as frogs, newts, and so on) are also not to be found on oceanic islands, he turns his attention to the missing mammals:

Mammals offer another and similar case. I have carefully searched the oldest voyages, but have not finished my search; as yet I have not found a single instance, free from doubt, of a terrestrial mammal (excluding domesticated animals kept by the natives) inhabiting an island situated above 300 miles from a continent or great continental island.... It cannot be said, on the ordinary view of creation, that there has not been time for the creation of mammals; many volcanic islands are sufficiently ancient, as shown by the stupendous degradation which they have suffered and by their tertiary strata: there has also been time for the production of endemic species belonging to other classes; and on continents it is thought that mammals appear and disappear at a quicker rate than other and lower animals. Though terrestrial mammals do not occur on oceanic islands, aërial mammals do occur on almost every island. New Zealand possesses two bats found nowhere else in the world: Norfolk Island, the Viti Archipelago, the Bonin Islands, the Caroline and Marianne Archipelagoes, and Mauritius, all possess their peculiar bats. Why, it may be asked, has the supposed creative force produced bats and no other mammals on remote islands? On my view this question can easily be answered; for no terrestrial mammal can be transported across a wide space of sea, but bats can fly across. Bats have been seen wandering by day far over the Atlantic Ocean; and two North American species either regularly or occasionally visit Bermuda, at the distance of 600 miles from the mainland. I hear from Mr. Tomes, who has specially studied this family, that many of the same species have enormous ranges, and are found on continents and on far distant islands. Hence we have only to suppose that such wandering species have been modified through natural selection in their new homes in relation to their new position, and we can understand the presence of endemic bats on islands, with the absence of all terrestrial mammals.

(As an aside, it’s important to note that Darwin, when he discusses the “supposed creative force” is not here arguing against the existence of God as creator in general, but rather against the “ordinary view of creation” common at the time: that God had episodically created species at specific geographical locations (what were called “centers of creation”) and that biogeographical patterns could be explained with limited dispersal from those centers. Darwin himself held to this common view at the start of his voyage on the Beagle, and that is the model he is attempting to refute in Origin, since it was a prevailing view among scientists at the time. Darwin and many of his scientific contemporaries also had no difficulty viewing natural processes as part of God’s regular action in the world, as is evident in Darwin’s correspondence with American botanist Asa Gray, among others.)

So, for Darwin, his biogeographical observations sat at ease with his (later) ideas of colonization and subsequent species change through natural selection, but made no sense to him if one held to an independent creation model. Many oceanic islands were very old, yet no mammals had been created there. Many oceanic islands had habitat suitable for mammals (or, indeed, for amphibians, as he notes) yet no such species had been created for that suitable habitat.

Island endemics and their continental “allied species”

Darwin noticed more than the absence of certain species groups on oceanic islands. He also noticed an interesting feature of the species that were present: an endemic species on an oceanic island would often have strong similarities with a species on the mainland closest to the island in question. Additionally, the pairing of oceanic endemic species with continental species often seemed to override expectations that species found in similar environments would be more similar to each other. These observations prompted him to reflect further on the possible means by which these “closely allied species” arose. As Darwin would write in his Origin this repeated pattern made a significant impression on him, and further caused him to doubt that endemic species had been individually created for each oceanic island. His visit to the Galapagos would prove instrumental on this point:

The most striking and important fact for us in regard to the inhabitants of islands, is their affinity to those of the nearest mainland, without being actually the same species. Numerous instances could be given of this fact. I will give only one, that of the Galapagos Archipelago, situated under the equator, between 500 and 600 miles from the shores of South America. Here almost every product of the land and water bears the unmistakeable stamp of the American continent. There are twenty-six land birds, and twenty-five of these are ranked by Mr. Gould as distinct species, supposed to have been created here; yet the close affinity of most of these birds to American species in every character, in their habits, gestures, and tones of voice, was manifest. So it is with the other animals, and with nearly all the plants, as shown by Dr. Hooker in his admirable memoir on the Flora of this archipelago. The naturalist, looking at the inhabitants of these volcanic islands in the Pacific, distant several hundred miles from the continent, yet feels that he is standing on American land. Why should this be so? why should the species which are supposed to have been created in the Galapagos Archipelago, and nowhere else, bear so plain a stamp of affinity to those created in America? There is nothing in the conditions of life, in the geological nature of the islands, in their height or climate, or in the proportions in which the several classes are associated together, which resembles closely the conditions of the South American coast: in fact there is a considerable dissimilarity in all these respects. On the other hand, there is a considerable degree of resemblance in the volcanic nature of the soil, in climate, height, and size of the islands, between the Galapagos and Cape de Verde Archipelagos: but what an entire and absolute difference in their inhabitants! The inhabitants of the Cape de Verde Islands are related to those of Africa, like those of the Galapagos to America. I believe this grand fact can receive no sort of explanation on the ordinary view of independent creation; whereas on the view here maintained, it is obvious that the Galapagos Islands would be likely to receive colonists, whether by occasional means of transport or by formerly continuous land, from America; and the Cape de Verde Islands from Africa; and that such colonists would be liable to modification;—the principle of inheritance still betraying their original birthplace.

Many analogous facts could be given: indeed it is an almost universal rule that the endemic productions of islands are related to those of the nearest continent, or of other near islands.

Rethinking independent creation

For Darwin, both of these observations (that oceanic islands lacked terrestrial mammals, and that endemic species on islands were most similar to a species on the closest mainland) had the same explanation: his hypothesis that endemic, oceanic species were the modified descendants of a colonizing species from the nearest continent. This also explained the lack of amphibians and terrestrial mammals (but allowed for bats) - simply based on the ability of these classes of life to disperse across large expanses of ocean. Those that could disperse and colonize oceanic islands would experience modification in the new environment, and species unable to colonize these islands would never appear. To Darwin’s thinking, this explanation was wholly more satisfactory than the assumption that God had independently created every endemic species in its place, and arbitrarily chosen that oceanic islands did not need terrestrial mammals and amphibians.

Despite Darwin’s musing on the biogeographical patterns he observed, and the strong suggestion these patterns made of species change over time, a mechanism for that change would take some time for him to imagine. In our next post, we’ll look at that mechanism: Darwin’s idea of natural selection, and the evidence he assembled in its support prior to publishing the Origin.

Grantees will benefit from in-person interaction through a series of summer workshops in 2013, 2014, and 2015. These meetings will not only foster a broader knowledge base, but will build a sustained network of scholars and church leaders, both young and seasoned, who are serious about addressing the concerns of the church about evolution. Also in 2015, in connection with the third summer workshop, BioLogos will host a large conference open to scientists, scholars, and church leaders from around the world.

ECF History

In January 2012, BioLogos was awarded a multi-million dollar grant from the John Templeton Foundation to fund the work of scholars and church leaders on evolution and Christian faith. In spring 2012 we worked hard to get the word out. You may have seen announcements on the BioLogos website, in our newsletters, on the Books & Culture, Leadership Journal, or First Things websites, on your professional society’s listserv, or perhaps on your friend’s blog.

The response was overwhelming: we received 225 letters of intent for a total request of $21 million—about seven times the amount we had to offer. We needed to invite the most promising applicants to submit a full proposal, but recognizing the projects with highest potential would require broad expertise. From the beginning, we envisioned that a panel of scientists, pastors, and scholars would oversee the application and review process as well as play key advisory roles throughout the project. A team of eight highly qualified individuals came on board in the early months of the project. They reviewed each proposal and together recommended that BioLogos invite 86 applicants to submit full applications.

The deadline for submissions was October 1, 2012. As in the previous round, the ECF panel evaluated each proposal. In addition, we asked 55 other experts to participate, so that each proposal received 3-4 scores. Criteria for the decision included significance of topic, project design, creativity and innovation, long-term impact potential, feasibility, and budget.

The panel then met together November 29-30, 2012, to make the final funding decisions. In the end, they recommended that BioLogos give 37 awards, ranging from $23,000 to $300,000. BioLogos staff notified applicants of their awards on December 14, 2013.

The Grantees

As part of our objective to create a network of scholars and leaders, we awarded grants to organizations across the U.S. and the world. Thirty of the 37 grantees are domestic; seven are international, hailing from Canada, France, Great Britain, Netherlands, and Spain.

Two-thirds of the accepted projects will be led by teams—some with three or more Project Leaders. We expect that the teamwork and time spent together at our summer workshops will be the start of a long-lasting network of people dedicated to helping the church think carefully about origins.

Applicants chose to apply under one of three program tracks: interdisciplinary scholarship (Track 1), intra-disciplinary scholarship (Track 2), and translational projects (Track 3). Track 1 projects focus on both the collaboration between individuals in different disciplines and the development of projects at the interface of different content areas. Track 2 projects focus on work done within a specific discipline. Track 3 focuses on projects that encourage Christians, especially those within more conservative traditions, to engage in meaningful and productive dialogue to reduce tensions between mainstream science and the Christian faith. The numbers of grantees in Tracks 1, 2, and 3 are 6, 8, and 23, respectively.

Many of the scholarly projects tackle questions about Adam and Eve, the Fall, human identity, and Original Sin—some of the most critical interpretive issues for evangelical theology.  Some examples: 

• Theologian Oliver Crisp of Fuller Seminary will take an analytic theology approach to ask to what extent a theological account of the origin of human sin depends upon the evolution of modern humans from one and only one ancestral pair—especially if that pair does not appear to correspond to what we would think of as modern human beings. 

• Pastor Michael Gulker and philosopher James Smith, leading a large team from The Colossian Forum, ask a related question: if humanity emerged from non-human primates—as genetic, biological, and archaeological evidence seems to suggest—then what are the implications for Christian theology’s traditional account of origins, including both the origin of humanity and the origin of sin? 

• Biologist Dennis Venema of Trinity Western University and New Testament scholar Scot McKnight of Northern Seminary will write a book on the evidence for evolution and population genetics, with informed theological reflection on how these issues interact with orthodox Christianity.

• Biologist David Wilcox of Eastern University will develop an updated model of human identity which reflects the complex recent scientific advances in genetics and paleoanthropology and yet is sensitive to theological concerns.  

These are just a few of the scholarly awards; check out the Grantees page for full descriptions of all Track 1 and Track 2 projects.

All projects have translational potential, but Track 3 projects are designed to meet the needs of a particular constituency within the evangelical church. These projects run the gamut from ethics to education to media production to ministry resources.  Some examples include:

• Theologian Lee Camp of Lipscomb University will produce “The Questions in Monkey Town,” an episode of Tokens, a live variety show that features musical performances, comedic sketches, brief interpretive monologues, and dialog with authors and scholars. The episode will be performed and filmed on the site of the famous Scopes Trial in Dayton, Tennessee.

• Chaplain Joshua Hayashi and Educator Diane Sweeney of the Punahou School in Hawaii will lead a team to produce multimedia curricula aimed at helping high school students connect with their biology curricula and, at the same time, deepen their Christian faith.

