That said, I genuinely empathize with those who are reluctant to abandon traditional theological concepts for newer, still- developing ones. Given spiritual leaders’ biblical mandate to protect their families and congregations against error, a responsibility for which God will hold them strictly accountable (James 3:1), I respect their refusal to expose their flock to ideologies they regard as conflicting with the Word of God.

I further understand pastors and theologians’ resistance to tethering theology—which is meant to provide a solid epistemological foundation—too closely to that intrinsically dynamic endeavor called science. All humans need ideological stability, perhaps especially so with respect to spiritual matters. Recognizing this, pastors rightly ask why they should abandon or substantially revise an internally-consistent systematic theology that has served the church with relative stability for many hundreds of years. Science, on the other hand, is a realm for adventurers, groundbreakers, and ideological athletes intent on not just polishing or expanding today’s body of knowledge, but shattering it when necessary. Resounding with the jousts and clashes of competing ideas and arguments, and the stunning reversals of ideas once widely held, science often appears to be a messy–even tumultuous–business. Spiritual shepherds are insistent that the epistemological dynamism that necessarily characterizes science never become the mainstay of the Christian experience, which must be fundamentally stable and dependable. They see wisdom in maintaining a safe distance between the Church and the choppy waters of science.

The question, then, is whether the waters of scientific thought, particularly with respect to the age of the earth and evolution, have sufficiently smoothed out to warrant conservative thinkers’ taking a deeper look. Of course, the catch-22 here is that this can’t be answered without actually embarking upon an expedition of exploration and investigation, much as I recently did. Once undertaken, however, the conservative explorer will likely be confronted by a formidable problem:

As I can personally attest, navigating the crowded forum of wildly-differing ideas as to how to resolve the faith-science divide can be terribly daunting. Making this especially disconcerting for the conservative is the sobering reality that amidst the chorus of conflicting theories, one finds very little substantive published input from respected conservative theologians. As a result, the conservative seeker is sure to find herself awash in an ocean of seemingly novel theological “solutions” that are fundamentally antithetical to her evangelical sensibilities. This is likely to result in the impression that there is in fact no way to reconcile the findings of modern science with the key doctrines of orthodox Christianity, and hence the termination of the endeavor. Not only was this dynamic a constant challenge to me, but has proved a stumbling block to many would-be seekers that I personally know.

Whence then change? I believe the breakthrough will begin with a particular subgroup of conservative evangelical pastors, elders, and theologians. I know firsthand that there are many who, truth be told, have not been entirely at peace with their fellow conservatives’ summary rejection of—and apologias against—the findings of mainstream science. They have a gnawing sense that devastation looms for the Church and her children unless detachment yields to engagement, and rhetoric to substance. These have likely admitted to themselves that despite stridently asserting anti-evolution/old-earth views, they actually don’t understand these views in depth (nearly every conservative pastor and elder I’ve spoken with has conceded this). To date, these shepherds and thinkers have remained silent about their misgivings, reluctant to be perceived by their congregations and peers as betraying true Christianity. Given the astonishing fruitfulness of modern science and the comparative barrenness of young-earth creationism, I believe these evangelical leaders may now finally regard themselves as justified in stepping forward and publicly questioning whether the latter is in fact the view that a truth-revealing God would have His people believe.

Indeed, if I may, I would exhort these, my fellow conservative evangelical shepherds and thinkers, to set aside all reticence and fear, emerge from anonymity, and storm the forum of discourse, engaging this most pressing matter with vigor, equanimity, and humility. In doing so, know upfront that there will be few handrails to guide; you will not be building upon an extensive precedence of published conservative thought. Rather, you will be pioneers, with the open prairie of contemplation and consideration before you and the Word of God as a faithful, orienting star. The journey will be at times confounding, often scary, and never without challenge. Yet only through such robust, self-critical analysis will you find yourself in a posture where God can correct and refine all that He would, and only after which will you be able to pass on to your flocks a cogent, truly harmonious portrait of our Lord and His Creation that finds rich consistency between His written and natural revelations. I firmly believe that the fuller, more deeply informed portrait of the Lord and His universe that emerges from this investigation will fill your congregations with an unprecedented new sense of awe at our beloved God as Creator, and profoundly enhance their worship of Him. This has certainly been the result of my own journey.

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.

Transitional Fossils

Some time ago, the Discovery Institute’s Casey Luskin commented on the human origins exhibit at the Smithsonian Institution, suggesting that palaeoanthropologists use evolutionary theory to describe the progression of the human lineage even when they don’t have transitional fossils with which to work. He writes:

What's ironic, however, is that if you ask the question How Do We Know Humans Evolved? the answer you’re given is, “Fossils like the ones shown in our Human Fossils Gallery provide evidence that modern humans evolved from earlier humans.” So whether you find fossils or you don’t, that’s evidence for evolution.

Indeed, it has become an article of faith for those espousing both the young earth creation (hereafter YEC) model and many who hold to the intelligent design model that transitional fossils do not exist and therefore evolution has not taken place. Support for this position usually entails attacking the weak areas of the fossil record, where burial processes have left us little with which to work, or the creation of straw men arguments in which transitional fossils are defined in such a way that none could ever be found. Often this centers on the concept of “missing link,” a term that is habitually used in the popular press and young earth creation and intelligent design literature when referring to fossil remains but which has little to no meaning for biologists or palaeontologists. As Ahlberg and Clack (Ahlberg and Clack 2006) write:

But the concept has become freighted with unfounded notions of evolutionary ‘progress’ and with a mistaken emphasis on the single intermediate fossil as the key to understanding evolutionary transitions. Much of the importance of transitional fossils actually lies in how they resemble and differ from their nearest neighbours in the phylogenetic tree, and in the picture of change that emerges from this pattern.

Contrary to common misconceptions, the fossil record does not record one single lineage for any family of organisms but rather a series of branches, with many related species coexisting synchronously. Darwin hypothesized that the evolutionary record reflected this bushiness and drew such a diagram in his journal. At the time, though, he had little in the way of fossil evidence to back up this position. Much has changed since his day.

An analogy for understanding this “bushiness” was best described by Prothero and Buell (Prothero and Buell 2007). They suggest that the reader consider his or her own genealogy. You and your siblings are the direct descendents of your parents and, while you are similar to them, each of you has different characteristics not shared with them as well as characteristics that you do share. Your parents have siblings as well (your aunts and uncles), and your grandparents are their last common ancestors. These siblings have their own children (your cousins), who have different and similar traits relative to their parents. They are broadly recognizable as being related to you (“oh, I see you have Aunt Edna’s nose”) but three or four generations out, they will become less and less so. These are the “nearest neighbours” that Ahlberg and Clack describe. In this analogy, each of these cousins represents a transitional form from what was (your grandparents) to what will be down the road.

For example, no one would confuse a frog with a salamander but if you trace the fossil record of each back in time, eventually you encounter a fossil, Gerobatrachus hottoni which was recently discovered (Anderson et al. 2008) that is best described as a “frogamander,” having the basal characteristics of both frogs and salamanders. Had we seen such an animal at the time, it is likely we would not have found it remarkable because it would have resembled the species around it. One lineage eventually diverged into frogs, salamanders and other amphibians. Most (just like Darwin proposed in his tree diagram with the little hatch marks at the tip of many branches) went extinct.

Taxonomy and the Beginnings of Human Origins

All life is classified based on a system devised by Carolus Linneaus in 1735 in his remarkable work Systema Naturae. This system gives all recognized species an individual place based on a system of hierarchy. The study of classification is known as taxonomy. A taxonomic ranking for humans would be this:

When a fossil is excavated, the first thing that the palaeontologist does is make a taxonomic assessment of where it fits in a sequence of known fossils. Traits that are shared with other like species or genera are referred to as primitive traits. Examples of this in humans are five fingers and the presence of three arm bones. We share this with all mammals. Traits that are new or are not shared with other like species are referred to as derived traits. Examples of this in humans are the skeletal changes in the pelvis and the foot to allow for walking upright. We do not share these with any other primates.

Transitional fossils in the human fossil record are distinguished at both the genus and species level. This group includes the extinct genera Ardipithecus and Australopithecus and the current genus Homo. All species except Homo sapiens are extinct. Much of the recent study of early humans focuses on the transition from Ardipithecus (‘Ardi’) to Australopithecus (‘Lucy’ and similar fossils) and from Australopithecus to Homo, the genus that led eventually to us. While each of the australopithecine species identified in the fossil record has derived characteristics that separate them from their ancestors and from each other, only one led to the genus Homo.

In future posts, I will describe the evidence for human evolution and why this evidence is compelling. It suggests that we have had a long, varied history filled with great leaps of change, crushing defeat, and eventual expansion into all areas of the globe.

Notes

Ahlberg, P. & J. Clack (2006) A firm step from water to land. Nature, 440.

