There’s a serious point in my playful invocation of Pilgrim’s Progress. Like many of the most complex human endeavors — parenting, farming, becoming a Christian — the life of a scientist is not just an “occupation,” something that occupies us for a while and might then be followed by something entirely different. Being a scientist is as much about being as doing, as much about a particular way of being formed as a person as it is a set of activities or even skills. Training in science is induction not so much into a particular worldview (though it includes absorbing plenty of the kind of cognitive presuppositions that that word suggests) as it is a kind of posture or stance toward the world, toward one’s work, and toward one’s fellow human beings, both scientists and non-scientists. And the life of a scientist is a journey, one freighted with ultimate concerns and laden with values. It is a journey into a set of virtues, the habits and dispositions that make one a person of a particular kind of character.

When we talk about faith and science, we tend to focus on the cognitive content of both endeavors, the truth claims and worldviews that animate these two crucial dimensions of modern human life. These are important matters, and I don’t at all mean to diminish them. At the same time, there are inevitable limits to what any pastor can do to constructively integrate the knowledge content of science — so vast and rapidly expanding that even scientists cannot pretend to be expert in anything but a tiny portion — with the content of Christian faith. But there is another way to approach faith and science which I believe might well be more within reach of most pastors, and more essential to their job description than being deeply literate in the latest scientific discoveries and theories — and that is simply to attend to, and prayerfully support and encourage, the scientific life itself as a vocation that can reflect the image of God and be a place for working out one’s own salvation.

So here is what I wish our pastors — and fellow Christians — knew about the life of a working scientist.

Delight and Wonder

If there is one personality characteristic of the vast majority of scientists I have met, it is delight. There is something about science that attracts people who are fascinated and thrilled by the world. To be sure, any given scientist is delighted by things that you and I may find odd or indeed incomprehensible — the intricacies of protein folding, the strata of Antarctic ice cores, or the properties of Lebesgue spaces (and no, I have no idea what that last phrase really means). But the specificity of their delights is one of delight’s secrets: like love, delight is always most potent when it is particular. It is certainly possible to find lawyers who are delighted by law (I have one friend who can go on at great length, with enthusiasm, about corporate bankruptcies), dairy farmers who are delighted by cows, or lumberjacks who are delighted by trees — but I dare say your chances are much better that when you meet a scientist you will find that they are delighted with the tiny part of the world they study day to day. (At least when they are not frustrated with it — which we’ll examine below.)

In many scientists, delight is matched by wonder — a sense of astonishment at the beautiful, ingenious complexity to be found in the world. This is not the “wonder” that comes from ignorance — “I wonder how a light bulb really works?” — but a wonder that comes from understanding. Indeed, as we progress further into humanity’s scientific era we have been able to disabuse ourselves of a mistaken early-modern notion: that the more the world became comprehensible, the less it would be wonderful. That turns out not to be true at all — ask a scientist. Wonder grows as understanding grows. Indeed, wonder only grows if understanding grows. If we replace our childhood awe of lightning with an explanation like, “It’s nothing but a transfer of voltage across a highly resistive material” (an example of what G. K. Chesterton wittily called “nothing-buttery”) perhaps the world will seem like a less wonderful place. But those who actually pursue knowledge of lightning — of electromagnetism or cloud formation or weather systems or climate — end up being more in awe of the world than they were as children. This is surely one of the remarkable features of our cosmos: the more we understand about it, the more we are in awe of its beautiful elegance and simplicity, and at the same time its humbling complexity.

To be sure, many if not most scientists do not see this wonderful world in the way that most Christians would hope for. For us, wonder is a stepping-stone to worship — ascribing our awe for the world to a Creator whose worth it reveals. For many scientists, wonder is less a stepping-stone than a substitute for worship. Yet they stop and wonder all the same.

Intellectual humility

I doubt that humility is among the first traits most people think of when they think of scientists. And indeed, some scientists (like some academics and intellectuals generally) exhibit a combination of confidence in their own intellect and limitations in their social skills that makes them seem abrasive if not arrogant. A few have made a public career of intellectual overreaching, not least in matters of science and faith. But in my experience (and certainly, let me stress, in the case of my own wife!) this is much more the exception than the rule. If intellectual humility is essentially a willingness to admit what you do not and cannot know, science cultivates humility like few other pursuits can — because in few other pursuits do you so often find out that you were wrong.