• Physics teacher and pastor Benoît Hébert of Science et Foi Chrétienne in France will lead an international, multi-denominational team of French speaking Evangelical scientists, pastors and church leaders to produce a large number of resources on evolutionary creation.

• Pastor Seung-Hwan Kim of Grace Truth Community Church, a Southern Baptist church in Cambridge, Massachusetts, will produce teaching and preaching materials about evolution for church leaders.

• President Gregory Wolfe and Director of Resource Development for IMAGE will gather artists and writers of faith whose work explores the dialogue between evolutionary science and faith practice, convening a conversation between them and scientists, theologians, and church leaders in private and public conferences.

Again, this is just a taste of the diversity of Track 3 projects. Read more about each project on the Grantees page. You can look forward to an incredible variety of resources coming out of the ECF program, many of which will be featured right here on the BioLogos Forum.

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.

Tonight and tomorrow, Christians around the world stop to remember and celebrate the birth of Jesus in Bethlehem just over two thousand years ago. The familiar narrative of Joseph leading Mary to the stable to give birth to the Messiah, of the angels telling the shepherds in the fields of the great event that was happening nearby, and of the three men from the east who came to pay homage to the new King of Israel is re-told or acted out in countless churches, schools and homes. And from countless pulpits, the message goes out that those events are not just a quaint story and an excuse to give gifts, but the central mystery of our faith—that God himself became one of us in order to redeem us and the cosmos from our bondage to sin and death. That mystery—that the Creator God is also the Redeemer Christ—has been to focus of our worship since the first days of the church, and is the subject of the 7th-century Latin hymn Conditor alme siderum, presented here in a new setting from Alex Mejias and High Street Hymns.

While this recording includes only verses one and three from the original text (given in full below), it adds a refrain that catches the spirit of the whole hymn and emphasizes the longing we still feel even in our Christmas joy—the “already, but not yet” state in which we find ourselves today, living between that first Advent and the second Advent yet to be: “Come, O come to us!” For while we know that God has come to us in Jesus—that his death and resurrection have redeemed us and the universe—we are still waiting for that final consummation, depending on the Spirit to be working out our salvation even now. Until the time when, as the hymn says, “all hearts must bow,” the entire BioLogos community invites you to join us in the blessed work of declaring, celebrating, and following the Christ who is both Creator and Savior.

Creator of the Stars at Night

Alex Mejias is the founder and director of High Street Hymns, a non-profit music ministry that exists to spread the Gospel and worship the Triune God in spirit and truth through hymns, psalms and spiritual songs. Alex grew up in New Jersey and outside Washington, DC, receiving a BA in Religious Studies from the University of Virginia and a J.D. from the University of Virginia School of Law. For the past 15 years he has been leading worship for churches and ministries, writing and recording both new and old hymns, and touring the east coast as a singer-songwriter. Alex is also committed to the power of the creative arts to advance the Gospel and promote justice and healing in the name of Christ, serving, supporting, and collaborating with several other non-profit ministries.

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.

The Denisovans, an extinct hominid group that interbred with modern humans, made the news again lately with the publication of a more detailed study of their genome. One of the many interesting findings was that the Denisovans share the same chromosome 2 fusion that modern humans have. In this post, I review what we know about the origins of human chromosome 2, and then discuss the new Denisovan findings and their implications.

The origins of human chromosome 2: a brief review

Though I have discussed the evidence for a fusion event leading to human chromosome 2 before, perhaps a brief review of the evidence is in order. The human genome is made up of 23 pairs of chromosomes (for a total of 46 chromosomes). This makes us something of an oddity among living great apes, all the rest of whom have 24 pairs of chromosomes (for a total of 48). Given that there are many independent lines of evidence that support the conclusion that we share a common ancestor with other great apes, this poses something of a conundrum: how is it that our species arrived at this specific chromosome number? If we were to represent this “problem” on a phylogeny, or tree of relatedness, it would look something like this (not to scale):

Our closest living relatives, chimpanzees and bonobos, both have 48 chromosomes, as do all other great apes such as gorillas and orangutans. This pattern has one of two explanations, one of which is much more likely than the other. Either the common ancestor to these species had 48 chromosomes, and there was an event that reduced that number to 46 specifically on the lineage leading to humans (option A), or the common ancestor species had 46 chromosomes, and there were independent, repeated events that increased chromosome number in all other great ape species (option B). We can compare these options by placing the required event(s) on the phylogeny (again, not to scale):

It should be obvious that the option that requires the fewest events is the more likely one – in this case option A with an event that reduces chromosome number in the lineage leading to humans. The other option, that of repeated, independent events to increase chromosome number, remains a formal, but unlikely, possibility. Events that reduce chromosome number are not frequent occurrences, so Option A is more likely than Option B.

We can also find further support for Option A, because it predicts a specific type of event, namely one that reduces chromosome number. Since loss of a large amount of chromosomal material is almost always detrimental, we need an event that reduces chromosome number without losing information. One way for this to happen is for two chromosomes to fuse together and become one. Initially, this event would produce an individual with 47 chromosomes, where two different chromosomes get stuck together. Contrary to what is often assumed, this individual would be fertile and able to interbreed with the others in his or her population (who continue to have 48 chromosomes). In a small population, over time, two relatives who both have one copy of the fusion chromosome may mate and produce some progeny with two copies of the fused chromosome, or the first individuals with 46 chromosomes. Since either a 48-pair set or a 46-pair set is preferable for ease of cell division, this population will either eventually get rid of the fusion variant (the most likely outcome), or by chance will switch over completely to the “new” form, with everyone bearing 46 chromosome pairs. While not overly likely, this type of event is not especially rare in mammals, and we have observed this sort of thing happening within recorded human history in other species. Some mammalian species even maintain distinct populations in the wild with differing chromosome numbers due to fusions, and these populations retain the ability to interbreed.

Further evidence for a fusion event in the lineage leading to modern humans comes from comparing synteny, or gene locations and orders on chromosomes within modern great apes – an issue we have discussed here before. In brief, what we see in human chromosome 2 is exactly what we would predict for a fusion event. When compared to other great apes, we see the genes on human chromosome 2 match up, in order, with two smaller ape chromosomes. We also see that sequences used at the tips of chromosomes are present at the proposed fusion site, and that human chromosome 2 has not one but two sites for the cell cytoskeleton to attach to for cell division – but that one of the sites is mutated and not functional, though it lines up precisely with the location of this site on the appropriate ape chromosome. Together, this evidence consistently supports both common ancestry for humans and great apes, and specifically that the difference we see in our chromosome numbers arose due to a single fusion event. I briefly discussed this evidence in my last post where I describe how I teach some of this material and the compelling impact it has on students exploring the evolution question for the first time.

Enter the Denisovans

With that as background, we are now prepared to appreciate a new finding that comes from genomics work done on the Denisovan hominids, an archaic species that is more closely related to Neanderthals than to us, but that nonetheless interbred with some anatomically modern humans as they migrated out of Africa and populated the globe. (For those not familiar with the Denisovans, or the evidence for our interbreeding with them, both Darrel Falk and I have written on this previously, here and here). Recently, a more detailed understanding of the Denisovan genome was published, and nested in the new information is the discovery that the Denisovans share the 46 chromosome set with the same fusion that we have. This strongly supports the hypothesis that the fusion event predates the separation of our species. If we were to represent this on a phylogeny, we can now place this event with more accuracy than before (as before, the phylogeny is not to scale):

Despite this new information, one obvious question remains. Did the Neanderthals also have the 46-pair set? From looking at the phylogeny above, we can see that the most likely answer is that they did, since the fact that the Denisovans had it strongly implies that the last common ancestor of humans and Neanderthals / Denisovans had it as well, and the Neanderthal-Denisovan split comes later. While the Denisovan DNA samples are of high enough quality to make this assessment, we do not yet have Neanderthal DNA of high enough quality to do the same analysis with current methods (though one additional feature of the new work on the Denisovan genome is developing more sensitive DNA sequencing techniques that may resolve this question in the future).

In other words, this fusion seems to be an ancient one, predating our species by several hundred thousand years. Present estimates of the last common ancestor between humans and Neanderthals / Denisovans range at about 800,000 years ago.

Implications for understanding our “becoming human”

The main implication from this work is that it places the fusion event well before the advent of our species. I’ve often chatted informally with Christians about evolution, and at times some have thought that this fusion event was what “started” our species, or made our species unable to interbreed with other groups. Some have even suggested that perhaps the fusion event was what produced the first human (i.e. Adam).

Note that thinking this way suggests a misunderstanding of how chromosome fusions occur and what effect they have on their hosts. A fusion does not precipitate a speciation event, but rather the individual with the fusion remains a part of his or her population, and able to interbreed, even if with reduced fertility. Also, there is no necessary biological effect or change that the fusion produces on the appearance of the organism. These misunderstandings aside, however,what this new evidence shows is that this fusion event took place long before modern humans arose at around 200,000 years ago. Indeed, the 800,000 years ago date for the last human - Denisovan common ancestor means that this is the most recent date possible for the fusion. While it is an interesting piece of our evolutionary history, it doesn’t seem to have much to do with how we came to acquire the traits that set us apart from, and ultimately outcompete, other similar species.

Keeping History Safe

In the cold morning air with the sun not yet over the ridge, the place to begin preparation for summiting Mount Darwin is to ponder the reasonableness of miracles. Many Totalizers would like to ban miracles from university consideration and inquiry. Trouble is: human history is awash with credible people reporting miracles.

Modern academic tradition tends to try and maintain order. For historians it behooves us professionally to avoid accounts of alleged spiritual events. We find comfort in a little logical gymnastics that keeps history safe for us to wander in, a deceptively formulaic avoidance method that helps us avoid what people are telling us about extraordinary events in the past.

David Hume popularly articulated this logical gymnastics in an essay titled “Of Miracles” that was eventually printed in Enquires Concerning Human Understanding (1748). “I flatter myself,” Hume triumphantly proclaimed, “that I have discovered an argument . . . which, if just, will, with the wise and learned, be an everlasting check to all kinds of superstitious delusion, and consequently, will be useful as long as the world endures.”

His everlasting check on superstition begins with a circular argument that because miracles can’t happen, a reasonable person should not even listen to reports of them. Hume taught that though the normal job of a historian was to listen to the testimony that comes down to us from the past, there is a point at which you can close your ears. Hume knew that historical testimony can get wild, so he came up with a way to domesticate the wildness, a way to make history a zoo rather than allow it to be a jungle. His “Of Miracles” has been tremendously influential in the discipline of human history over the last two hundred and fifty years, not because his ideas are strong, but because his ideas are useful. Get rid of “superstitious delusions,” and the discipline of history can be turned from a safari into a form of home economics. Hume’s domestication of history is seductively simple. Instead of following the Aristotelian tradition of linking the credibility of hard-to-believe testimony to the credibility of the testifier, Hume recommended disregarding the testifier and focusing only on the testimony. This effectively removed the persuasive power from hard-to-believe testimony. Miracles need the credibility of an eyewitness in order to have persuasive power. Hume cut the power source from the unwanted testimony.