Anderson, J. S., R. R. Reisz, D. Scott, N. B. Frobisch & S. S. Sumida (2008) A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. Nature, 453, 515-518.

Prothero, D. & C. Buell. 2007. Evolution: What the fossils say and why it matters. Columbia Univ Pr.

Introduction

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

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

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

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

Theology of the cross

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

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

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

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

Why is evolution so disconcerting to Christians?

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

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

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

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

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

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

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

The crucifixion is disconcerting too

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

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

Redemption extends to all of creation

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

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

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

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

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

Conclusion

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

Explore this Topic Further

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

Notes

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

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

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

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

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

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

Interpretive communities

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

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

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

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

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

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

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

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

New eyes, fresh air

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

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

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

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

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

Notes

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

In Part 2 of this series, we concluded by noting that, as Christian geologists willing to consider the possibility, we find no compelling evidence that the earth’s geological features can be explained by a global Flood. Here we consider three lines of evidence: global salt deposits, the order of deposition of sediment layers in the Grand Canyon, and the sequence of fossils in geological strata.

Salt Deposits

There are many places around the earth with layers of salt, some thousands of feet in thickness. Just off the southern coast of the United States in the Gulf of Mexico, thick salt deposits sit beneath thousands of feet of sediment (Fig. 1). These deposits lie within the layers that are said to have been deposited by the Flood.

We understand how salt beds form. At locations such as the Bonneville Salt Flats of Utah, or at the Dead Sea at the border of Israel and Jordan, salt is actively forming. Salt beds form when water is evaporated. During evaporation, the concentration of dissolved ions increases until the water cannot hold the salt in solution anymore and mineral salt begins to form. If a presently unknown or poorly understood process could produce salt without evaporation, as argued by young-earth advocates¹, it would quickly dissolve as soon as it came into contact with flood water, just as the salt from your saltshaker rapidly dissolves when added to water or moist food.

One might argue that the waters from the Flood could have evaporated to leave behind the salt deposits we see today, but there is a serious problem. The thousands of feet of sediment on top of the salt is also said to be from the Flood, meaning the flood waters cannot have evaporated to produce the salt and still be present and violent enough to transport thousands of feet of sediment to the same location. In other words, a single flood cannot be called upon to explain both the salt and the overlying sediment. For those who wish to argue that natural processes could have been vastly different during the Flood, there are at least two replies. First, under such a scenario, there is no point in Flood Geology studies any more than in normal studies, for nothing could be gained by the study of unknowable processes. A more important question, however, would be to ask why God would alter natural processes just to make Flood sediments look like they are not flood sediments. What would the purpose be? (We will revisit this thought later.)

Grand Canyon: Order of Deposition

The Grand Canyon is made up of a sequence of layers that defies any reasonable attempt to explain by a single flood. The alternating layers of limestone, sandstone and shale each form in unique environments. If these deposits were formed at different times under various sea-level stages, it is quite simple to explain the different grain sizes and rock types as a function of depth and distance from the shore line. If explained with a single catastrophic flood that abided by God’s natural laws of physics and chemistry, logic must be stretched beyond the breaking point.

As a very simple observation, consider instructions given in virtually every gardening book. A good soil will have a mix of sand, silt and clay. To determine the quality of your soil, you take a handful or two, put it in a clear container, add water and shake it up. When you stop shaking, the coarse grained material will settle out first resulting in a sequence of layers: sand on the bottom, then silt, then clay. You can readily see how much of each you have by the thickness of each layer.

This is informative of what we see in flood deposits. As moving flood waters slow down, finer and finer grained sediment settles out resulting in a “fining upward” sequence. If most of the Grand Canyon layers were laid down by the Flood, then we should see the same thing – a “fining upward” sequence. Instead, we see a series of alternating layers of fine and coarse grained material, with smaller-scale alternating layers within the larger ones (Fig. 2). Increasing the violence of a flood does nothing to negate the standard order of deposition. Repeated surging of flood waters across the surface likewise offers little explanatory power; in this case we might expect successive layers, each with their own “fining upward” sequence, but such is not what is observed. Further, the Grand Canyon includes multiple layers of limestone, which are never found in flood deposits of any magnitude. Even in floods as massive as one thought to have catastrophically deluged the once dry Mediterranean Sea basin with thousands of feet of water – limestone beds are conspicuously absent.

Fossil Sequence

If a massive flood were responsible for the fossil record, what would we expect to see? If the Flood was violent enough to rip chunks of rock up from the earth and move entire continents (standard Young Earth claims)², then it should be obvious that life forms from every imaginable niche would be tumbled and mixed together (Fig. 3a). We should find numerous examples of mammoths mixed with triceratops, and pterodactyls mixed with sparrows. Ferns and meadow flowers should be found in the same deposits, along with trilobites and whales. Further, we should find all major life forms still living today, for Genesis 7:8-9 is clear in stating that all terrestrial animals were preserved on the ark.

What we actually observe is far different (Fig. 3b). There is an orderly sequence where trilobites only occur in very old rocks, dinosaurs in later beds, and mammoths in still later layers. Organisms like flowers and ferns are present together in more recent deposits, but only ferns with no flowers are found in older deposits. Some readers will recognize this as an example from the “geologic column” and be tempted to discount it as a fabrication. For those thinking this way, consider what Henry Morris had to say in both editions of Scientific Creationism:

“Creationists do not question the general validity of the geologic column, however, at least as an indicator of the usual order of deposition of the fossils…”⁵

If we revisit the Grand Canyon for a moment, is it not striking that there is not a single dinosaur, mammoth or bird in the entire exposed sequence? Not one. To find these, you have to go to younger sediments found in deposits outside the canyon that have not been fully eroded away yet. How could such a lack of mixing be possible if the Flood was violent enough to move continents?

For more, be sure to read our FAQs How are the ages of the Earth and universe calculated? and What scientific evidence do we have about the first humans?, as well as our recent infographic How Do We Know the Earth is Old?.

Author's Note from Joy Walters

As I mentioned in my first post, I grew up skeptical of the whole idea of evolution. One contributor to my disbelief was the lengthy timescale for the “tree of life” that was presented with the theory. I would hear, for example, that dinosaurs lived hundreds of millions of years ago, but there was no explanation of why this was true; it was just given as a fact. No one explained the methods of dating, and so I thought biologists simply estimated the ages of species to fit their preconceived notions of how long it would take for one species to emerge from another. It also seemed like the ages were periodically revised and extended farther back in time, and I figured scientists needed to manipulate numbers to make evolution plausible. This, in my mind, made the theory both unbelievable and dismissible.

Once I learned about the techniques used to date fossils, I realized that my first impressions were wrong; the ancient ages of species are scientific determinations rather than scholarly conjectures. However, I have found in recent conversations that Christians remain skeptical of old ages and the evolutionary time scale. For this reason, I wanted the videocast to address the process of fossil dating (what the methods are and why they are accurate) while focusing on cases where hominid fossils were discovered and dated using these very methods. My hope is that Believers would be informed about the evidence for human evolution and its scientific grounding.

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

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

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

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

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

I am using the term in the same sense. Like Ramm, I don’t regard theistic evolution as a concordist view, even though some TE proponents like to say that evolution can be “harmonized” with Genesis. At the same time, Ramm completely rejected Price’s recent creation and Flood Geology, and he obviously did not consider that view to be a type of concordism either. Why not? On first glance, the YEC view might seem to fall within Ramm’s definition of concordism, and the authors of one of the books recommended in the first column in this series classify it as a type of concordism. However, the harmony sought by YEC proponents comes at the cost of entirely rejecting the standard geologic record, which they replace with Flood Geology. That isn’t what Ramm had in mind by seeking a “harmony.”

Often the concordist view is called “progressive creation,” another term that Ramm used with much approval: “We believe that the fundamental pattern of creation is progressive creation,” he wrote prominently in italics. Indeed, it is sometimes assumed that Ramm invented both terms, “concordism” and “progressive creation,” when in fact he did no such thing. If anything, the latter term is even older than the former, having been used to refer to an OEC interpretation of natural history for about two centuries. The first American author to use it may have been Benjamin Silliman, an evangelical who was appointed the first professor of natural history at Yale by another evangelical, Yale’s president Timothy Dwight. Silliman was the single most influential figure in American science during the nineteenth century. In his Outline of the Course of Geological Lectures Given in Yale College (1829), Silliman spoke of “the progressive creation, life, death and sepulture [fossilization], of animals and plants.” On another occasion he noted how the Bible describes “a successive creation of plants and animals, ending with man,” and that geology “proves this history to be true.”

Clearly, then, the concordist or progressive creationist view has been around for a long time. Let’s examine its main components.

