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.

What does it mean for humanity to be created “from the dust of the ground?”

In many ancient Mesopotamian creation stories, human beings were depicted as deriving from some physical part of the gods. Often this was the result of conflict: humans arose from the blood, flesh or tears of gods slain by other gods. Humans created in this fashion were supposed to serve the gods by performing menial work that the gods had tired of doing themselves. The lot of humanity, then, was one of violence and servitude.

In the Israelite creation stories reflected in Genesis 1 and 2, however, humans are made from the ordinary material of creation: “dust.” Humans are made of earth-stuff, not god-stuff.

At first glance, it may seem that this lowers the status of the human creature. We might ask the question raised by Eliphaz in the book of Job:

Can a mortal be more righteous than God?
Can even a strong man be more pure than his Maker?
If God places no trust in his servants,
if he charges his angels with error,
how much more those who live in houses of clay,
whose foundations are in the dust, who are crushed more readily than a moth! (Job 4:17-19)

Indeed, our humble origins ought to remind us of the fragility of our lives. As the Psalmist says,

You turn people back to dust, saying, “Return to dust, you mortals.”
A thousand years in your sight
are like a day that has just gone by,
or like a watch in the night.
Yet you sweep people away in the sleep of death—
they are like the new grass of the morning:
In the morning it springs up new,
but by evening it is dry and withered.

The elements of which our bodies are made are ordinary and abundant. Science tells us that approximately ninety-three per cent of the mass in a living human body is comprised of elements first formed through nuclear fusion in the hearts of stars. Through almost unimaginably vast and ancient cycles of stellar formation and supernova explosions, this “stardust” of elements has been spread throughout the universe. It is as though God scattered the stars across space and time to seed the universe for life, including your life and mine. And we are thereby inseparably connected to each other, to the air we breathe, to the ground we tread, to all the creatures that fill the skies and crawl upon the earth and teem in the seas, to the depths of all the heavens. We are not transcendent of creation. We are creatures.

Yet we are creatures into which God breathed the “breath of life.” We are stardust and more than stardust. We are not reducible to our constituent chemicals. A “man” or a “woman” is not just a gooey sack of water, carbon and trace elements. Hydrogen, oxygen and carbon are not aware of their own existence. These elements cannot reason or pray or love or write poems. Conjunctions of these elements cannot carry any persistent identity across time. They do not exercise will or intentionality or agency. They are not “selves.”

Most of the cells in a human body are in constant flux: aging, dividing, dying, being replaced. The surface layer of human skin is renewed completely about every two weeks. An adult’s skeleton is entirely remade over approximately ten year periods. It may be that only the neurons of the cerebral cortex and a few other types of cells persist throughout the lifetime of a human body. And eventually, it all does return to “dust.”

Yet we think of ourselves as persisting over time, as comprising an “identity,” a “self.” Perhaps the cerebral cortex provides the stable biological platform for identity and selfhood, but something new emerges from the chemical-electrical soup, new patterns of organization, a different level of causation. We can even make choices that reshape ourselves, both physically and psychologically. The very wiring of our brains changes when we make conscious choices. Mind is both shaped by matter and supervenes on matter.

Materialists who wish to collapse all of human identity into brain chemistry overstep the bounds of “science.” A fundamental principle of scientific practice is testability: is it possible to demonstrate empirically whether a proposition is false ? As Saint Augustine observed many centuries ago, the fact that I acknowledge I could be “wrong” about something means that I am a “self” who is capable of making real choices about things that are in fact true or false. “Si fallor, sum” Augustine said – if I can doubt, if I can be wrong, then I must exist. One who is a true materialist “all the way down” cannot test his or her materialism. There is no possibility of “being” right or wrong, indeed no possibility of “being” – there is nothing but chemistry.

Spiritualists who wish to degrade matter in favor of the soul or spirit likewise are not expressing a Christian anthropology. Indeed, one of the first heresies that encountered the early Christian church was Gnosticism. A core belief of Gnosticism was that matter, including the human body, was essentially evil. Salvation for the Gnostics involved the soul’s escape from the prison of embodiment and materiality. The Gnostics treated the body either with disdain – engaging in extreme ascetic practices – or with antinomian abandon – engaging in extreme sexual license. Either way, their practices were rooted in the belief that matter and the body were unimportant. It’s easy to see how this view continually creeps into both our popular culture and our Church cultures.

Christian theology asserts that humans are spiritual creatures, a unity of body and spirit or “soul,” integrated, not reducible downwards to mere matter or upwards to mere spirit. Perhaps there is no better way to bring these themes together than with a Psalm — here is Eugene Peterson’s paraphrase of Psalm 139 in The Message:

God, investigate my life; get all the facts firsthand.
I’m an open book to you;
even from a distance, you know what I’m thinking.
You know when I leave and when I get back;
I’m never out of your sight.
You know everything I’m going to say
before I start the first sentence.
I look behind me and you’re there,
then up ahead and you’re there, too—
your reassuring presence, coming and going.
This is too much, too wonderful—
I can’t take it all in!