Essentially, Hume adopted the modeling technique that Darwin later used and is best seen in Global Positioning System (GPS) units. Hume recommended gathering testimony from the past and every region to create a general model of what humans generally experience. Using this mass of information, one should generalize standards of common experience. Now if anyone reports a miracle, the alleged event can’t be true because it does not conform to the generalized standards of common experience. (Of course, Hume had already refused to allow that any reports of miracles could be used even to generalize common experience.) It’s tricky. Its logic is circular. But it works to weed out awkward, quirky information. It is as if a domineering GPS unit created a sphere to serve as an abstraction for the earth, then insisted that the earth can’t have wobbling poles and flattening in the upper latitudes because the sphere in the GPS shows it can’t be true. Given a useful and trustworthy GPS, don’t listen to a scientist who might tell you something different than what the GPS tells you.

The circularity of this argument has been noted ever since Hume first proposed it, but Hume was a good writer and said what a lot of people wanted to hear. Miracles are impossible so miracle reports can’t be true. Don’t even listen to reports of them.

Balancing Likelihoods

Also embedded in Hume’s essay is the awkward “rule of logic,” most often called “Balancing Likelihoods.” By combining math and logic in an odd way, Hume’s “Of Miracles “ offered another way for historians to avoid thinking about miracles. Balancing Likelihoods has many names but is probably best stated by David Hackett Fischer, in his Historians’ Fallacies: Toward a Logic of Historical Thought, as “the rule of probability:”

“[A]ll inferences from empirical evidence are probabilistic. It is not, therefore, sufficient to demonstrate merely that A was possibly the case. A historian must determine, as best he can, the probability of A in relation to the probability of alternatives. In the same fashion he cannot disprove A by demonstrating that not-A was possible, but only by demonstrating that not-A was more probable than A. This is the rule of probability.”

This seems to be practical but is impossible. Balancing Likelihoods, in the way described by Fischer, cannot be used by historians in any normal practice. It is a talisman to keep history mentally safe from the wildness that is reported to exist. Logicians, especially mathematicians, have long criticized intellectual constructions like this. The “probability” that Fischer writes about is seemingly mathematical, but the math is simply implied to give a sense of strength to human feelings.

Before Hume wrote “Of Miracles” probabilistic logic had been advancing rapidly and there was a great hope that mathematical analogies would strengthen human thinking—even Christian apologetics. “Pascal’s Wager,” the most famous mathematical apologetic from the seventeenth century, equated eternal salvation with mathematical infinity and then applied it to a gambling formula. Antoine Arnauld, in The Port-Royal Logic (1662), and John Locke, in his Essay Concerning Human Understanding (1690) and Discourse on Miracles (1706), carried probabilistic math and logic into the handling of reported miracles. A half-century later, however, Hume reacted against Arnauld and Locke’s teachings that mathematical analogies could help in the discussion of the credibility of miracles. Hume insisted that to handle a reported miracle, a historian had to create two separate ratios, pro and con, for believability. The ratios were then to be weighed against each other. This is Fischer’s “rule of probability” quoted above. In the language of Hume’s era, this was proclaimed as the “calculus of good sense.”

Lorraine Daston, in Classical Probability in the Enlightenment (1988), offers an excellent study of Hume and the many eighteenth-century mathematicians who wanted to help bring rigorous quantitative thinking to what today would be called the humanities. Daston writes that by the 1840s, mathematicians realized that “the ‘calculus of good sense’ had become antithetical to good sense,” and that today most of what these early probabilists were trying to do is considered “patently absurd.”

In 1901, one of America’s preeminent philosopher-mathematician-logicians, Charles Sanders Peirce, wrote three essays attacking the way historians had adopted Hume’s bad logic: “A Preliminary Chapter, Toward an Examination of Hume’s Argument Against Miracles, in its Logic and in its History,” “Hume’s Arguments Against Miracles, and the Idea of Natural Law,” and “On the Logic of Drawing History from Ancient Documents especially from Testimonies.” Peirce showed that historians are in error when they talk of judging testimony by balancing probabilities because “in a scientific sense, there are no ‘probabilities’ to be judged.”

Probability, Peirce wrote, “is the ratio of the frequency of occurrence of a specific event to a generic event.” A testimony “is neither a specific event, nor a generic event, but an individual event.” Peirce further pointed out that what people were justifying by claiming Balancing Likelihoods was really simply relating “what they prefer to do” to what they don’t prefer. “Likelihood is merely a reflection of our preconceived ideas.”

Historians like me who teach in universities about the reasonable credibility of Jesus’ resurrection need to be students of Peirce not Hume on the subject of assessing the credibility of reports that come down to us from ancient history. Dealing wisely with reports of events verging on the incredible is just part of the normal job of being grounded in the social study of our complex human past.

“Come to history as a doubter,” Richard Marius advises in a historical methods manual. “Skepticism is one of the historian’s finest qualities. Historians don’t trust their sources. . . . Nothing is quite so destructive to a historian’s reputation as to present conclusions that prove gullibility.”

But Marius is wrong. In practice, historians have to trust more than doubt. In practice, historians, especially ancient historians, can’t rely on doubting. Historians have to be close listeners, discerning listeners, wise listeners, who sometimes have to make harmonies and stretch for belief.

There are several different kinds of arguments that people bring along these lines; I want to talk about just one. So first… the Heidelberg catechism, one of the forms of unity of the church I go to (the Christian Reformed Church), says

Providence is the almighty and ever-present power of God, by which he upholds as with his hand heaven and Earth and all creatures and so rules them, that leaf and blade, rain and drought, fruitful and lean years, food and drink, health and sickness, prosperity and poverty. All things, in fact, come to us not by chance, but from his fatherly hand.

And part of the way it comes to us—not by chance, but from his fatherly hand—part of the way God has designed our world, is that there is a great deal of regularity and dependability in our world. Of course, if it were not for this regularity and dependability, we couldn’t do the things that we actually do. I mean, for example, if I just wanted to walk off the stage—if, for example, all the sudden those stairs over there suddenly turned into a ladder going up—well, that would make it really difficult.

If you are trying to build a house, for example, you have this hammer, but all the sudden the hammer turns in to a goose or a pigeon. Again, that would make things really difficult…or if the nail turned into a worm…or if you get in the car and turn the key and the car turns into a camel, things would be really hard, much harder than they are. This regularity and dependability in our world is an essential condition of our being able to live in the world in which we actually do.

If the world were irregular enough, we would not even be able to live in it, but there are also, according to classical Christianity here (the Heidelberg catechism, for example) there are also special divine actions; sometimes God does things specially. There are miracles in Scripture: the parting of the Red Sea, for example, Jesus walking on water, Jesus changing water into wine. There are miraculous healings: Jesus rising from the dead, Jesus raising Lazarus from the dead, and so on. And according to classical Christians, many of them, perhaps most of them, are special divine actions. God, for example, responds to prayers. He works in the hearts and minds of his children to effect sanctification. There is, what Calvin called, the internal testimony or witness of the Holy Spirit, and there is what Thomas Aquinas called the internal instigation of the Holy Spirit. So, these things are all special actions on the part of God. God constantly causes events in the world. Ok, so far fair enough—what is the problem?

Many theologians seem to think there is a science-religion problem here. I don’t think any of the theologians of Biola think this, (I don’t know, but I doubt it) but many theologians do. For example, Rudolf Bultmann says, “The historical method,” which of course he thinks that is the method we should use, “includes the presupposition that history is a unity in the sense of a closed continuum of effects in which individual events are connected by the succession of cause and effect. This continuum, furthermore, cannot be rent by the interference of supernatural, transcendent powers.”

That’s what he says. Alright, there is this continuum that cannot be rent by the interference of supernatural (that would be God) or transcendent powers. So, it is a little bit like the laws of the Medes and Persians. You probably remember Daniel. Daniel was a favorite of King Darius, and well, the other courtiers became jealous of Daniel (they didn’t like it that the king liked him so well). So, they came to the king and said, “Oh king, live forever, we think it would be a great idea if you passed an edict to the effect that you alone can be worshipped. Everybody has to worship you and nothing else.” Well the king thought that over for a minute, and that sounded pretty good to him so he said, “I guess that it is a pretty good idea.” So he made this edict; he made this declaration: “Only King Darius is to be worshipped—no one else, nothing else.”

These courtiers knew that Daniel worshipped God, and they thought probably Daniel would keep right on worshipping God despite this edict. So they were watching Daniel, and he was, in fact, worshipping God. So they came to the king. Now the penalty for worshipping something else was to be thrown into the lion’s den and they said, “Well, king live forever, looks like Daniel has been violating this edict. You have got to throw him in the lion’s den.”

Well, the king didn’t want to do this because he really liked Daniel. He thought this was a miserable way to proceed, and he didn’t want to do it, but then they said to him, “O king live forever, and remember a law of the Medes and Persians cannot be abrogated, even by the king himself.” So once it’s put in place, not even the king himself can change it or abrogate it or go against it.

That is sort of the suggestion that you get here from Bultmann. Bultmann thinks, “Maybe God created the world and set it up in a certain way, but once he did that, not even he can interfere in it”—he uses that word interference—“not even he can do anything in it. He just has to keep hands off.” It is like the law of the Medes and the Persians.

Another theologian who agrees is John Macquarrie, who says,

The way of understanding miracle (and that would be one kind of special divine action) that appeals to breaks in the natural order and to supernatural intervention belongs to the mythological outlook, and cannot commend itself in a post-mythological climate of thought. The traditional conception of miracle is irreconcilable with our modern understanding of both science and history. Science proceeds on the assumption that whatever events occur in the world, can be accounted for in terms of other events that also belong within the world, and if on some occasion, we are unable to give a complete account of some happening, the scientific conviction is that further research will bring to light further factors in the situation that will turn out to be just as imminent and this worldly as the factors already known.

Ok again, no room there for special action. And the third thinker here, Langdon Gilkey (still another theologian), says something similar, but I will pass. I will not read that one in the interest of saving a little bit of time, but these three theologians, plus many others want to assert that there is something wrong with the idea of God acting in the world, acting in the world in a way that goes beyond creation and sustaining, or creation and holding things in existence. So they think, “Ok, God created the world; God sustains it in existence”…that is ok with them, but anything beyond that, God performing any miracles, raising Jesus from the dead, or for that matter working in somebody’s heart and mind in a special way, that, they say, is a real problem. The question is, what is the problem?

Well, the next little bit here…according to the Christian and theistic idea, God is a person; he has knowledge, loves, and hates. He has aims and ends. He acts on the basis of his knowledge to achieve his ends. He is all-powerful, all-knowing, and wholly good. Thirdly (noted above by the Heidelberg catechism), God has created the world. Fourth is God conserves and sustains and maintains in being this world he created, but fifth, at least sometimes, God acts in a way going beyond creation and conservation in miracles, but also in his providential guiding of history, his working in the hearts of people, his internal instigation of the Holy Spirit, and so on, and it is with that fifth category that these people have a problem. It is God’s special action in the world—action beyond conservation and creation—and miracles would be an example.