Core Tenets or Assumptions of Concordism

(1) The Bible and science (mainly geology and astronomy) are BOTH reliable sources of knowledge about the origin of the earth and the universe. God has written two “books” for our instruction, the book of nature and the book of scripture. Since God is the author of both “books,” they must agree when properly interpreted.

If this strikes you as worded deliberately to sound like Galileo, you’re right—but only because so many proponents of the concordist view also have Galileo very much in their minds. The basic scheme is neatly depicted in this diagram:

Recall Galileo’s belief that the book of nature, written in the divine and unambiguous language of mathematics, should be used to help interpret the book of scripture, written in the richer but more ambiguous language spoken by the ordinary persons for whom its vital message of salvation was intended. When they accept the evidence for an ancient earth, Silliman and many other evangelical scholars right down to our own day believe they have merely applied Galileo’s logic to a different set of biblical texts.

(2) Scientific evidence, when properly interpreted, is consistent with the Bible, when properly interpreted.

Galileo again: because both “books” are written by the same Author, they must agree. As he said in his Letter to Christina, “the holy Bible can never speak untruth—whenever its true meaning is understood. But I believe nobody will deny that it is often very abstruse, and may say things which are quite different from what its bare words signify. Hence in expounding the Bible if one were always to confine oneself to the unadorned grammatical meaning, one might fall into error.”

What about those who interpret the book of nature? Can they ever be mistaken? Should they ever yield to those who interpret the book of scripture? Evolution was not the source of Galileo’s concerns, but concordists today would give the nod to scripture mainly when it comes to evolution—especially human evolution. Regardless of how much evolution they accept for other organisms, concordists hold strongly to the separate creation of Adam and Eve as the first human beings. They believe that Genesis 1 was intended to be at least broadly historical, even though it does not provide detailed scientific information.

Mainstream conclusions in geology and cosmology, however, are almost always accepted; indeed, Hugh Ross and some other OECs not only accept the “big bang” theory of the universe, they actively promote it as central to Christian apologetics, because it presents us with a universe that is not eternal and that appears to be exquisitely designed as a home for living creatures, including ourselves.

(3) The Bible does NOT tell us the age of the earth.

Two main concordist approaches to resolving the tension between Genesis and scientific dating of the earth have been popular since the mid-nineteenth century: the “day-age theory,” which still has numerous advocates (including Ross), and the “gap theory,” which is now nearly extinct. One hundred years ago, however, the gap theory was probably the more popular option among conservative Protestants, and it remained so until the 1960s and 1970s, when the rapid spread of Scientific Creationism all but relegated the gap view to the dust bin.

The Gap Theory

The gap theory posits a “gap” of untold length between “the beginning” of Genesis 1:1 and the first “day” of creation, starting with Genesis 1:3; the formless void of Gen 1:2 corresponds to this “gap.” Verse 1 refers to the original creation of the earth and the universe “in the beginning,” not to world as we now find it. The fossils represent creatures that populated the original creation. Current living creatures come from a second creation, after the “gap,” when God made them in six literal days, culminating in the creation of Adam and Eve just a few thousand years ago.

Although the creation of humanity matches the traditional biblical chronology—a major reason for the popularity of the gap theory in its heyday—the original creation cannot be dated from the Bible. Whether it happened 100 million years ago (as scientists thought around 1900) or billions of years ago (as scientists thought for much of the twentieth century), does not matter one bit to the Bible. Geologists can say whatever they wish about the age of the earth. The Scofield Reference Bible, originally published by Oxford University Press in 1909, taught the gap theory to generations of conservative Protestants in the English speaking world. The headings alone indicate Scofield’s endorsement of the gap theory, and he waited no longer than the second footnote to spell it out: “The first creative act refers to the dateless past, and gives scope for all the geologic ages.” (NOTE: the date “B.C. 4004" in the middle column refers to the start of the six days, not to “the beginning.” I’ll elaborate on that date in part two of this column.)

As Scofield’s third note shows, the gap theory was usually placed within an elaborate theological structure about the fall of Satan and the angels, based on certain prophetic texts (see below). A full discussion would take us far afield, but something should be said about how gap theorists interpret Genesis 1:2, the crucial verse for their model. Scofield sticks with the King James Version, “the earth was without form, and void,” doing the exegetical work in his notes, but others like to render it as, “the earth became a waste place,”, drawing out the implication (in their view) that God destroyed the original creation, laying waste to it in an act of judgment, leaving us with fossils of the pre-Adamic world.

In some versions of the gap view, the original creation included pre-Adamite people—that is, humans who were not descended from Adam and Eve. This idea that took many forms, some with racist overtones. Perhaps this strikes you as a bit surprising, but in the mid-nineteenth century it was a commonplace conception among Protestants, and not unknown to Catholics either. A prominent example would be The Pre-Adamite Earth: A Contribution to Theological Science (1846), a very popular book by the English Congregational minister John Harris. Historian David Livingstone has written the definitive history of this fascinating idea. For more, see this interview, but there is no substitute for reading the book itself! Let me make an invitation: who wants to borrow a copy and provide their own commentary here?

In all versions of the gap theory, however, fossils are vestiges of the pre-Adamic world, produced when it was destroyed; they are not a record of evolutionary history. All modern animals and many plants were created recently, in six literal days. Despite what YECs often say, there is just no way to see the gap theory as an “evolutionist” interpretation of Genesis!

The "Day-Age" Theory

The day-age theory takes the “days” in Genesis 1 as periods of indefinite length, such that neither the age of the earth nor the duration of any particular period in creation history can be determined from the Bible. The basis for this view is that the Hebrew word “yom” (day) can also mean an indefinite period of time. According to Hugh Ross, the leading advocate of progressive creation today, if the Hebrews had wanted to refer to a long period of indefinite length, they would have used the word “yom.” Thus, he claims to be giving a literal interpretation when he upholds the day-age view.

Numerous varieties of the day-age view have been proposed since the eighteenth century, too many to review here. They all teach that the major kinds of plants and animals were created separately, over the eons of earth history; the fossil record shows reliably which came earlier and which came later. Thus, the creation was accomplished “progressively,” as Silliman held in 1829 and Ross holds today. Ross thinks God performed millions of acts of special creation, but concordists differ substantially among themselves on the magnitude of the number for this.

Concordists mostly agree, however, that the first true humans were Adam and Eve, and that they were created ex nihilo—but, how recently were they created? Can the biblical 6,000 years be stretched far enough to encompass fossils of modern humans (homo sapiens sapiens) dating back perhaps to nearly 200,000 years? Can the biblical picture of Adam’s children living amidst cities and agriculture be reconciled with extensive evidence of humans who lived long before either existed? I’m no anthropologist, but anyone can see the relevance of such questions for this position.

(4) The Flood was a real historical event, but it was not responsible for producing the fossils; rather, fossils are relics of organisms that were mainly here before humans.

The last of the four basic assumptions shared by concordists is that they reject Flood Geology and accept the standard geologic column. Hugh Ross and some others believe that the flood was geographically localized, covering part of the ancient Near East but not the whole globe. This is called the “local flood” view. Biblical scholar Paul Seely briefly assesses this view in light of current knowledge here, but a full discussion of the issues goes well beyond of the scope of this online course. Anyone with appropriate expertise is invited to place comments below. The main point is that the flood has no geological significance for concordists, whether or not it was geographically “local.”

Looking Ahead

Our look at concordism concludes on July 3 with some conclusions about the OEC view and further historical comments. I’ll pay attention to your comments in the meantime.

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.

Today's video is courtesy of filmmaker Ryan Pettey, director/editor of Satellite Pictures and features physicist Ard Louis.

In today's video, Oxford physicist Ard Louis discusses the famous debate between renowned evolutionary biologists Stephen Jay Gould and Simon Conway Morris. Gould believed (and wrote in his book Wonderful Life) that if the "tape" of evolution were rerun, the chance that anything like human intelligence would emerge is essentially zero. In other words, humanity is here through random accident. Gould pointed to the work of Morris and fellow scientists in their research of the Burgess Shale as evidence for this view.

However, Morris himself disagrees, pointing to what is called evolutionary convergence. As Morris notes, there are numerous examples of identical features evolving multiple times throughout the history of life independently. Morris believes that if the tape of life were replayed, we would see something like humans emerge. A Christian might say, it looks like we were planned.

Some Christians might find Simon Conway Morris' viewpoint, with its implicit teleology, more attractive. Others, perhaps motivated by a high view of providence, may find Gould's emphasis on contingency equally congenial to their faith. What do you think?

In our previous essay, we learned that a tree summarizing species relationships can be built using DNA information, and how we can use DNA as a “molecular clock” to date ancient events. Both of these methods have made specific predictions about the origin of whales. If evolution is true: whales are related to the even-toed hoofed mammals and should share common ancestors with them; transitional fossil forms dating from about 45 to 50 million years ago should be found which can be shown to be related to both the even-toed hoofed mammals and modern whales; whales are most closely related to modern hippos, and should share a common ancestor with them.