Even though we tell the story of science through its high points — the discoveries and confirmed theories that won Nobel Prizes and launched new eras in technology — the actual practice of science, for nearly every working scientist, involves far more failure than success. This is especially true for experimental science, the kind that requires the most direct interaction with recalcitrant reality. On most days, in most labs, the data do not add up, Matlab has an untraceable bug, the laser is on the fritz, and all the cultures have been contaminated when the undergraduate research assistant sneezed. And while each of these everyday setbacks requires immense amounts of patience and persistence to overcome, they are only the quotidian version of the perplexity that begins early in the study of science. Every scientist, in the process of their training, has had to repeatedly discover that their intuitions about the world are simply wrong, or at least incomplete. Even great scientists have come up against the sheer oddity and unpredictability of the world — Albert Einstein, for example, never fully accepted the uncertainty at the heart of quantum mechanics, something that is now universally accepted by physicists.

This regular confrontation with the limits of one’s own knowledge and skill is not to be taken for granted. The other divisions of the academy, the social sciences and the humanities, deal with matters of such variability and complexity that it is often difficult to say conclusively that anyone, or any theory, is entirely wrong. Marx’s and Freud’s grand theories may not seem nearly as plausible as they once were, but there are thousands of people following their lines of thought without losing the respect of their intellectual peers. But Ptolemaic cosmology or Lamarckian evolution now have, simply, no followers. They have been proved wrong beyond a reasonable doubt (although Lamarck’s ideas, interestingly, turn out to have a grain of truth in a way very different from what he expected). Who is likely to be more intellectually humble — someone who early in her training, and daily in her work, learns that her assumptions have been wrong, or someone who can always argue his way out of any intellectual predicament? It is perhaps no accident that “grade inflation,” in which undergraduates’ grades ratchet ever upwards in a nod to the consumer realities of the modern university, is much less pervasive in the sciences, where you can’t cajole your way into an A. The honest, and humbling, truth is that there is likely more intellectual humility in the average physics laboratory than in the average theology classroom.

For more from the "What I Wish My Pastor Knew" series, visit The Ministry Theorem.

Motivated Belief

As we noted earlier [in this book], scientists are not inclined to subscribe to an a priori [i.e., knowledge that is not dependent on experience or empirical evidence] concept of what is reasonable. They have found the physical world to be too surprising, too resistant to prior expectation, for a simple trust in human powers of rational prevision [i.e., foresight] to be at all persuasive. Instead, the actual character of our encounter with reality has to be allowed to shape our knowledge and thought about the object of our enquiry. Different levels of reality may be expected to have their idiosyncratic characters, and there will not be a single epistemic [knowledge-based] rule for all. A physicist, aware of the counterintuitive natures of the quantum world and of cosmic curved spacetime, is not tempted to make commonsense the sole measure of rational expectation. Because of this, we have seen that the instinctive question for the scientist to ask is not “Is it reasonable?”, as if one knew beforehand the shape that rationality had to take, but “What makes you think that might be the case?” Radical revision of expectation cannot be ruled out, but it will only be accepted if evidence is presented in support of the new point of view that is being proposed. Science trades in motivated belief.

One of the difficulties that face a scientist wanting to speak to his colleagues about the Christian faith is to get across the fact that theology also trades in motivated belief. Many scientists are both wistful and wary in their attitude towards religion. They can see that science’s story is not sufficient by itself to give a satisfying account of the many-layered reality of the world. Those who acknowledge this are open to a search for wider and deeper understanding. Hence the wistful desire for something beyond science. Religion offers such a prospect, but many scientists fear that it does so on unacceptable terms. Their wariness arises from the mistaken idea that religious faith demands that those who embrace it should be willing to believe simply on the basis of submission to some unquestionable authority—the claimed utterances of a divine being, the unchallengeable assertions of a sacred book, the authoritative decrees of a controlling community, whatever it may be—simply declared to be unproblematic deliverances of infallible truth. [This describes the attitude that Polkinghorne likes to call “top-down thinking,” vis-à-vis “bottom-up thinking,” which is mentioned at the end of this excerpt.]