So we might think of these theologians as endorsing what we could call hands off theology. God has got to keep his hands off. God could create the world. God conserves the world, sustains it in being, but he can’t do anything else—that is as far as he could go. It is hands off theology, and Bultmann, even in this context, even talks about interfering. I mean if God did something in the world that would be interfering, which, when you think about it, is a sort of strange thing to say—I mean if God created the world, he is the omnipotent, omniscient, holy, good creator of the world—when you accuse someone of interfering, you are saying they are doing something they should not be doing, right?

So Bultmann thinks if God did something in the world that would be interfering, and he should be ashamed of himself. Ok, now why is this a problem? Their suggestion is that somehow it is contrary to science. It is contrary to science the suggestion that God acts specially in the world. I didn’t read that bit, but Gilkey says, "The causal nexus in space and time which the enlightenment science and philosophy introduced into the western mind is also assumed by modern theologians and scholars. Since they participate in the modern world of science, both intellectually and existentially, they can scarcely do anything else.”

From a presentation sponsored by Biola University’s Center for Christian Thought, and delivered February 12, 2012 at EV Free Church, Fullerton, CA. Used by permission.

Darwin’s finches are some of the most visible and recognizable symbols of evolution in the world today. Biology textbooks feature them prominently, and the National Academy of Sciences has enshrined them in the entrance of their headquarters in Washington, DC. Surely the finches that Darwin collected on the Galápagos islands were a central feature of his evolutionary theory, right?

Lobby of The National Academies Building. Courtesy of CPNAS. Photo by Robert Lautman

Actually, the Galápagos finches are never even mentioned in Darwin’s famous work On the Origin of Species. Nor do they appear in Darwin’s famous notebooks on “Transmutation of Species”, in which he formulated the idea of evolution by natural selection.¹ Even Darwin’s private diary of his voyage on the HMS Beagle only mentions the Galápagos finches briefly in passing.²

It was only in 1845, in the second edition of The Voyage of the Beagle, that Darwin included a tantalizing sentence about the Galápagos finches:

Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.³

However insightful this statement may have been, Darwin never published anything else about the Galápagos finches for the rest of his life. Nor did he publically present these birds as direct evidence for this theory of evolution.⁴

If these finches were so important to Darwin’s evolutionary theory, why did he remain silent about them? One of his comments in The Voyage of the Beagle provides us with a clue:

Unfortunately most of the specimens of the finch tribe were mingled together; but I have strong reasons to suspect that some of the species of the subgroup Geospiza are confined to separate islands.⁵

When Darwin was exploring the Galápagos himself in 1835, he had not formulated his theory of evolution yet, and thus he did know what data would be necessary to make definitive conclusions about finch evolution. In particular, he did not keep careful track of which of his specimens came from which islands. Moreover, as was customary among naturalists at that time, Darwin only collected a small number specimens—he brought home only 31 finches and 64 total birds from the Galápagos.⁶

Though Darwin sensed that these birds were truly special, he lacked sufficient evidence to reach any specific conclusions about their evolutionary origins. It would be up to the rest of the scientific community to carry out the necessary empirical research. Subsequent expeditions in 1868, 1891, 1897, and 1905 brought back thousands of Galápagos finch specimens, but instead of unlocking the mysteries of evolutionary theory, the Galápagos finches became a great enigma.⁷

A century after Darwin's voyage, scientists still struggled to explain the staggering variety of finches on this tiny, remote archipelago. By the mid-1930’s, British Museum ornithologist Percy Lowe argued that the finches presented a "biological problem of first class importance", and he told the British Association for the Advancement of Science that the finches displayed a "bewildering diversity, intergradation, and distribution".⁸ Who would be up to the challenge of making sense of such tremendous biological complexity? It was David Lack.

David Lack

Ornithologist David Lack

David Lack had an exceptionally keen eye for bird-watching, and he possessed a passion to match it. By age 15, he had already observed 100 distinct species of birds, and before entering college, authored his first scientific paper. At Cambridge University in the early 1930’s, Lack was disappointed to find that his zoology professors taught “nothing about evolution, ecology, behavior or genetics, and of course nothing about birds.”⁹ In fact, at that time, there were only two professional ornithologists in all of Britain!

Thus David Lack took it upon himself to create his own learning opportunities. As an undergraduate, he became the president of the Cambridge Ornithological Club, traveled to Greenland for a bird-watching expedition, and cultivated a relationship with the prominent biologist Julian Huxley (grandson of Thomas Henry Huxley). Huxley was an inspiring mentor and encouraged Lack to expand his research further by studying tropical birds.¹⁰ Following this advice, Lack embarked on a research trip to Tanzania in the summer of 1934, but his greatest adventure was yet to come.

In 1937, Lack became fascinated by the scientific mysteries surrounding the Galápagos finches. But in order to study their behavior, Lack would need to travel to remote islands halfway around the world. How could he possibly get there? Once again, Julian Huxley was tremendously supportive and raised funds from two prominent scientific societies to pay for his expedition. After a long delay, David Lack and five companions finally set off on their journey.

Instead of residing in comfortable quarters aboard a royal naval ship, Lack’s group subsisted on a shoestring budget, traveled on commercial steamers, and stayed with local settlers. Their experience was definitely not a romantic tale of imperial expedition:

The Galápagos are interesting, but scarcely a residential paradise. The biological peculiarities are offset by an enervating climate, monotonous scenery, dense thorn scrub, cactus spines, loose sharp lava, food deficiencies, water shortage, black rats, fleas, jiggers, ants, mosquitoes, scorpions, Ecuadorian Indians of doubtful honesty, and dejected, disillusioned European settlers.¹¹

Whereas Charles Darwin spent only nineteen days on the shores of the Galápagos, Lack and his crew conducted more than five months of meticulous and exhausting study in the harsh climate. At that time, even the finches themselves provided little solace. Lack wrote,

Darwin’s finches are dull to look at, not only in their orderly ranks in museum trays, but also when they hop about the ground or perch in the trees of the Galápagos, making dull unmusical noises. Only the variety of their beaks and the number of their species excite attention.¹²

Large Cactus Finch on Española Island in the Galápagos Islands

The repetitive tedium requisite for important scientific discoveries is rarely discussed in public, and even today many bright-eyed science students become disillusioned by the painstaking work demanded by their Ph.D. programs. But one of the things that distinguishes great scientists is their unwavering commitment and tenacity in completing major projects. David Lack's efforts were not in vain:

"Despite his personal discomforts (or perhaps because of them), Lack did see something on the Galápagos that no one had ever seen before—natural selection at work among its finches through interspecies competition." ¹³

When the birds’ breeding season ended in 1939, Lack was ready to return to his home in England. But the captive finches that he had brought with him fared so badly on the voyage home that he detoured to San Francisco and put them in the care of the California Academy of Sciences. Turning this mishap into an opportunity, Lack stayed there for five additional months to study the Academy’s enormous collection of Galápagos finch specimens.¹⁴

To complete his systematic research, Lack then travelled across the United States to study the Galápagos finch collection housed at the American Museum in New York.¹⁵ Altogether, Lack examined more than 8000 specimens and specifically measured the length, width, and depth of all their beaks.¹⁶

Lack’s final obstacle was in getting his research published. Though he completed his academic manuscript “The Galápagos Finches—A Study in Variation” in 1940, paper shortages during World War II delayed its publication by the California Academy of Sciences until 1945. Were he only interested in making an original contribution to science, Lack could have stopped here and congratulated himself on a job well-done. However, his motivation sprung from a deeper source:

David Lack's drawing of 14 species of Galápagos finches, p. 19 of Darwin’s Finches

"I did not watch birds primarily for scientific reasons but for sheer enjoyment, and from the age of 15 onward returned day after day in a glow of excitement after seeing a new bird or a new habit." ¹⁷

Lack’s joyful fascination with the Galápagos finches inspired him to continue developing his conclusions long after returning from his expedition. While waiting for his academic paper to be published, he began writing a book that would enable students and the general public to share his excitement about these remarkable birds and the evolutionary processes that shaped them.

First published in 1947, Lack’s book became tremendously influential. Before this time, biology textbooks had never even mentioned the Galápagos finches. But after David Lack’s study, the finches became a primary example of evolution by natural selection, specifically adaptive radiation. Not only did textbooks fully rely on Lack’s findings, they also followed his lead in calling them “Darwin’s finches”, the title of Lack’s famous book.¹⁸

Iconic Finches

What was it about these birds that made them such a prominent symbol of evolution? As Darwin himself pointed out, the numerous Galápagos finch populations each have distinctive beaks, and he speculated that they could have evolved from an ancestral species that came to the islands. But a complete picture of finch evolution would have to wait another hundred years, when David Lack arrived.

During his five months on the Galápagos, including both the rainy and dry seasons, Lack observed that these beak differences enable the finches to subsist on different kinds of food:

The beak differences between most of the genera and subgenera of Darwin's finches are clearly correlated with differences in feeding methods. This is well borne out by the heavy, finch-like beak of the seed-eating Geospiza, the long beak of the flower-probing Cactornis, the somewhat parrot-like beak of the leaf, bud, and fruit-eating Platyspiza, the woodpecker-like beak of the woodboring Catcospiza, and the warbler-like beaks of the insect-eating certhidea and Pinaroloxias.¹⁹

Lack's image of beak adaptations from Darwin’s Finches

Specializing in such different sources of food enables these finches to live in close proximity without directly competing with each other or driving populations to extinction. The fact that so many of these closely related finches are able to co-exist is a remarkable fact in itself. As Lack himself put it, “It is not only the origin, but also the persistence, of new species which require explanation.”²⁰

But it is also fascinating to consider how these birds got to be so different in the first place. How did a finch come to have a beak like a “parrot”, “woodpecker”, or “warbler”? The answer lies in the distinct characteristics of the Galápagos. Because the islands are so remote, no actual parrots, woodpeckers, or warblers ever settled on it. In the absence of these species, the Galápagos finches were able to adopt feeding habits and forms that they would never have taken on a large continent full of other birds competing for food. The isolation of these islands offered just the right conditions for us to see living examples of adaptive radiation.²¹

Conclusion

Considering the immense popularity of the Galápagos finches, it is quite surprising to learn that Charles Darwin himself had so little to say about them. In fact, it was actually David Lack, one century later, who conducted the critical research that immortalized the finches in biology textbooks and popular lore. By naming his landmark book Darwin’s Finches,²² Lack paid homage to the man whose voyage on the HMS Beagle helped transform the study of natural history. But at the same time, Lack also obscured the fact that evolutionary biology is an enterprise conducted by a large community of brilliant scholars, not just the product of one man’s efforts.