What other types of information might we be able to use to construct a phylogenetic tree (i.e. a family tree) of species relationships? It turns out that characteristics of body structure also can be used – for example, the presence or absence of certain bones, or the specific shapes of those bones. An advantage of using bony features is that they can be recovered from fossils, whereas DNA (with only certain limited exceptions) must come from living organisms.

We can also derive functional information from an examination of bony features. The various protrusions, bumps and knobs found on bones usually have important implications. For example, smooth rounded areas at the ends of bones allow them to fit together and move easily. The shapes of such surfaces determine which bone motions are “allowed” or “disallowed”. Consider, for example, the motion of the forearm against the upper arm at the elbow. This is a “hinge” joint, whose normal motion is defined by the shapes of the upper arm bone and one of the forearm bones, where they meet each other. You might normally exercise the action of this hinge joint when you pick up a cup of coffee, bring it to your mouth, then set it back down again. Let’s try to imagine another motion. For this exercise we first need to get our arm into the proper starting position. Place your arm at your side, bent at the elbow at a ninety degree angle, with your palm up. Now, while keeping your palm up, let’s attempt to move your arm only at the elbow (no shoulder motion – that’s cheating!). Now swing your forearm out to the side and attempt to end up with your fingers pointed directly away from your side. Most of you will not be able to do this. If you can, it’s because your shoulder is rotating in spite of yourself. This motion at the elbow is normally not allowed. Hence a careful analysis of bone shapes can allow us to infer how the bones were used. This in turn can assist us in the task of phylogenetic (evolutionary) classification of organisms. That is, we will have more confidence in the grouping together of animals in our tree diagram if corresponding bones are used functionally in the same way.

Therefore we would expect that we could use various bony features to help us examine the predictions generated by our previous look at different types of DNA data. Are there any bony features that are particularly relevant to the even-toed hoofed mammals? Well, it turns out that there are. These are mainly running animals, and there are several features of their ankle bones, which taken together define the “allowed” motions which make them efficient runners. If one takes the various ankle bones of a large group of mammals, examines them carefully to note their shapes, scores that information into a table, then uses a computer program to build a phylogenetic tree, it turns out that all the even-toed hoofed mammals are placed together. So far, so good. But what about whales? Well, now we have an obvious problem. Modern whales are very specialized, - they have flippers which correspond to the forelimbs, and they have almost no hind limbs! I say “almost” because they do have small pelvic bones, which are not attached to the rest of their skeletons. But they certainly have no ankles. This is where the fossils should come in – if evolution is true, we should expect to be able to identify transitional fossils which are ancestral to whales which contain the characteristic ankle bony features of the even-toed hoofed mammals.

Now let’s look at bony features from the whale perspective. We have already mentioned the almost complete loss of hind limbs, and the presence of forelimbs modified into flippers. In addition, as air breathers, whales have a blowhole at the top of their skull. And as powerful swimmers, which use a large tail fluke in vertical motions, whales have enormous sets of muscles which attach to enlarged projections from their vertebral column. So if evolution is true, we should begin to see fossil forms which manifest changes in bony features which correspond to the gradual accumulation of these whale-like characteristics. However, we still need more, because these various bony features all would be expected to occur in largely or exclusively aquatic forms. We might expect this to correspond to the later stages of a transition from terrestrial even-toed hoofed mammals. But what about the earlier stages? It would be very helpful if we had some “defining” characteristic of whales, similar to the ankle structure of even-toed hoofed mammals.

It turns out that the structure of the bones of the skull and ear apparatus of whales are highly modified to allow efficient hearing underwater. The mechanical aspects of efficiently receiving sound through water are somewhat different than receiving sound travelling through air. If evolution is true, we should expect to be able to find key transitional fossil forms with a progressive series of modifications of the skull and ear bones, features which would not be found in any other mammals.

Now that we know what we should expect to see, if evolution is true, let’s look at what has actually been found in the fossil record. Over the last fifteen years or so, a series of fossils, many of them discovered in the Indian subcontinent, have fulfilled nearly all of our predictions.^1,2 Let’s look at the figure below (Figure 1), reproduced from a recent popular book on evolution.³ This shows a series of fossils, arranged in approximate chronological order, with a modern whale at the top. How old are these fossil forms? The entire fossil progression illustrated occurs from a little over 50 million years ago to about 40 million years ago. So a remarkable alteration in general body form occurred in a little over 10 million years. This time frame agrees well with the previous prediction from the DNA “clock” that we discussed in our previous essay. Second, the general change in body shape corresponds to what we predicted in our discussion of whale bony features above. That is, there is a gradual elongation and streamlining, there is a modification of the forelimb into flippers and progressive reduction of the hindlimb, the nostrils for breathing move toward the top of the skull to form a blowhole (not obvious from the diagram), and the vertebrae develop enlarged projections to support the attachment of swimming muscles.

Figure 1: Skeletons and Body Forms of Modern Whales and Fossil Ancestors
The reconstructed skeletons (black) from modern whales (top) and various ancestral skeletal forms (series below) are in chronological order (from Pakicetus up). Indohyus is an extinct whale “cousin”. Relative body size, to scale, is indicated by the gray shapes at the right of each animal.

There is probably little question that the last fossil species in the figure (Durodon) is well on the way to becoming a modern whale. However, it might be argued by a skeptic that the earlier species (like Rhodocetus, Ambulocetus, or Pakicetus), despite the “cetus” (whale) part of their names, are not so obviously “whale-like” that they deserve to be considered as fossil whale ancestors. However, remember the characteristic whale skull modifications for hearing? It has been shown very clearly that throughout this series of fossil species, the various bony changes necessary to support efficient hearing in water were being acquired in a stepwise fashion. Organisms earlier in the sequence had skeletal characteristics consistent with them being able to hear well in both air (using the “classic” mammalian hearing apparatus), and newly acquired changes to also allow better hearing in water. Later organisms in the sequence become increasingly specialized for hearing in water only.⁴

What of the earliest fossil shown in this diagram –Pakicetus? Careful examination shows that it has the features we would predict for an early whale ancestor. It has the ankle bone characteristics of the even-toed hoofed mammals (in fact these features are also found in several of the later fossil forms as well, ensuring their continuity). This confirms one of the predictions made by the DNA evidence we discussed earlier. Furthermore, it has some of the modifications of the skull bones necessary for more efficient underwater hearing, which were previously documented only for modern whales and their later (more obvious) ancestors.⁴ These features are also shared with the “whale cousin” Indohyus.⁵ Preservation of more of the skeleton of this latter species has allowed detailed analysis indicating characteristics likely shared with whale ancestors. Indohyus was probably a wading animal, which spent much of its time in the water. It appears to have fed mostly on land, so it is suggested that resort to the water was made to escape predators.⁵

Finally, we need to look back at the last prediction from our previous DNA evidence, namely that modern whales are most closely related to hippos. If evolution is true, we should expect to find fossil forms linking these two modern groups. This has proven to be a tougher nut to crack, mainly because the ancestral whales first appear about 50 million years ago in what is now south Asia, and the hippo family first appears about 15 million years ago, in Africa. The most recent tree diagram, produced by using a combination of skeletal features and DNA data, still supports this family connection, as shown by the following figure (Figure 2).⁶

Figure 2: Phylogenetic Tree Showing the Relationship of Modern Whales to Living and Extinct Even-Toed Hoofed Mammals
This tree is based on both bony features and DNA data. The organisms presented in blue are semi-aquatic or aquatic forms. Organisms shown in green are terrestrial even-toed hoofed mammals (Artiodactyls). In black is shown a member of the odd-toed hoofed mammals. In red is an extinct fossil ancestor group. (This figure is adapted from Fig 1a in Reference 6).

The blue lines in the diagram show species in which the skeleton is specially thickened, and the bone structure more dense. This is an adaptation which allows wading animals (like modern hippos and the fossil Indohyus) to be good “bottom-walkers” (it prevents them from floating due to lighter body tissues), and allows fully marine organisms (like modern whales) to have “neutral buoyancy” (so they don’t always tend to pop up to the water surface, like a cork). There has also been progress in clarifying the relationships between fossil ancestors of hippos and those of modern whales. A recent study of hippo evolution, based only on skeletal characteristics, has conclusively shown that the hippo family are descended from an extinct group of fossil Artiodactyls, known to go back more than 40 million years, and whose fossils are from southern Asia. Furthermore, this study produced a phylogenetic tree predicting that this extinct hippo ancestor group also shared a common ancestor with the fossil whales.⁷ Thus the investigation of hippo origins is independently leading us back toward the origin of whales. However, in this study the statistical support for predicted common ancestor of the ancient hippo group and the ancient whale group is not as strong as scientists would like to consider this “case closed”. What is necessary is more fossils, of the appropriate age in order to complete the story of hippo evolution. We still need that to fill in the details of the predicted relationship of hippos to modern whales.