Is there any place I can go to avoid your Spirit?
to be out of your sight?
If I climb to the sky, you’re there!
If I go underground, you’re there!
If I flew on morning’s wings
to the far western horizon,
You’d find me in a minute—
you’re already there waiting!
Then I said to myself, “Oh, he even sees me in the dark!
At night I’m immersed in the light!”
It’s a fact: darkness isn’t dark to you;
night and day, darkness and light, they’re all the same to you.

Oh yes, you shaped me first inside, then out;
you formed me in my mother’s womb.
I thank you, High God—you’re breathtaking!
Body and soul, I am marvelously made!
I worship in adoration—what a creation!
You know me inside and out,
you know every bone in my body;
You know exactly how I was made, bit by bit,
how I was sculpted from nothing into something.
Like an open book, you watched me grow from conception to birth;
all the stages of my life were spread out before you,
The days of my life all prepared
before I’d even lived one day.

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.

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.

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

The origins of human chromosome 2: a brief review

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

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

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

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

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

Enter the Denisovans

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

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

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

Implications for understanding our “becoming human”

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

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

(Click Image for Full Resolution)

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.

Many posts on this Forum have suggested that the cosmological narrative in Genesis 1 is best read as being primarily about God’s identity and agency, rather than about the physical make-up or material history of the natural world. Similarly, we demonstrate our highest regard for Genesis 2’s account of the creation of Eve—the second fully human being—by looking to its meaning in terms of spiritual and interpersonal relationships, rather than genetic ones. While the specific “how” of our being made into the image of God will probably always remain a mystery, the Bible and creeds are clear on the “why” of our creation: we were made to worship the Lord, and be in relation with Him and each other. That intimate, conscious and deeply symbolic knowledge of our maker and fellow human beings is a profound difference that sets us apart from the other creatures.

I have frequently argued that poets are often the most clear on some of the important issues of our faith, including this one. Today we feature a work by Robert Siegel, who identifies the imagination as the faculty by which we recognize and name those spiritual relationships. As he says, “It's the imagination, hence language and art, that establishes the connections”; it is the imagination that allows us to conceive of and name the links between ourselves and creation, ourselves and each other, ourselves and the Creator God.

Though we often focus on Adam’s naming of the animals, and then even of Eve, Siegel helps us remember that it was in hearing his own name that Adam’s whole humanity came into being: he experienced the richness of being called by God to bear His likeness, but also of being called to by one that was profoundly “like him.” Put another way, we are speakers, but also equally hearers. May we, too, be awakened to ourselves and our image-bearing identity by a still, soft voice saying our name. May we, too, in gratitude and delight, call upon the name of the one, Jesus, who is both our God and our fellow man.

“Adam’s Dream”

by Robert Siegel

The Imagination may be compared to Adam's dream:
he awoke and found it truth. --Keats

He saw the garden spreading past the trees
he'd been warned to avoid (yet keep a special eye on).
He'd learned by scents, transported by the breeze,
myriads of roses and how, by hand, the scion

of one to graft on another--and what was edible:
whole families of legumes, grasses, roots,
melons, peaches, apples, pears. Incredible,
the variety of tastes just from the fruits!

But it wasn't enough. Even the breathing animals
with friendly grunt or sigh, silken warm side,
and large affectionate eye were not able
to speak. When he named them, none replied:

His words fell dead on the air--though he said
them everywhere, walking or running to each place:
to the mountain, which echoed back the sounds he made,
or the still pool, returning his own gaze.

But no one answered him until one night in a dream
he woke and heard a soft voice speak his name.

“Adam’s Dream” first appeared in issue 3 of Stonework, the literary journal of Houghton College. © 2001 Robert Siegel

Robert Siegel is the author of nine books of poetry and fiction, most recently A Pentecost of Finches: New and Selected Poems. He has received prizes and awards from Poetry, Prairie Schooner, The Transatlantic Review, the Ingram Merrill Foundation, and the National Endowment for the Arts, and his poems have appeared in numerous journals and anthologies. His fiction includes Alpha Centauri and the Whalesong trilogy, which received the Golden Archer and Matson awards. With degrees from Wheaton, Johns Hopkins, and Harvard, Siegel has taught at Dartmouth, Princeton, and Goethe University in Frankfurt, and for twenty-three years at the University of Wisconsin-Milwaukee, where he directed the graduate creative writing program and is currently professor emeritus of English. He is married to Ann Hill Siegel, a photographer, and lives on the coast of Maine.