This tendency to immortalize “great men of science” has also led many people to refer to modern evolutionary theory as Darwinism, despite the fact that it has substantially changed and developed over the past 150 years. It is important to give credit where credit is due, and if that’s the case, we should seriously reconsider how we refer to the Galapagos finches. Evolutionary biologist Dolph Schluter, who studied the finches several decades after David Lack, had this to say:

I find Lack's intuition really stunning given how little information he had. He's my hero actually… They should be called Lack's finches.²³

In the second part of this series, we’ll explore the fact that David Lack, in addition to being a world-renowned evolutionary biologist, was also a devout Christian. His study of evolutionary theory did not cause him to lose his faith; in fact, he actually converted to Christianity after completing his Galápagos finch research.

For Discussion

Further Reading

• Grant, Peter R.; Grant, B. Rosemary. How and Why Species Multiply: The Radiation of Darwin's Finches, Princeton University Press, 2008.
• Sulloway, Frank J. (Spring 1982), "Darwin and His Finches: The Evolution of a Legend" (PDF), Journal of the History of Biology 15 (1): 1–53.
• Weiner, Jonathon. The Beak of the Finch: A Story of Evolution in Our Time. Vintage Books, 1995.

Notes

1. Sulloway, F. (1983). "Darwin and his finches: The evolution of a legend." Journal of the history of biology 15(1): 32. Darwin’s notebooks on transmutation mentioned Galapagos tortoises and mockingbirds, not finches.
2. Lack, David. Darwin’s Finches. Cambridge University Press, 1947: 9. Confirmed by Sulloway (1983), p5.
3. Darwin, Charles. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world. London: John Murray. 2d ed. 1845: 379-80. This edition of the book also contained the drawings of four different finches that have become enshrined in biology textbooks and on the walls of the National Academy of Sciences in Washington, DC.
4. Sulloway, p35. Sulloway points out that the first published evolutionary account of the Galapagos finches was not until 1876, by Osbert Salvin: "On the Avifauna of the Galapagos Archipelago." Trans. Zool. Soc. London, 9:447-51.
5. Darwin (1845), p395.
6. Sulloway, p40.
7. Sulloway, p40.
8. Larson, E. J. Evolution's Workshop: God and Science on the Galapagos Islands. New York, Basic Books, 2001: 166-67.
9. Lack, David. (1973) “My life as an amateur ornithologist.” Ibis: 424.
10. Lack (1973), 425-27.
11. Lack (1947), p1.
12. Lack (1947), p11.
13. Larson, 167-68.
14. The California Academy of Sciences sponsored an expedition to the Galapagos in 1905-06 and collected nearly 9000 Galapagos finch specimens (Sulloway, p40).
15. In New York, Lack roomed with the curator of the finch collection—German émigré zoologist Ernst Mayr. By developing this relationship, Lack had close ties with two of the biggest figures in the neo-Darwinian synthesis, Julian Huxley and Ernst Mayr (Larson, 168).
16. Larson, p168.
17. Lack (1973), p424.
18. Larson, p198.
19. Lack (1947), p60.
20. Lack (1947), p158.
21. See Lack’s concluding chapter on “Adaptive Radiation”, pp146-159 of Darwin’s Finches (1947).
22. British ornithologist Percy Lowe originally proposed the name “Darwin’s finches” in 1935, but the name did not catch on until Lack used it in his book. See P.R. Lowe, (1936) "The Finches of the Galapagos in Relation to Darwin's Conception of Species." Ibis, 13th ser., 6:310-321. (Cited in Larson, p287)
23. Schluter, in an interview with Edward Larson, 16 March 2000.

Eugene Dubois

13 years before, in 1877, Dubois had arrived in Amsterdam to study medicine, but always harboring a desire to study the ancestry of modern humans. So, after four years at the University there, he accepted an invitation to go to the University of Utrecht to study comparative anatomy and devote himself to the latest thinking about the origins of the human species. It was during his time at Utrecht (from 1881 to 1887) that Dubois became enamored of Haeckel’s views on human origins, which differed from those of Darwin. While Darwin argued that humans had evolved in Africa, the region in which our closest living relatives—the chimpanzees and gorillas—still live, Haeckel believed that the origins of humanity lay in East Asia. This was so, he believed, because of his own observations of gibbons that walk bipedally when on the ground.

Haeckel also believed that there had once been a large landmass called Lemuria between the continents of Africa and Asia. In his view, Lemuria had since become submerged, leaving the modern islands of Madagascar and the East Indies as its only remains. The idea of submerged continents was not unusual for the late 19th-century, as people struggled to understand the character of biological diversity present in the world and why there were such striking similarities between animals that were geographically dispersed. The geographical distribution of marsupial fossils in South America and Australia is an example of this sort of problem, and one that was not solved until the second half of the 20th century when continental drift reconstructions suggested that ancient marsupials had used Antarctica as a conduit between the other two continents. Not only did such theories make sense of modern distributions, they were confirmed with later discoveries of marsupial fossils in Antarctica.

In any case, in 1888 Dubois joined the army and set out for the Dutch East Indies to pursue his ideas. For the next two years, he would comb Sumatra attempting to locate the hominin remains that Haeckel promised would be there. In hindsight, what Dubois was attempting was something that had never been done before: discovery of hominin material through the tools of archaeological excavation. Up to this point, all of the human fossils had been found on the surface, eroding out of the side of a bank, or as a result of farming. It had not occurred to anyone to go looking for human ancestors.

Now, with his supply of prison workers dwindling due to desertion and fever, he had almost run out of options and was on the verge of failure. Using almost all of his remaining resources, he decided to abandon his excavations on Sumatra and turn to the nearby island of Java. Emboldened by the fact that early modern human fossils had been discovered there (at Wadjak), he arrived and settled in at Trinil, on the banks of the Solo River, in 1890.

Figure 1: Dubois' Pithecanthropus erectus

The very next year, Dubois’ long-standing efforts were finally rewarded, first with the discovery of a skullcap (calvaria) of a hominin cranium, and then with an intact femur (Figure 1). Judging by what he knew of cranial anatomy, Dubois estimated that the skull would have been approximately 900 cubic centimeters (cc) in volume, placing it below even the lowest threshold of modern humans. Further, he noticed that it was not like modern humans in shape, being too long and low. He concluded that it showed “evidence of a form intermediate between man and the anthropoid apes” (Dubois, 1896). Dubois envisioned a sequence of forms in which the gibbon gave rise to a form of chimpanzee called Anthropopithecus sivalensis, which then gave rise to the form represented by the Trinil remains, after which Homo sapiens arose (Turner, 1895).

Dubois spent the next twenty years on the road with his find, trying to drum up support for its place in human prehistory. As with Raymond Dart’s discovery of the first australopithecine thirty-three years later, Dubois did not receive a warm reception. Most critics simply said that he had gotten it wrong and that the femur did not belong to the same individual as the obviously-primitive skull cap. Some of the criticism Dubois suffered could have been mitigated had he been more open to sharing the Trinil materials; but, instead, he allowed very little access to the bones, so that very few people knew exactly what they looked like. Adding to Dubois’s credibility problems was the 1911 “discovery” of Piltdown. This intentional hoax turned the paleoanthropology world on its head for forty years, sending researchers down innumerable rabbit holes. As I noted in a previous post, the Piltdown remains made all of the other hominin finds appear too “ape-like” to be on the road to humanity and informed many opinions about finds such as those from Trinil.

On the other hand, some critics of Dubois’ new hominin claim were vicious, and questioned both his academic abilities and his judgment (Shipman & Storm, 2002)—in addition to the interpretation of the find itself. It was in reference to Dubois’ work that the term “Missing Link” was first used with reference to a particular human fossil, originating with Charles Lyell (1863) and describing palaeontological gaps. And ironically, it was in one of the most stinging criticisms of Dubois’ work that the name that would eventually stick was first used: “Homo erectus.” Eventually, many other finds in the same general area and across Southeast Asia demonstrated that what Dubois had found was a real, previously-unknown hominin form, and the first to colonize the Asian continent and the islands leading off towards Oceania.

Homo erectus across South East Asia:

Figure 2: Sangiran 17

Sangiran

The earliest point at which Homo erectus appears to have begun to colonize the greater East Asian region is around 1.8 million years ago, represented first by the partial child’s skull found at the site of Modjokerto, and then, at around 1.66 million years ago, at the site of Sangiran, in Trinil, where Dubois had made his landmark discovery. This site was rich, yielding the remains of many crania, perhaps best represented by Sangiran 17 (Figure 2), an almost complete skull.

The material from the Sangiran site is very diverse morphologically, with some crania having capacities of as little as 700 to 800 cc, and other, larger heads with volumes in the range of 1000 cc. As with the late Homo ergaster finds from Africa, the remains from Sangiran yielded crania that were still widest at their bases, possessing large brow ridges. Some have thick cranial bones and are very robust (Sangiran 4), while others are very gracile (Sangiran 31). What this variation means is not clear, but most workers believe it represents a very diverse diachronic population (that is, one group living and moving around over a long period) rather than separate species inhabiting the area. The Sangiran site yielded fossil material in an almost continuous succession from approximately 1.66 million years ago to less than 800,000 years ago.

Because the area of the excavations—the Sangiran Dome—is a volcanic deposit, the layers have been securely dated by the ⁴⁰Ar/³⁹Ar method, although questions remain about the historical sequence and distribution of other animals that lived there through the ages (its faunal succession). The problem is that many of the fossils were not found in context, and relating them directly to the stratigraphy is tenuous. Despite this, most workers are comfortable with the earliest hominins in the region being at least 1.5 million years old.

One of the things hampering workers in this region is the comparative paucity of recovered stone tools. Those that have been found suggest a technological stage similar to the late Oldowan design, equivalent to that being created by the Homo ergaster populations inhabiting the area of Dmanisi and East Africa. Unfortunately, none of the tools have been associated with the hominins directly so it is not exactly clear who made them.

Figure 3: Sambungmacan 3

Sambungmacan

Another major find from the area where Dubois brought Homo erectus to light is the cranium from the site of Sambungmachan. This skull was reportedly found in 1977 but was then illegally sold to the antiquities market, where is spent considerable time in different collections before being “rediscovered” in 1998—in a New York nature curio shop called Maxilla and Mandible, Inc. (Delson et al., 2001). This was an almost-complete calvaria (Figure 3), with only part of the base missing. It is equivalent in size to the fossils from Sangiran, with a cranial capacity of around 1000 cc. It has a large brow ridge extending all of the way across the top of the eyes, a long, low cranium with a sloping forehead and a maximum width near the cranial base—all features that are also characteristic of the late African H. ergaster and Sangiran crania. Although we will never know exactly how old this cranium is, its morphology is consistent with that of the material from Sangiran.