Thus the “Whales’ Tale” is not yet complete. It is a story of scientific discovery in progress. As we finish, let’s briefly summarize what we have found out. Different types of DNA evidence agree that modern whales are most closely related to the even-toed hoofed mammals, despite the obvious great changes in limb anatomy of the modern whales. This prediction has been amply confirmed by the fossil record. The DNA sequence evidence predicted a time frame during which critical early events in evolution of whale ancestors should occur. This prediction has also been amply confirmed. Finally, DNA evidence predicts that modern whales are most closely related to hippos. There is some fossil evidence supporting a predicted common ancestor, but more data is needed. A final caution to possible sceptics – this state of “unfinished business” is precisely how the scientific process works. There is no “crisis”. There is no indication that evolution is not true. There is simply the ongoing work of mapping out of various lines of evidence. A scientific conclusion is considered well supported if “all roads lead to Rome”. In the case of whale evolution it might be prudent to say that the evidence has not quite converged in Rome yet, but that we are now in the suburbs. That is precisely what makes science interesting and fun. Stay tuned!

The next blog in this series can be found here.

References:

1: Thewissen J.G.M., Williams E.M., Roe L.J. and Hussain S.T. 2001. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature. 413: 277-281.

2: Gingerich P.D., ul Haq M., Zalmout I.S., Khan I.H., Malkani M.S. 2001. Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan. Science. 293:2239-2242.

3: Coyne, J.A. 2009. Why Evolution is True. Viking Penguin, New York. Pg 50.

4: Numella S., Thewissen J.G.M., Bajpai S.,Hussain T., Kumar K. 2007. Sound Transmission in Archaic and Modern Whales: Anatomical Adaptations for Underwater Hearing. The Anatomical Record. 290:716-733.

5: Thewissen J.G.M., Cooper L.N., Clementz M.T., Bajpai S., Tiwari B.N. 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature. 450:1190-1194.

6: Geisler J.H. and Theodor J.M. 2009. Hippopotamus and whale phylogeny. Nature. 458:E1-E4.

7: Boisserie J.-R., Lihoreau F., Brunet M. 2005. The position of Hippopotamidae within Cetartiodactyla. Proceedings of the National Academy of Sciences U.S.A. 102(5):1537-1541.

It is reasonably well known among evangelical Christians that all living humans trace their mitochondrial DNA back to a single woman (a so-called “mitochondrial Eve”) and that all living males similarly trace their Y-chromosome DNA back to a single male (a so-called “Y-chromosome Adam”). These individuals are commonly assumed by evangelicals to be the Biblical Adam and Eve, the first humans alive and the progenitors of the entire human race. While most young-earth and old-earth creationist organizations make this claim, perhaps one of the best-known organizations to do so is the old-earth creationist / anti-evolution organization Reasons to Believe, who have produced numerous articles, podcasts, and even entire books on the subject.

In contrast to this common evangelical understanding, the scientific picture is rather different. Mitochondrial Eve, though the most recent common matrilineal ancestor of all humans, was but one of a large population living about 180,000 years ago. So too for Y-chromosome Adam: he was also a member of a large population, and he lived about 50,000 years ago. As has been discussed several times here at BioLogos, there are multiple lines of evidence that indicate the human population has never been below around 10,000 members at any time in its history: we branched off as a large population to form our own species.

When presented with the evidence for human population sizes over our evolutionary history, a common point of confusion for evangelicals is how this evidence fits with Mitochondrial Eve. How can we all come from one woman (and one man) but also come from a large population of 10,000 individuals? Aren’t these two observations in conflict?

The answer is no, these lines of evidence fit together. Humans do come from a large population, and all present-day humans do inherit mitochondrial and Y-chromosome DNA from specific individuals in the past. The reason for the apparent discrepancy lies in how mitochondrial and Y-chromosome DNA are inherited, as we shall see below.

Mitochondria are organelles responsible for energy conversion, and they contain their own small, circular chromosome that they replicate apart from regular chromosomes in the cell nucleus. Mitochondria are not passed on to progeny through sperm, but only through the egg: as such, mitochondrial DNA is passed on solely through the maternal line. Consider a small pedigree (family tree) below. Circles represent females, males are represented with squares. In this family, one grandmother (the woman at the top right of the pedigree) has passed on her mitochondrial DNA to her sons and daughter, but only her daughter passes it on to the next generation. All individuals who have this grandmother’s mitochondrial DNA are shown in blue:

Conversely, if we examine Y-chromosome inheritance in this same family, we would see that (obviously) women cannot pass it on to their children. Here, the red lines show all males who have descended from a grandfather of the family (the male at the top left of the pedigree):

Now we are ready to examine how these types of DNA are inherited in a larger group, and compare their modes of inheritance with regular chromosomal DNA. While it is not possible to draw out a pedigree for a population of 10,000 individuals, let’s examine a smaller group to see how a specific mitochondrial sequence can “take over” a population of organisms (note that this effect applies to other organisms besides humans that use an XX – XY system of sex chromosomes).

In the family tree below, three mitochondrial DNA variants are present in the first generation (the top row of the pedigree) and a represented with different colors (green, blue and red). Tracing the inheritance of these mitochondrial DNA versions through the family tree shows that all living members of this population (the bottom two rows) have inherited the red version only. The blue and green versions eventually hit a dead end where they were not passed on (either through females who did not have children, or males). As such, all living individuals can trace their mitochondrial DNA back to this group’s “mitochondrial Eve”, the woman at the top right of the tree with the “Mito 3” variant.

Let’s now examine Y-chromosome inheritance patterns in the exact same family tree. Suppose there are three Y chromosome variants present in the first generations:

Here we can see that the current population has inherited its Y-chromosome DNA from one individual as well (variant 1, the red lines) and that the other Y-chromosome variants (blue and green) hit dead ends through males that did not reproduce or men who only had daughters. All living members of the population trace their Y chromosome DNA back to an individual (filled in with yellow) who lived two generations after their most recent matrilineal common ancestor (the woman at the top right).

Now we are ready to examine regular chromosomal inheritance in this same family tree. Genetic variation on chromosomes other than the Y can be passed through either gender without problem, and individuals can have two variants at a time (one on the chromosome inherited from mom, the other on the chromosome inherited from dad). These key differences (compared to how mitochondrial DNA and Y chromosomes are inherited) produce a very different effect. In this same family, numerous variants (represented by the different colors) have been transmitted to the present generation without loss:

Notice the middle couple in the first generation in the pedigree. This man’s Y chromosome did not make it to the present day, and similarly his wife’s mitochondrial DNA did not make it either (scroll up to see this if you need to refresh your memory). So, they contributed nothing to the current generation, right? Not at all: both of them have passed on regular chromosomal variation to the present day (traced as blue and black lines).

In other words, it would be incorrect to examine this population, determine (correctly) that they share common mitochondrial DNA and Y-chromosome ancestors, and then go on to conclude that these two individuals were an ancestral pair that started this entire family. We know that this group descends from a larger population, because genetic variation in the present population is too large to explain as coming from one pair (there are five colors, or genetic variants in this population, and the max any one pair could carry is four, with two each).

While this example examines a small family, the same principles apply to larger groups: mitochondrial and Y-chromosome lineages, though interesting, cannot be used to estimate population sizes over time. For that type of work, regular chromosomal variation should be examined. Present day human genetic variation indicates that though we all share a common mitochondrial DNA and Y-chromosome source, these individuals came from a population of at least 10,000 individuals, and that they lived over 100,000 years apart. If you are interested in examining the evidence for human population sizes, Darrel Falk and I have discussed it previously.

In summary, anti-evolutionary groups, such as Reasons to Believe, that claim that the evidence for Mitochondrial Eve and Y-chromosome Adam supports an ancestral couple for the entire human race are not interpreting the data correctly. They have failed to account for the unique pattern of inheritance these types of DNA have in populations.

Photo courtesy of Lewis Schofield.

Introduction

Today BioLogos begins a series that we think ought to have significant impact on evangelical churches far beyond the local congregation in Arlington, Massachusetts where it was first delivered. A recent editorial in Christianity Today stated that many Christians likely face another "Galileo moment." In that earlier era, finding that the earth moved around the sun--and not the other way around--caused the Church to reorient its understanding of certain scriptural passages. Today, interconnecting strands of evidence all of which lie at the heart of biology, geology, physics and astronomy require segments of the Church to carefully evaluate its magnificent creation narrative--it needs to be certain it is hearing God's message in the way that God intends for it to be understood. It is healthy for the conservative wing of Christianity to be carefully examining the genre of the creation narrative. It has had to do this once before and, it is appropriate to prayerfully seek clarity once again. Christians are truth-seekers and God's Spirit will guide the process as we sincerely seek that wisdom which is from above.

Oratory, at its best, has long been an important key in opening the door to new and dramatically important insights. Pastor David Swaim of Highrock Church in the Boston suburb of Arlington illustrates this poignantly. In fact his sermon is so significant, we've asked permission to post it in serial form so that each of us can deeply reflect on his words in a protracted fashion. We encourage you to let others who are conflicted over this issue know about the series so that they can follow it. Indeed, we believe It will be a great series for small group discussions--we need to lovingly support each other as we seek God's guidance in coming to understand God's truths.

In this sermon, Swaim discusses our belief in God as creator, or “Maker of heaven and earth”, as the Apostle’s Creeds so poetically states. To begin, he reminds us that some passages in the Bible, like the parable of the prodigal son, convey deep truths even though they are not historical accounts. Asking “the wrong questions”—questions that focus on arbitrary details—about such stories can cause us to miss out on their intended message. In a similar way, he says, it is possible that we might be asking the “wrong questions” about the opening chapters of Genesis. In recent years, conflict has erupted because a literal reading of Genesis seems to contradict the findings of science. Swaim suggests, however, that accepting scientific evidence about things like evolution and the age of the earth need not rule out faith in Scripture.

If you wish to jump ahead and hear the sermon in its entirety, you may do so here.

Introduction written by the BioLogos editorial team.

"Maker of Heaven and Earth" (transcript)

One of my favorite parables is that of the lost son. There’s a lot to it. Basically, it’s a story that Jesus told about a young man who insulted his father by demanding his share of the inheritance early, then ran off to spend that money on wild living, and found himself destitute when the money was gone. In desperation, he returned to his father, asking to work as a servant. But instead of being angry, his father joyfully embraced his lost son and threw a huge feast to celebrate his return. It is a great story that Jesus tells to help us understand God’s amazing grace.

How many of you know this story? Raise your hand, if you would. Okay. Now I want to make sure I’m clear…that’s a lot of you…I don’t mean just like, you know it because I just told it to you. I mean you know it because you’ve heard a sermon on this before, or maybe you’ve read it on your own. Raise your hand high if that’s true of you. Wow, still a lot of you. That’s perfect because I actually have a couple of questions maybe you can help me with. You see, it says that the father saw the son while he was still a long way off. Can anybody tell me how far off was the son at that point? Anybody know that? Because, you know, they didn’t have glasses back then, and the father was really old, so how far could he really see? It just doesn’t really add up for me. Can anybody tell me about that? Nobody? Okay. Well I have another question. Maybe this one’s easier. What town did that family live in? Does anybody know that? No? Nobody? What town they lived in? People, this is one of the greatest stories of all time! This is a story that has changed thousands of lives, including many of yours! How can you say that you know this story, that you understand this story, if you don’t even understand these basic facts? Okay, well maybe this is easier. Speaking of family, the Bible’s into family values, so I want to know—where’s the mother? Can anybody tell me? Is this family not intact? What’s wrong? Did they get a divorce maybe? And how come the father ended up with the custody of the sons? And why did they only have two? Families back then had much bigger families. Maybe they just got divorced too early? But I mean he seems so nice—why do you think she left? Anybody know these things? I mean I just don’t get it. You all tell me you know this story, and yet you don’t understand just these simple things about it.

Obviously, my questions miss the whole point of the story. There was no mother, or for that matter, no father or son either. This never actually happened. It’s just a parable. It’s one of the many marvelous stories that Jesus told in order to help us understand something that was hard to see. Now does that make it so that this story isn’t true? No, it is true. This story communicates some of the most important truths in the universe—about God’s nature, and the way that we relate to him. There are many passages in scripture that promise God’s love, or praise God’s love, or even try to explain God’s love. But this passage helps us grasp that truth in a way that’s much more effectively communicated than just through direct reporting. This way helps us feel it. This event never happened, but it’s one of the truest stories in the world. And what a shame for someone to dismiss it as irrelevant because it’s not literal history, or miss the point by asking the wrong kinds of questions.

Now I bring this up because just like my questions miss the point of the lost son parable, so, I fear, many of us ask the wrong questions about the beginning of the book of Genesis, which we read from just a few minutes ago. Not only does this generate needless confusion and division, it also makes us miss the point, miss the life-changing truths that we could see if we asked the right questions. Right now we’re in a sermon series studying the Apostle’s Creed, an ancient declaration of faith in the God of the Bible. And today, we’re considering the word “creator.” So, Genesis seemed like the right place to go.

Like the story of the lost son, most of you know the basic outline: God created the universe in six days and then napped on the seventh (so those of you who nap through my sermons every Sunday, you’re in good company!). But by adding up all the names of the people mentioned in Genesis, and throughout the rest of the Bible, seventeenth century Bishop Ussher determined that the creation of Adam and Eve, and everything else, happened in 4,004 BC—about 6,000 years ago. And that’s great. But you’re probably also aware that this creates some tension with contemporary scientists who suggest a different timeline. Considering the evidence offered by the size and expansion rate of the universe, plate tectonics, fossil evidence, and genetics, their best guess is that the universe was created by a big bang about 13 billion years ago, the earth appeared about 4.5 billion years ago, and the earliest humans existed about 200,000 years ago. In the past 300 years, this has become a very heated debate. Apparently, we need to choose whether we believe in science or in scripture. At least that’s the claim made by the most strident voices on each side, so the general population seems to have accepted that if you believe in God you can’t believe in evolution, and if you believe in evolution then you can’t believe in God.

This topic arouses passions and anxieties in many people, including some in this room. No matter what your perspective is, I’m probably going to say something today that you’ll disagree with, and might even make you angry. There’ll be plenty of time for you to set me straight in the coming weeks. But for the next half hour, in order to allow the possibility that we might hear something new, or even learn from the Holy Spirit, let’s lay aside our defensiveness so that we can at least consider why we are so attached to whatever ideas we have, and evaluate whether our devotion to one truth may be blinding us to others. As scientists have discovered more and more evidence supporting the basic evolutionary theory outlined in Darwin’s Origin of Species, Christians have responded in a variety of ways.

Science has been right about so many things, so some Christians have embraced evolution and felt forced to abandon their trust, not only in the truth of Scripture, but also in the God it describes. Other Christians, including many renowned scientists, have fought back by pointing out the many flaws in evolutionary theory and proposing alternative theories of their own. These include Young Earth Creation, which asserts that the earth was created in six days six thousand years ago, and offers thoughtful explanations to reconcile the findings of science with the words of Genesis 1. Old Earth Creationists do the same thing, but contend that each of the days in Genesis could represent an epoch, or a million years, or whatever amount of time, instead of just a 24-hour day. This is linguistically legitimate—it’s a fine interpretation of the Hebrew word “day” in Genesis—and it recognizes that it’s hard to measure a day before the invention of the sun in day four, anyway. So, Old Earth Creationism opens up many possibilities to reconcile scientific claims about the age of the earth with a literal interpretation of Genesis. Theistic Evolution takes further steps to accommodate evolution while still honoring God as the one who created heaven and earth and everything in them through the evolutionary process. This is attractive because it eliminates the conflict between science and scripture, but it requires a very different way of reading Genesis. They suggest that, like I did with the parable of the prodigal son earlier, perhaps we’re asking the wrong questions about Genesis so that we’re inventing an unnecessary argument, and even worse, we’re also missing what the first chapters of Genesis really are all about.

In the next installment, to be posted tomorrow, Pastor Swaim goes on to discuss the Genesis passage in detail.

]]> Mon, 17 Oct 11 08:00:03 -0700 David Swaim http://biologos.org/blog/new-limbs-from-old-fins-part-2?utm_source=RSS_Feed&utm_medium=RSS&utm_campaign=RSS_Syndication http://biologos.org/blog/new-limbs-from-old-fins-part-2?utm_source=RSS_Feed&utm_medium=RSS&utm_campaign=RSS_Syndication Critics of evolution sometimes portray the theory as an untestable historical conjecture, depicting it as fundamentally different from experimental science in the lab. But the hunt for the earliest tetrapods was an effort to test a hypothesis that had generated a prediction. In the previous post in this series, we looked at the remarkable blueprint that underlies all limbs – one bone, two bones, blobs, digits – and considered some ways we might explain it. One potential explanation is, roughly speaking, design. Perhaps the blueprint represents an idea or preference in the mind of the Creator. Perhaps the blueprint represents an optimized design, one so superior that there is no better way to build a limb. The other potential explanation is common ancestry. The blueprint was present in ancestors of the distant past, and it has been retained with modification in all tetrapod vertebrates that have descended from those pioneering ancestors. We noted that one explanation need not entirely preclude the other.