Figure 4: Ngandong 6

Ngandong

Later in time, but also located on the Solo River, is the site of Ngandong, excavated by Oppenoorth in the early 1930s. At this site, fourteen calvaria have been discovered, all of which show advanced Homo erectus characteristics: long and low in shape, with thick-bones and a distinctive brow-ridge. (Figure 4). As with the other Indonesian finds, dating the Ngandong material has been problematic. The deposits at the site were originally thought to be around 100,000 years old, but this interpretation was turned on its head in 1996, when Swisher and colleagues claimed that the deposits were no older than between 27,000 and 53,000 years old (Swisher et al., 1996). These age estimations were made on the associated fauna, however, and as Rainer Grün and the late Alan Thorne pointed out, the faunal material does not match the skulls either in color or in texture and is likely not from the same time. Recently, Swisher and colleagues revisited the dating of the site and derived internally-consistent dates of at least 143,000 years before the present (Indriati et al., 2011). As with the Trinil remains, however, there are no associated stone tools.

Homo erectus in China

The Chinese Homo erectus material is very widely scattered and working in the region has presented many difficulties for researchers in terms of transport, language barriers and funding. Consequently, we know less about this region and its previous inhabitants than we do about most other areas of the Old World. Although there are between ten and fifteen sites that have yielded Homo erectus material, I will only touch on the most important ones.

Lantian:

Figure 5: Lantian

In the early 1960s, a cranium and mandible were found in the cave of Lantian, Shaanxi province, whose characteristics matched other remains from China designated as Homo erectus. Paleomagnetic dating has yielded a date no earlier than 1.15 million years ago for the skull, with the consensus being that it is around 800,000 years old. A date of approximately 650,000 years before the present was derived for the mandible. The cranium is heavily encrusted and suffered from postmortem deformation (Figure 5). When reconstituted, it was found to have a capacity of around 780 cc (low for Homo erectus) and the bones on the sides of the head are the thickest yet recorded. At this site some flake tools, mammal remains, and an ash deposit were all recovered, suggesting hunting and control of fire.

Figure 5: Hexian

Hexian

Another almost-complete calvaria was found at Longtandong cave in the province of Hé Xiàn, dated to between 400,000 and 500,000 years ago. This find exemplifies typical Homo erectus in many ways in that it is long and low, with heavy muscle markings toward the base and the rear of the skull (Figure 6). The cranial capacity is around 1000 cc, a third-again greater than that of the Lantian calvaria. Its cranial shape is very similar to those found in Southeast Asia, suggesting that it straddles the Southeast Asian and Chinese boundary.

While both Lantian and Hexian were significant finds, another site in China boasted the single largest collection of Homo erectus fossils ever found at one site, as well as presenting one of the greatest mysteries in paleoanthropology. Tomorrow, in the conclusion of our look at Homo erectus in Asia, we’ll peer into the Zhoukoudian caves and consider how this species fits into the lineage of man.

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.

(Written by the BioLogos editorial team)

In a recent lecture in Washington, D.C., Intelligent Design advocate Stephen Meyer noted that scientists and theologians are generally uncomfortable with the idea of "supernatural intervention" in natural processes such as evolution. He then posed the question, “What's so bad about supernatural intervention?” Meyer’s comment touches on a point of particular tension among Christians engaged in understanding how our science and our theology interact: the nature of divine action.

Much of the confusion in this area, however, stems from the inexact meaning of intervention, which—like evolution or Darwinism—implies different things to different people. All Christians affirm that God works powerfully in the world, doing extraordinary acts of creation and salvation. In common conversation, then, intervention tends to mean simply “acts that are recognizably or obviously God’s,” whether as dramatic as the parting of the Red Sea or as subtle as an individual believer hearing a clear call to repentance or to mission from the Lord. Even in this most casual sense, intervention tends to mean special occasions of God’s providential care, rather than his ordinary sustaining work.

But to Christian scientists and philosophers trying to understand God’s action in creation—especially how he might go about his sustaining role—intervention has another connotation: namely, that recognizing something as “divine action” requires it to be in violation of the natural laws which God himself established. Put another way, many Christian thinkers associate the word intervention with the idea that to act in the world God “must” act from outside the world. That view is a central tenet of deism, not Christianity. One response to Meyer’s comment, then, is to ask whether intervention is the only (or even a helpful) way of thinking about God’s work in biological creation. Is there another way of talking about “divine action” that does not restrict God's work to only extraordinary events? Can we conceive of divine action in a way God is never absent, distant, or in any way removed from the creation he sustains at every moment?

Finding such an alternative vocabulary to talk about the different ways God acts in his creation is the purpose of this short series introducing the work of theologian and physicist Robert John Russell. Russell’s book Cosmology: From Alpha to Omega explores the history of Christian thinking about divine action and proposes one model for how we might understand it in light of Scripture, the traditions of the church, and contemporary scientific explorations of the material world.

To be clear, Russell argues that God does unmistakably act in the world. He singles out the bodily resurrection of Jesus not only as a prime example, but as a truly unique event distinct even from Christ’s other miraculous acts during his ministry on earth. That is, the resurrection was an in-breaking of God’s new reality into the present one, something “beyond miraculous.” This series, though, offers his perspective on the more basic issue of how God might be at work in what we have called the “ordinary processes” of his world.

We begin our three-part series below with Professor Russell’s description of how views of divine action have changed throughout history (excerpted from Chapter 4 of Cosmology: From Alpha to Omega).

Historical background to the problem of divine action

The notion of God’s acting in the world is central to the biblical witness. From the call of Abraham and the Exodus from Egypt to the birth, ministry, death and raising of Jesus and the founding of the church at Pentecost, God is represented as making new things happen. Through these “mighty acts,” God creates and saves. Rather than seeing divine acts as occasional events in what are otherwise entirely natural and historical processes, both the Hebrews and the early Christians conceived of God as the creator of the world and of divine action as the continuing basis of all that happens in nature and in history.

The view that God works in and through all the processes of the world continued throughout Patristic and Medieval times. For example, God was understood as the first or primary cause of all events—where all natural causes are instrumental or secondary causes through which God works. The conviction that God acts universally in all events, and that we act together with God in specific events, was maintained by the Reformers and the ensuing Protestant orthodoxy. John Calvin (1509-1564) argued that God is in absolute control over the world and at the same time maintained that people are responsible for evil deeds. Questions about human freedom and the reality of evil were seen more as problems requiring serious theological attention than as reasons for abandoning belief in God’s universal agency.

Moreover, faith in God the creator was articulated through two distinct but interwoven doctrines: creation and providence. The doctrine of creation asserts that the ultimate source and absolute ground of the universe is God. Without God, the universe would not exist, nor would it exist as “universe.” Creation theology, in turn, has often included three related but distinct claims: 1) the universe had a beginning; 2) the universe depends absolutely and at every moment on God for its sheer existence; and 3) the universe is the locus of God’s continuing activity as Creator. The first two have traditionally been grouped in terms of creatio ex nihilo(creation from nothing), and the third in terms of creatio continua (continuing creation).

The doctrine of providence presupposes a doctrine of creation, but adds significantly to it. While creation stresses that God is the cause of all existence, providence stresses that God is the cause of the meaning and purpose of all that is. God not only creates but guides and directs the universe towards the fulfilling of God’s purposes. These purposes are mostly hidden to us, though they may be partially seen after the fact in the course of natural and historical events. The way God achieves them is hidden, too. Only in the eschatological future will God’s action throughout the history of the universe be fully revealed and our faith in it confirmed. General providence refers to God’s universal action in guiding all events; special providence refers to God’s particular acts in specific moments, whether found in personal life or in history.

Divine intervention arises in the Enlightenment

The rise of modern science in the seventeenth century and Enlightenment philosophy in the eighteenth, however, led many to reject the traditional views of divine action. Although Isaac Newton (1643-1727) argued for the essential role of God in relation to the metaphysical underpinnings of his mechanical system, and in this way defended the sovereignty of God in relation to nature, Newtonian mechanics depicted a causally closed universe with little, if any, room for God’s special action in specific events—and then only by intervention: that is, by acting as from outside that closed system. A century later, Pierre Simon Laplace (1749-1827, pictured left) combined the determinism of Newton’s equations with epistemological reductionism (the properties and behavior of the whole are reducible to those of the parts) and metaphysical reductionism (the whole is simply composed of its parts), to portray all of nature as a causally closed, impersonal mechanism. This in turn led to the concept of interventionism: if God were really to act in specific events in nature, God would apparently have to break the remorseless lock-step of natural cause and effect by intervening in the sequence and violating the laws of nature in the process.

The eighteenth century also saw the rise and fall of deism, in which the scope of divine agency was limited to an initial act of creation. According to deism, the universe was like a clock which, once built and set in place, proceeded to run on its own. David Hume (1711-1776) challenged the deistic (and theistic) arguments for God as first cause and as designer. In response, Immanuel Kant (1724-1804, pictured right) constructed a new metaphysical system which emphasized the mind’s role in organizing sense-data through universal categories of intuition and forms of sensibility. According to Kant, the sphere of religion lies not in our knowing (the activity of pure reason) but in our sense of moral obligation (the activity of practical reason). It is our ethical system, not our knowledge of nature, that requires us to postulate God, freedom and the immortality of the soul. The consequence of Kant’s thought for the West was the philosophical separation of the domains of science and religion into “two worlds”—a move which was to have an immeasurable effect on Christian theology up to the present.

Theology splits into conservative and liberal interpretations of divine action

As a consequence of the philosophical division of science and religion, theology in the nineteenth century was faced with a fundamental challenge not only to its contents and structure, but even to its method. The variety of responses to this challenge tend to fall into two groups: “liberals” largely accepted and worked within the terms of the discussion that modernity dictated while “conservatives” upheld traditional formulations and tended to reject “modernity.” The earliest and most influential figure among liberals was Friedrich Schleiermacher (1768-1834), who responded to Kant by locating religion as neither a knowing nor a doing. Instead religion is grounded in personal piety—the feeling of absolute dependence.

Schleiermacher held that theological assertions emerge from the immediacy of the religious self-consciousness. He understood God’s relation to the world in terms of “universal divine immanence” [the idea that God is present to the entire cosmos at all times], and he blurred the distinction between creation and providence by collapsing the later into the former. In a famous move he defined miracle as “. . . simply the religious name for event. Every event, even the most natural and usual, becomes a miracle, as soon as the religious view of it can be the dominant.” Schleiermacher’s arguments became characteristic of liberal Protestant theology throughout the nineteenth century and continued into much of twentieth century theological work.

The second half of the nineteenth century saw the rise of Darwinian evolution, which combined random variation and natural selection to explain biological complexity. To some in the nineteenth and twentieth centuries, the fundamental role of chance in nature seemed to undercut any notion of divine action in the world; to others, such as the Anglo-Catholic liberal movement in Britain and America, Darwinian evolution could be accommodated and even integrated into theology without interventionism, since God works immanently in and through the very processes of nature. In contrast, religious conservatives tended either to reject evolution as a whole or give it a limited acceptance with the proviso that the objective acts of special providence constitute divine interventions in nature.