In the rest of the series, we will look closely at the evolutionary explanation for the blueprint. That explanation postulates that tetrapod limbs arose during a particular era in life's history, and that they arose as modifications of the fins of fish. And the evolutionary explanation isn't just an interesting idea. It's a comprehensive explanation – it helps us to understand bones, fossils, genes, chemical signaling systems. It provides a coherent framework for understanding why limbs are the way they are, and how they got that way.

Comparing the anatomy of tetrapod vertebrates and fish

The idea that tetrapods arose from fish is not new; E.D. Cope proposed in 1892 that tetrapods descended from lobe-finned fish. (Modern lobe-finned fishes include coelacanths and lungfish, and comprise one of two divisions of the bony fishes. The other division, the ray-finned fishes, includes most familiar kinds of fish.) In the early days, biologists inferred ancestral relationships between species largely through comparative anatomy and embryology: they would carefully classify organisms according to their structure (including their structure during development) and look for relationships that generated nested hierarchies. A simple nested hierarchy goes something like this: 1) animals with backbones; 2) animals with backbones and limbs; and 3) animals with backbones, limbs, and hair. Animals in group 3 also belong to groups 1 and 2, while animals in group 2 also belong to group 1, and so the groups together define a nested hierarchy. Such studies alone could have led some scientists to infer an ancestral relationship between fish and tetrapods, and perhaps those studies did convince them. But then there were fossils of various types of fish and other vertebrates, many long extinct. That fossil record was relatively sketchy in 1892, but it nevertheless led Cope and others to conclude that certain fish had given rise to tetrapods at a particular time in natural history.

The fossil record shows a fish-to-tetrapod transition

Here are some basic findings from the fossil record that suggest a fish-to-tetrapod transition and that have been known for decades:

• Fish, including fish with bones, lived on the earth before tetrapods appeared. Specifically, fossils of bony fish first appear in rocks from about 420 million years ago.

• Tetrapods appear in the fossil record at a particular point in history and then persist and diversify in subsequent eons. Their arrival was long thought to have occurred about 365 million years ago, although some recent findings have challenged that hypothesis.

• Tetrapods that still had some fishy features were prowling the planet 365 million years ago.

• Lobe-finned fish that were starting to look more like tetrapods were eating other fish about 385 million years ago.

Even many decades ago, there were hints that something interesting happened between 400 million years ago and 365 million years ago. Let's take a close look at the ancient animals that suggest the fish-to-tetrapod transition.

Ancient animals

The most primitive known tetrapods for which we have skeletal remains lived 365 million years ago. They were undeniably tetrapods, but there was definitely something fishy about them. (Heh heh.) One of the most famous of these creatures is Acanthostega, discovered in 1987 by British paleontologist Jennifer Clack and pictured below. Acanthostega is a card-carrying tetrapod, with fingers and toes. But it has a fish tail, with fin rays. Another well-known primitive tetrapod is Ichthyostega, which lived around the same time as Acanthostega. Like Acanthostega, it is a true tetrapod, but has several odd fish-like structural features. For example, its skull is more fish-like than that of Acanthostega. In summary, both Acanthostega and Ichthyostega already used the limb blueprint, even though both also had some fish-like anatomical characteristics. Their presence 365 million years ago shows that tetrapods must be at least that old, and their mixture of anatomical features suggests that the transition happened not long before that.

And what about the lobe-finned fish that looked a bit tetrapod-ish? That animal is Panderichthys, described as “vaguely crocodile-shaped” with skeletal features that were tetrapod-like. Specifically, this ancient fish had tetrapod-like “shoulders,” and recent analysis found some finger-like bones at the ends of the fins. The creature also had a breathing hole on the top of its head. These fish lived around 385 million years ago.

The hunt for the earliest tetrapods

Taken together, these observations suggested that the fish-to-tetrapod transition occurred between 385 and 365 million years ago. Eager to see what that transition looked like, scientists began to look for 375 million-year-old rocks in which they might find animals at the beginning of tetrapod-hood. They wanted to catch evolution in the act.

Let's stop and think about this, because it's cool and because it's important to note the extent to which evolutionary biology is hypothesis-driven. Critics of evolution sometimes portray the theory as an untestable historical conjecture, depicting it as fundamentally different from experimental science in the lab. But the hunt for the earliest tetrapods was an effort to test a hypothesis that had generated a prediction. Based on the hypothesis that lobe-finned fish were ancestors of tetrapods, scientists predicted that intermediate animals, “fishapods,” would be found in the gap between Panderichthys and Acanthostega. To evaluate the prediction, all they needed to do was find some suitable 375 million-year-old rocks.

Neil Shubin describes that search in the first chapter of Your Inner Fish. He and his colleagues found suitable rocks in the islands of the Arctic: the right age, nicely exposed (by erosion), and representative of the kind of environment that their quarry would frequent – freshwater streams. They made their biggest discovery on their last trip (“a do-or-die situation”) in 2004. That discovery was Tiktaalik roseae, the “fishapod.”

The “fishapod”

Tiktaalik roseae is one of the most extraordinary fossil intermediates ever described, and its public debut in 2006 was front-page news. An artist's conception of the animal is pictured below.

There are several aspects of the anatomy of Tiktaalik that earn it the title “fishapod.” Like a good fish, it had scales and webbed fins. Like a tetrapod (more specifically, like a crocodile), it had a flat head, with eyes on the top of the head, and it had a neck. But what about those fins? Or are they limbs? Remarkably, the answer seems to be, “both.”

The fins of Tiktaalik were part fish fin, part tetrapod limb. On the outside, they looked like fins, with webbing. On the inside, though, these fins were clearly tetrapod-like. Amazingly, the fins of Tiktaalik were built using a primitive version of the limb blueprint: one bone, two bones, blobs, digits. As Shubin writes in Your Inner Fish, “We had a fish with a wrist.” (The Tiktaalik roseae web site at the University of Chicago is a great source for images and more information.)

Let's address three questions about Tiktaalik that might have occurred to you. First, why might animals like Tiktaalik have developed tetrapod-like fins? Shubin and his colleagues suggest that these limb-like fins may have been useful for doing “push-ups” in the shallow water. (Like Panderichthys, Tiktaalik had a breathing hole on top of its head and was clearly adapted for living and moving in shallow water.) Second, is Tiktaalik an ancestor of all tetrapods? No, not necessarily. What Tiktaalik shows us is that animals were developing tetrapod features in the context of fish bodies, and Tiktaalik shows us the context (shallow water) in which this likely occurred. But that doesn't mean that our lineage arose from Tiktaalik itself. Finally, is Tiktaalik now the oldest tetrapod? No, apparently not. For one thing, Tiktaalik is truly transitional, and probably therefore not worthy of full tetrapod membership. But more notably, data published in 2010 show that tetrapods are a lot older than was thought at the time of Tiktaalik's discovery. The new findings show footprints that are unmistakably those of a tetrapod, in rocks about 395 million years old. Surprisingly, then, tetrapods were already on their way long before Neil Shubin's specimen lived. Tiktaalik is truly a fish/tetrapod intermediate, which was living at the same time as animals that were fully tetrapods. A simple story of succession, in which intermediates disappear and are replaced by less intermediate types, seems to be an oversimplification.

In conclusion, the fossil record provides evidence that the fins of fish and the limbs of tetrapods are related by ancestry: limbs seem to be modified versions of fins. What other evidence supports this proposal? In the next post, we will turn to developmental biology, and explore the meaning of the term 'homology.'

Further reading:

Neil Shubin (2009) Your Inner Fish: A Journey Into the 3.5-Billion-Year History of the Human Body. New York: Vintage Books.

Carl Zimmer (2006) A Fin is a Limb is a Wing: How Evolution Fashioned its Masterworks. Online at NationalGeographic.com.

Tiktaalik roseae website at the University of Chicago.

Jennifer Clack's website at the University of Cambridge.

Images are from Wikipedia.

Early years

I grew up in northern British Columbia, Canada, in a small town called Terrace, where I spent a lot of time in the woods with my father and brother hunting and fishing. Little did I know how spoiled we were –Terrace and its environs are a world-class destination for outdoor pursuits, especially fishing. As a hunter, my father was always interested in patterns in nature: what animals fed on, where they moved at certain times, and so on. Even as a child I can remember being similarly interested in how nature worked. Often, while dad fished, I was the one brandishing a net, bucket at the ready, to see what critters I could scoop up and examine. While my peers at school wanted to be astronauts and firemen, I dreamed of being a scientist some day.

My local church setting was pretty much a wash when it came to science. Science was not held up as a potential vocation, but neither was it denigrated as suspect. Creation science did not seem to be a priority, but rather global missions. As such, science–faith issues were seldom, if ever, discussed in the church I grew up in. I can vaguely recall one dust-up over eschatology, which was perhaps the first time I realized that not all Christians agree on everything when it comes to interpreting the Bible. I cannot, however, recall any similar discussion about the means by which God created.

High school

Despite evolution being almost a complete non-issue in my local church, I seemed to acquire a generic, evangelical, anti-evolutionary position by default. Certainly I knew of no Christians who accepted it, and I can still recall the feeling of dread I would get even at hearing the word evolution spoken aloud. That word, in my mind, was effectively synonymous with atheism. Fortunately, even in high school biology class evolution seemed to be a complete non-issue too, for as far as I can recall evolution was not a subject I was exposed to in high school. In fact, in high school I found biology to be intensely boring – it seemed to me to be mere regurgitation of information. Chemistry and physics seemed much more interesting, and I suspect now the reason for the appeal they held for me then was that they were taught from their underlying principles: atomic theory, Newtonian mechanics and Einstein’s theories of special and general relativity. What was missing was the theoretical underpinnings of biology: a way to organize the laundry list of information into a context. It would be a long time before I realized that evolution was the theoretical underpinning that was missing from my biology experience. Given my dread of the topic, had this been pressed on me in high school I may have never pursued a career in biology.

As a high school student I had left behind my childhood desire to be a scientist. After all, I knew no scientists, and had no notion of how one might become one. In my small-town, northern Canadian setting, a medical doctor was about as close as one came to a scientific career that I was aware of. Accordingly, I set my sights on medicine, and off I went to the University of British Columbia in the fall of 1992. Biology seemed a natural choice for an aspiring doctor, so that was what I chose.

One church incident that I do recall with great clarity happened just before I left for university. There were several recent grads in the congregation: some were headed to Bible College, and others, such as myself, were off to “secular” universities. Our congregation had a time of prayer for all of us, but the contrast was stark: prayers of thanksgiving and blessing for those bible-school bound, but for those of us heading into the lion’s den, prayers of supplication that we not lose our faith in the process. I can remember steeling myself for the upcoming battle, where professors tried to snare me with their atheistic teachings and peers likewise pressured me to give up my faith. One battle I knew was coming was the evolution one: certainly, as a biology student, this would be one of the challenges I would have to face.

University 101

To my delight, I found that university was not going to require me to hold my breath spiritually for four years. Soon I was involved with Inter-Varsity Christian Fellowship and enjoying the friendship of many other Christian students. Biology, however, remained boring and laundry-list like. My grades in chemistry and physics were still higher than those within my declared major of biology. The one bright spot was that evolution barely seemed to rate a mention except in passing. Certainly no compelling evidence for evolution was ever mentioned – professors seemed too intent on teaching the details of their fields to provide a wider evolutionary context. Even the introductory survey courses seemed more intent on a mere description of biodiversity rather than any detailed understanding of how that diversity arose. I did note that there was a 400-level evolution course, but thankfully it was an optional elective. Avoiding the evolution issue was easier than I had thought: I simply skipped taking that elective.

At the start of my third year, with my grades still marginal for medical school, I somehow decided to upgrade into a biology “honors” student. This meant two things: working on an undergraduate research thesis with a faculty member, and attending an “honors seminar” class with other students in the same program.

Experiencing my first taste of research was electrifying: here at last was genuine science! Not long after, my upper-level classes seemed a lot more interesting and relevant, and also much easier. My grades improved dramatically, and medical school looked to be a live option once more – except for the fact that my childhood interest in science had blossomed again.

Standing against evolution

The undergraduate thesis seminar class included an assignment that required students to familiarize themselves with the research of one of the professors in the department. As the list of potential faculty and their research interests was read, one caught my attention: the work of Dolph Schluter on experimental evolution. I decided to take the opportunity to score a few hits on the so-called “theory” by signing up for this topic. What followed can only be described now as a painful memory: full of ignorance and confidence, I trotted out every long-refuted, anti-evolutionary argument in the book (in fact, if memory serves, my “research” was nothing beyond skimming one anti-evolutionary book for its arguments). I remember that the class was quite engaged by the presentation, and there was some vigorous back-and-forth with some of the students who knew the science better than I because of their research work. I can only imagine what the thesis class faculty supervisor was thinking at the time. The worst part was that Dolph himself arrived early for his own presentation to the class, which was to follow my own. As such, he was able to hear a good portion of my nonsense.

Fortunately for me, Dolph had no interest in what would have been a very easy dressing-down. Rather, he restrained himself to a few words to the rest of the class on their lack of knowledge. Personally, I thought I had scored a victory for the faith, against the evils of evolution.

In the next post in this series, I’ll describe my introduction to, and enthusiastic embrace of, the Intelligent Design Movement.

Media-hungry atheist, creationist and religious fundamentalist provocateurs have successfully dominated the science and religion narrative for the past decade or so. In doing so, they have created the false impression of an ongoing unavoidable war between the two camps. A recently published large-scale survey of college students, however, finds that the call to arms has fallen on deaf ears. For the vast majority of American university students, there simply is no conflict between science and religion.

Christopher Scheitle, a Penn State sociologist, analyzed survey data from more than 10,000 students at over 200 colleges and universities across America (Journal for the Scientific Study of Religion 50, p. 175). The students were surveyed both as freshman and juniors so that attitudinal change over the course of their university years could be assessed. Among the many items on the survey was one that asked the following: "For me, the relationship between science and religion is one of..." Four possible responses were provided: (1) Conflict -- I consider myself to be on the side of science, (2) Conflict -- I consider myself to be on the side of religion, (3) Independence - science and religion refer to different aspects of reality and (4) Collaboration -- each can be used to support the other. Students were also asked about their religious beliefs and affiliations and their course of study (i.e. major).

Results showed that nearly 70 percent of college freshman saw the science/religion relationship as one of either independence or collaboration. The minority who saw science and religion in conflict were roughly evenly split between those who sided with religion (17 percent) and those who sided with science (14 percent). Even more interesting was the fact that when students changed their opinion over time, the most likely change was moving from a conflict position to one of non-conflict (either independence or collaboration). For example, 70 percent of those who as freshmen said they were on "religion's side" had changed to a non-conflict position by the time they were juniors. Similarly, 46 percent of freshmen who said they were on "science's side" had adopted a non-conflict position by the time they were juniors. By contrast, only 13 percent of freshman who took a non-conflict position changed to one of conflict by their junior year (5 percent to religion's side, 8 percent to the side of science). For most students, more education means less science/religion conflict, not more.

The above results also reflect the fact that the pro-science point of view appears to be more entrenched than the pro-religion point of view. In other words, once someone has adopted "science's side" in a perceived science and religion conflict, it is harder to move them from this position compared to when someone has adopted "religion's side." Exactly how to interpret this is unclear. Are religious people actually less dogmatic on the issue? Maybe. Maybe the evidence more clearly confirms the rightness of the "science" side and this is why fewer people switch. Then again, if the evidence so clearly supports the "science side" then why don't the majority of people see a conflict to begin with, and why do nearly half of the pro-science folks defect over time?

The apparent greater willingness of "religion side" students to re-examine their stance can also be seen in another interesting finding. Students at religious schools were actually less likely to claim to be on "religion's side" than students at secular schools. This pattern held true even after the results were adjusted for the students' degree of religious commitment and religious conservatism. The author suggests that students at religious schools may feel less threatened than equally religious students at a secular school and that the conflict narrative may be more salient at secular schools.

The breakdown of findings by major also showed some interesting trends. Business and education students were most likely to adopt a conflict approach, with nearly 40 percent doing so, most of whom claimed a pro-religion stance. The conflict approach was endorsed by just under 30 percent of natural science, math and engineering, social science, and arts and humanities students. However, while the majority of "conflict" students in natural science, math and engineering sided with science, the majority of arts, humanitie, and social science students sided with religion. While it is important to keep in mind that most students of all majors saw no conflict, this pattern across majors was somewhat troubling to the author:

"The finding that scientists and engineers are among the most likely to have a pro-science conflict perspective could mean that some of the most influential voices in these public debates might be more likely to fuel the debates than attenuate them. Similarly, future educators are among the most likely to hold a pro-religion conflict perspective. Given that classrooms and school boards have been one of the central forums for the struggle over religion and science, this does not bode well for a reduction of those struggles" (p. 185).

A shrill alarm cry naturally attracts attention and the few extreme voices promoting a science and religion conflict have taken full advantage of this. Seeking common ground or respecting distinct domains are not sexy, but this is where the majority of educated people are when it comes to science and religion. As the author of this survey points out, the non-conflict position firmly established among college students is only a reflection of what has already been found for most working scientists.

The majority position is not always the right one. It is not always the wrong one either. But one is justified in being wary of those who promote conflict (whether in science and religion or in politics, society, etc.) when: (a) it not obvious to most people why the conflict is necessary and (b) those promoting it have something to gain by doing so. Crass opportunism could be afoot just as easily as sincere disagreement.