The rise of neo-orthodoxy in the twentieth century

Protestant theology in the first half of the twentieth century was largely shaped by Karl Barth. In his rejection of nineteenth-century liberal theology, Barth returned theology to its biblical roots and focused it on the God who is “wholly other.” Recognizing that a religion founded exclusively on subjective experience is vulnerable to the critiques of Feuerbach and Freud, Barth and his followers held fast to the objective action of God in creating and redeeming the world. “The Gospel is . . . not an event, nor an experience, nor an emotion—however delicate! ... It is a communication which presumes faith in the living God, and which creates that which it presumes.” The ‘God who acts’ became a hallmark of the ensuing “biblical theology” movement which arose in the 1940s and 1950s. To many this movement seemed to offer a tertium quid between liberal and conservative theologies.

But do Barthian neo-orthodoxy and the biblical theology movement actually produce a credible account of divine action? On the one hand neo-orthodoxy attempts to distance itself from liberal theology by retaining biblical language about God acting through wondrous events and by viewing revelation as including an objective act. Yet on the other hand, it, like liberalism, accepts the modern premise that nature is a closed causal system, as depicted by classical physics. The result is that neo-orthodoxy seems to assert a contradiction: God does act objectively in nature (as conservatives believe) and God does so without intervening, violating, suspending or obstructing the ordinary processes of nature understood as a closed causal system (as liberals believe).

A third way between liberal and conservative theologies

Any purported “third option” will require an intelligible concept of objectively special providence which does not entail divine intervention. Such a concept could serve as a genuine tertium quid to conservative and liberal notions of special providence, combining strengths borrowed from each. Specifically, we will seek to speak about special divine acts in which God acts objectively in an unusual and particularly meaningful way in, with, and through events which serve to mediate God’s action. We will seek to do so without entertaining—in fact by refusing—the additional claim that God must intervene in, or at least suspend, the laws of nature. Those laws are themselves the result of and description of God’s continuous creation, after all. I call this type of divine action Non-Interventionist Objective Divine Action (NIODA).

In part 2 of this series, Tom Burnett will explore in more depth what Russell takes to be wrong with the Enlightenment concept of “supernatural intervention.” Part 3 will explain and clarify Russell’s theory of NIODA.

From Chapter 4, “Does ‘The God Who Acts’ Really Act? New Approaches to Divine Action In Light Of Contemporary Science,” in Cosmology: From Alpha to Omega by Robert John Russell, copyright © 2008 Fortress Press. Reproduced by permission of Augsburg Fortress Publishers. All rights reserved. No further reproduction allowed without the written permission of the publisher.

This ongoing series grew out of a conversation that Kenneth Keathley, the Senior Vice President for Academic Administration at Southeastern Baptist Theological Seminary and I had last year. We agreed that he would solicit a set of essays from scholars at Southern Baptist Seminaries who would specifically identify their concerns about what they perceive to be the BioLogos view of creation. In response to this request, Dr. William Dembski of Southwestern Baptist Seminary submitted the essay “Is Darwinism Theologically Neutral?” Although I do not consider my view Darwinian, I am sure that my view and that of others associated with BioLogos is perceived that way by some, so this gives me an opportunity not only to respond to his analysis, but to clarify my position on creation and how I think it is distinct from what Dembski calls “Darwinism."

God’s Activity in Creation

I will begin by summarizing my view of the nature of God’s activity in creation. I think that God created all living organisms, including humans, through the evolutionary process. Acceptance of creation through evolution does not mean that I reject the notion of a miracle-working God. On the contrary, I believe in the miracles of Scripture, and I believe that we’ve experienced God’s supernatural activity in our own lives. I stand in awe of a personal God whose activity is not constrained by natural laws, but also includes supernatural acts.

But what are the natural laws? Are not the the laws of nature simply a description of God’s ongoing and non-ceasing activity in the universe? The Law of Gravity, for example, is not something that God set up in the beginning, thereafter recusing himself from further involvement and exiting from the scene. Instead, the Law of Gravity works as it does because of the ongoing activity of God’s Spirit in the universe. So consistent is that activity that it can be described mathematically through scientific analysis. If God ceased to be active, however, then not only would the matter of this universe no longer function in a way which enables a mathematical description of gravity, matter itself would cease to exist. Paul, referring to Christ, writes “All things are created by him and through him.” Continuing, he goes on to state that “He himself is before all things and in him all things hold together” (Colossians 1:17). So he created in the beginning and, indeed, “…without him not one thing came into being.” (John 1:3) But it doesn’t end there: his ongoing activity is necessary for the universe to function. As the writer to the Hebrews declares “He sustains all things by his powerful word.” (Hebrews 1:4) The laws of nature, then, are simply a description of the ongoing activity of God which—because it is so consistent, dependable, and pervasive—points to the trustworthiness of God. Put another way, the activity of God is not restricted to that which we call the supernatural; it is all God’s activity. It is just that some aspects of God’s activity are so consistently repeatable that we can develop laws which describe the regularity of the divine activity which “holds” and “sustains” the universe. This latter type of activity is no less magnificent just because God does it continuously. Indeed, the Psalmist marveled at God’s natural activity and worshipfully reflected upon it.

On the other hand, the God we know through Scripture and personal experience also works in ways that are not mathematically predictable. We call this aspect of God’s action supernatural, and we seem to think of this facet of God’s work—this law-defying activity—as being more God-like. Indeed calling it super-natural suggests we think of it as God’s “turbo-charged” activity. But are not miracles simply a reflection of God choosing to work in a unique, non-customary manner to accomplish God’s purposes in God’s time? (See here for more detail.) When God works in this way, Scripture generally presents such activity in the context and purpose of God’s desire to enter into or renew a relationship with an individual or with a community of people. For example, God’s miraculous involvement in the lives of the elderly couple, Abraham and Sarah, led to the birth of their son, Isaac, and marks the beginning of God’s very special relationship with their descendents. God’s interaction with Moses through the burning bush initiated a new phase of God’s relationship with the Hebrew people as they moved out of slavery and back into the Promised Land. And of course, the supreme examples of miraculous activity are the incarnation, the empty tomb, and the resurrected Body. We worship a personal God whose desire for an ongoing loving relationship with humankind is first laid out in the early chapters of Genesis, but does not end there. In all divine activity—supernatural and natural—God is just being who God is: Creator, Sustainer, and loving Father. There are not two sets of activities, even though we label them “super” and “ordinary.” All are “super,” because all describe the activity of our supernatural God. Some are regular, predictable and ongoing, while other activities of God are not, for reasons often based in the fact that God is lovingly responsive and relational.

The Genesis narrative gives us no details about the mechanism by which God brought the universe and life into existence. God gave the charge: “Let there be lights in the dome of the sky..., “ “Let the waters bring forth…,” “Let the land bring forth…,” “Let the birds multiply…,” and, in response, we are told, it happened. Scripture does not explain how it happened, although as we read God’s other book—the book of nature—we see that God’s work extended over a long period of time. In these details, the Bible does not say whether the “bringing forth” was fulfilled through God’s natural activity (that which is regular, ongoing, and can be described by science) or God’s supernatural activity (that which is not regular and predictable). Given the many examples of supernatural activity in Scripture, we human beings tend to expect that for something as special as creation of stars or new species, supernatural activity would have been required. But we cannot derive this from the scriptural account and, therefore, it is wise not to second-guess how God might have worked based on the Scriptures.

Indeed, the distinction is softened by Scripture itself, which often speaks of God’s natural activity in ways that sound supernatural. For example, the Psalmist writes of God opening his hand to feed the living creatures (Psalm 104:28). We know how God does this and so did the Psalmist—he did it through natural means—but it was still God’s process and God’s provisions. Job speaks of thunder as being the voice of God (Job 40:9). We know God’s natural activity produces thunder and we can describe the laws that are responsible for it, but the fact that we know how it works certainly doesn’t negate the point being made in the book of Job. When the Psalmist describes the heavens as being the work of his fingers (Psalm 8:3), this does not negate astronomy’s description of the regular and ongoing processes that give rise to stars in God’s universe. Those processes are natural, but they are every bit as much God’s activity as if he were to take huge balls of matter and miraculously fashion sparkling stars with his hands.

Still, given that there is extensive supernatural activity exhibited in God’s interaction with Israel and in the life of Jesus, it is entirely possible that he did work supernaturally in fulfilling the creation command, as well. Even though the miracles described in the Bible primarily serve some theological or pastoral purpose that stems from God’s earnest desire to make his presence known and to deepen his relationship with humankind, we should reserve judgment about whether only God’s natural activity was responsible. It is not clear though, that supernatural activity would often be God’s chosen mode of action millions of years before humans had arrived. Thus, we should not assume with certainty that God would choose to use supernatural flurries of activity if his ongoing regular activity—that described through natural laws—would accomplish the same end, albeit over a longer period of time. For all we know, God may prefer slowness, even though we seem to be inclined to think that faster is better. After all, in the history of Israel and the church, God gave no new prophecy for 400 years before the coming of Christ, and it took the early church five centuries to come to a clear—albeit mysterious—understanding of the Trinity. Even now, two thousand years after Christ, we wait for his return.

In the next part, Darrel responds to Dembski’s lists of non-negotiables and clarifies how he sees BioLogos as different from “Darwinism”.

In the previous post in this series, we explored how evolution can force science into making predictions that seem counter-intuitive. For cetacean (whale) evolution, we saw that the preliminary lines of evidence (the fact that whales are vertebrates, and mammals, for instance) pointed to the prediction that modern whales are descended from four-limbed, land-dwelling ancestors. As we then noted:

Instantly this prediction raises a host of uncomfortable questions: where did their hind limbs go? How did they acquire a blowhole on the top of their heads when other mammals have two nostrils on the front of their faces? How did they transition to giving birth in the water? What happened to the teeth of the baleen whales? What happened to the hair characteristic of mammals? and so on. In some ways, evolutionary thinking about whales creates more difficulties than it appears to solve.

And yet, these difficulties are the stuff of science. If indeed our “educated guess” of terrestrial, tetrapod ancestry for whales is correct, the evidence will show that these transitions, challenging though they may seem, did indeed occur on the road to becoming “truly cetacean”.

We have already discussed hind limb and hair loss in whales, citing evidence from embryonic development in modern whales that shows how hair and hind limbs develop early in their embryogenesis, but then are lost at later stages. We now turn to one of the remaining questions: tooth loss in the lineage leading to modern toothless whales (order Mysticeti). To obtain their food these whales pass seawater through a baleen, a large sieve-like structure that filters out plankton, small fish and other food items. Some recent genetics sleuthing has investigated a portion of this riddle, and adds further details to the story of how the baleen whales came to be.

Evolution: A Theory with Bite

If indeed modern whales are descended from ancestral, four-limbed, terrestrial ancestors, then those ancestors, like mammals in general, had teeth. Modern toothed whales (order Odontoceti) have retained those teeth to the present day, but baleen whales have adopted a new way of life as filter-feeders. Researchers were curious to see if traces of a “toothed past” could be found in the genomes of modern baleen whales, so they went hunting for remnants of genes devoted to making teeth. Such defective gene remnants would be examples of pseudogenes, and we have discussed pseudogenes previously in this series. While pseudogenes in and of themselves are powerful evidence for evolution, pseudogenes that are “out of place” are especially so. One such example we have seen before is the human vitellogenin pseudogene, the remains of a gene used for yolk production in egg-laying organisms found in the exact location in the genome that evolution would predict for it. As mammals that receive embryonic nourishment through a placenta, we have no need of egg-yolk genes. Similarly, baleen whales have no need for genes responsible for making teeth, and finding the remnants of such genes would make a strong case for an evolutionary origin of baleen whales as the modified descendents of toothed whale ancestors.

Independent Lines of Evidence, but Contradictory Stories?

Some of the genes known to be used in all mammals for tooth formation were the obvious candidate genes to start with: the products of the ameloblastin, amelogenin, and enamelin genes are all used in the formation of tooth enamel, the hardest structure in the vertebrate skeleton. Researchers went looking for these genes in several Mysticete (i.e. toothless whale) species. The results showed that all the species studied did indeed have these three genes present as pseudogenes (and more specifically, as unitary pseudogenes, a special class of pseudogene we have discussed in detail previously). Finding these genes as pseudogenes in toothless whales was exactly what evolution predicted, but there was a catch: none of the mutations that removed the functions of these three genes were shared between different species, suggesting that these genes lost their function independently in the species studied. This finding was at odds with data from the fossil record, which suggested that teeth were lost only once, and early in the lineage leading to all modern toothless whales. So, the researchers seemed to have two lines of evidence that at face value contradicted each other. The fossil record suggested that tooth loss occurred once in the common ancestor of all toothless whales, but these three genes seemed to have been inactivated independently, several times over, suggesting that loss of teeth should be happening later in Mysticete evolution, and more than once.

One proposed explanation for the apparent discrepancy (among several put forward) was to predict that a fourth gene required for enamel formation was lost early in Mysticete evolution. The loss of any one gene necessary for forming enamel would be enough to prevent the process altogether. In this case, the loss of this fourth gene would prevent tooth enamel from forming, even though the genetic sequences of the other three enamel genes would still be intact. Once enamel function was lost, random mutations in the remaining enamel genes could then accumulate later in Mysticete evolution after speciation in this group was already underway. To test this hypothesis, the research group went hunting for other enamel genes in toothless whales.

Signature in the SINE

The smoking gun for tooth loss in Mysticetes turned out to be exactly what was predicted: a fourth gene, necessary for enamel production, and mutated with the same inactivating mutation in all modern toothless whales. The gene in question, named enamelysin, was destroyed when a mobile genetic element called a SINE transposon inserted into it, breaking it into two halves and removing its function:

The fact that the same SINE insertion mutation at an identical location is found in all modern Mysticete species indicates that this mutation happened once in a common ancestor and then was inherited by the entire group. Since this must have occurred early in the evolution of toothless whales in order to happen in the common ancestor of the entire group, the picture from the genetics and the fossil record match. Once again, findings in one discipline (in this case, paleontology) can be used to make very detailed predictions about what another, unrelated discipline (comparative genomics) should reveal. These results are also entirely consistent with the observation, made in the 1920s, that toothless whales form tooth buds during embryogenesis that are later reabsorbed prior to the point when the deposition of enamel would begin. As with the hind limb story in whale evolution, lines of evidence from genetics, paleontology and embryology converge to support the hypothesis that modern toothless whales descend, through modification, from toothed ancestors.

In the next post in this series, we’ll examine a few more lines of evidence for whale evolution, and extend our discussion to converging lines of evidence for the evolution of our own species.

For further reading:

Meredith, R.W., Gatesy, J., Cjeng, J., and Springer, M.S. (2011). Pseudogenization of the tooth gene enamelysin (MMP20) in the common ancestor of extant baleen whales. Proceedings of the Royal Society B: 278 (1708); 993 – 1002. Available online: http://rspb.royalsocietypublishing.org/content/early/2010/09/16/rspb.2010.1280.full.pdf

Ridewood, W.G. (1923). Observations on the skull in foetal specimens of whales of the genera Megaptera and Balaenoptera. Philosophical Transactions of the Royal Society of London B: 211; 209 - 272. Available online: http://rstb.royalsocietypublishing.org/content/211/382-390/209.full.pdf

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In our previous post, we examined processed pseudogenes – transcribed gene copies that randomly insert into genomes. Unitary pseudogenes, however, are different: unlike processed pseudogenes, they are unique sequences in genomes, and not copies. They have the features one expects of “real” genes: regulatory sequences, introns, and protein coding sections – but with mutations that prevent them from being transcribed or translated. Like buildings in various states of repair, there is a similar range for unitary pseudogenes. If they have only been recently inactivated, they will be largely intact – like a recently abandoned building with a few broken windows. Others are further along in their degradation, like a stone building without a roof and grass growing up through the floor. Some are so far gone that one needs to peel back the turf to search for what remains of the foundation. Despite their various states of disrepair, they remain recognizable – in some cases, they can persist for millions of years before they slowly mutate beyond recognition.

The reason for these defective genes is straightforward: the organism that had the original mutation that removed the function of the gene was not significantly impacted by the loss. One example I have previously discussed is the human GLO pseudogene. The functional GLO gene is part of the biochemical pathway for making vitamin C, something that humans and other primates are not able to do: if we don’t get enough in our diet, we get scurvy. In an environment with adequate dietary vitamin C, however, the loss of the GLO gene is no big deal – and mutations that remove its function would not have been a disadvantage. The mutations that remove GLO function in humans are the same mutations we see in other species – they are an example of mutations in a nested hierarchy, the type of pattern that relatedness produces. This indicates that the mutations happened once, in a common ancestral species, and have been inherited by several species that descend from that ancestor, ours included.

So, what’s a defective gene like you doing in a species like this?

While it makes sense that mammals ought to be able to make vitamin C (even if humans and other primates cannot), in some cases pseudogenes seem much more “out of place.” One example from the human genome that we have discussed in the past, is the vitellogenin gene, a gene required for egg yolk formation in egg-laying organisms. This gene is present in the human genome as a pseudogene, even though humans are placental mammals – human embryos are nourished through a placenta, not egg yolk. This pseudogene was located in the human genome by predicting that its genomic location relative to its neighboring genes would be retained for a long time, even after its inactivation. Accordingly, researchers found a functional vitellogenin gene in the chicken genome, and noted the genes on either side of it (let’s just call them “Gene A and Gene B” for convenience). Gene A and Gene B are also side by side in the human genome, so the researchers looked between them for the signs of vitellogenin gene remains – and found them in that precise spot, still visible despite approximately 300 million years since we last shared a common ancestor with chickens:

Other examples like this abound: whales, for example, have unitary pseudogene remnants of genes devoted to an air-based sense of smell, even in cases where the whale species in question does not have an olfactory organ. A second example from whales are pseudogene remnants of visual pigments adapted for wavelengths of light found in terrestrial settings, not aquatic environments. These examples make perfect sense in light of the terrestrial ancestry of whales, but are challenging to account for from an antievolutionary perspective.

Pseudogenes: evolution’s silver bullet?

Unitary pseudogenes with shared mutations in nested hierarchies among related species are far from the only evidence for evolution, and are not even necessarily the line of evidence most convincing to specialists. Specialists can see the broad pattern of multiple lines of converging evidence that support common ancestry to an extent non-specialists cannot easily appreciate. Unitary pseudogenes, however, are valuable tools for demonstrating a sampling of those lines of evidence, and providing a window into the world of comparative genomics that, to paraphrase Dobzhansky’s famous quote, would make absolutely no sense except in the light of evolution.

Yes, the implications of unitary pseudogenes such as these are easy for even non-specialists to grasp: whales have the defective remnants of genes adapted to terrestrial vision and air-based smelling because they descend from terrestrial ancestors. Placental mammals, including humans, have a defective remnant of a gene used to make egg yolk because they descend from egg-laying ancestors. Unitary pseudogenes share identical mutations across related species because they were inactivated in a common ancestor, and were inherited by every species that descended from that ancestral species.

No special training in genetics is required to appreciate the strength of the evidence that these examples provide. Nor does it require special insight to see that attempts made by antievolutionary groups to refute this evidence face an uphill battle. Its daunting nature notwithstanding, some have undertaken just that task, since the evidence is too compelling to ignore, and too risky to leave unanswered.

Bringing it together: antievolutionary approaches to pseudogenes, unitary and otherwise, miss the mark

Now that we have covered significant ground with respect to what various classes of pseudogenes are and how they arise, we are now able to properly evaluate antievolutionary arguments put forward in an attempt to discredit these lines of evidence for evolution. Attempts to discredit unitary pseudogene evidence generally have one or both of the following two approaches, which we will evaluate in turn:

Approach 1: Discuss rare examples of processed pseudogenes that have acquired function, and imply that all pseudogenes, including unitary pseudogenes, will similarly be shown to have function.

This approach is a fairly common one in the antievolutionary literature, and examples abound. We have examined previously how processed pseudogenes may, in rare cases, acquire a function and come under selection. Note well: the vast, vast majority of processed pseudogenes are not functional and are slowly mutating beyond recognition as DNA not under selection. While rare examples that have acquired function are very interesting from a scientific perspective, they do not “confer functionality” on the remainder of processed pseudogenes, let alone on unitary pseudogenes.

The other issue with this argument is that in many cases we know what the function of the unitary pseudogene once was. We know what the function of vitellogenin is, for example – and we can find this gene in modern-day egg-laying animals. When we see the remnants of this sequence in the human genome it is a stretch to argue that it has another, as of yet unknown function. When we see the human pseudogene sitting between two other genes in the human genome the same order as we observe in the chicken genome, it stretches credibility well past the breaking point.

Approach 2: Claim that unitary pseudogenes with mutations shared across species are the result of non-random mutations that occurred independently in the two species, and are not inherited from a common ancestor.

This argument, though having an appearance of validity, is similarly doomed to frustration. While mutations are not entirely random (certain regions of the genome mutate more readily than others) there is no known mechanism that could create the precise, repeated pattern of shared mutations we observe between related species. The most significant attempt to mount this type of argument against unitary pseudogenes in general was directed at the GLO pseudogene, and I have already discussed the specific details of why that attempt was inadequate. No refinement of that argument, to my knowledge, has been put forward since.

In summary, pseudogenes in general, and unitary pseudogenes in particular, remain a significant thorn in the side of antievolutionary groups. In the next post in this series, we’ll cast our net wider and explore an example of how multiple, convergent lines of evidence support evolution, often in unexpected ways.

For further reading:

http://biologos.org/blog/signature-in-the-pseudogenes-part-1
http://biologos.org/blog/signature-in-the-pseudogenes-part-2
http://biologos.org/blog/a-tale-of-three-creationists-part-3