The picture that many scientists have of religious revelation is that it is a collection of non-negotiable propositions, presented to be accepted without further argument or attempt at justification. According to this view, faith is simply a matter of signing on the dotted line without taking too much care about the small print. These scientists fear that religious belief would demand of them an act of intellectual suicide. I believe this to be a quite disastrous misconception. If an uncritical fideism [reliance on faith alone] is what religious belief requires, then I would have the greatest difficulty in being a religious person.

What I am always trying to do in conversation with my not-yet-believing friends is to show them that I have motivations for my religious beliefs, just as I have motivations for scientific beliefs. They may not share my view of the adequacy of these motivations, but at least they should recognize that they are there on offer as matters for rational consideration and assessment. Theology conducted in the context of science must be prepared to be candid about the evidence for its beliefs. This task is one of great importance, since the difficulty of getting a hearing for Christian faith in contemporary society often seems to stem from the fact that many people have never given adequate adult consideration to the possibility of its being true, thinking that they “know” already that there can be no truth in claims so apparently at odds with notions of everyday secular expectation.

While science and religion share a common concern for motivated belief, the character of the motivating evidence is, of course, different in the two cases. [SNIP]  Theology lacks recourse to repeatable experimental confirmation (“Do not put the Lord your God to the test,” Deuteronomy 6:16), as in fact do most other non-scientific explorations of reality. Judgments such as that of the quality of a painting, or the beauty of a piece of music, or the character of a friend, depend upon powers of sympathetic discernment, rather than being open to empirical demonstration. Moreover, I have already said that I believe that no form of human truth-seeking enquiry can attain absolute certainty about its conclusions. The realistic aspiration is that of attaining the best explanation of complex phenomena, a goal to be achieved by searching for an understanding sufficiently comprehensive and well-motivated as to afford the basis for rational commitment.

Michael Polanyi (Source)

Neither science nor religion can entertain the hope of establishing logically coercive proof of the kind that only a fool could deny. No one can avoid some degree of intellectual precariousness, and there is a consequent need for a degree of cautious daring in the quest for truth. Experience and interpretation intertwine in an inescapable circularity. Even science cannot wholly escape this dilemma (theory interprets experiments; experiments confirm or disconfirm theories). We have seen [in another chapter] how considerations of this kind led Michael Polanyi to acknowledge the presence of a tacit dimension in scientific practice, depending on the exercise of skills of judgment, and to speak of science as necessarily being personal knowledge, not absolutely certain but still capable of eliciting justified belief. Recall that he said that he wrote Personal Knowledge to explain how he might commit himself to what he believed (scientifically) to be true, while knowing that it might be false. This stance recognizes what I believe to be the unavoidable epistemic condition of humanity.

When we turn to religious belief, it too cannot lay claim to certainty beyond a peradventure [uncertainty or doubt]—for believers live by faith and not by sight. Yet faith is by no means the irrational acceptance of unquestionable propositions. I believe my religious faith to be well motivated and that is why, for me, Christianity is worthy of acceptance and commitment. Religious people are content to bet their lives that this is so. If theology is to prove persuasive to enquirers in the context of science, it will have to set out the motivations for the assertions that it makes, expressed in as honest and careful a fashion as possible. I believe that the argument will need to have the character of bottom-up thinking, making appeal to specific forms of evidence.

Looking Ahead

In a couple of weeks we will continue exploring Polkinghorne’s approach to “motivated belief,” with further excerpts from this chapter.

References and Credits

Excerpts from John Polkinghorne, Theology in the Context of Science (2009), copyright Yale University Press, are reproduced by permission of Yale University Press. We gratefully acknowledge their cooperation in bringing this material to our readers.

JIMMY LIN: Currently I’m on faculty at Washington University at St. Louis, where I am a research instructor in the pathology department. Also, a year and a half ago, I founded the Rare Genomics Institute (RGI)—a nonprofit that helps find cures for people with rare diseases.

ER: What qualifies as a “rare disease”?

JL: These are diseases like cystic fibrosis and Huntingdon’s disease—diseases that affect less than 200,000 Americans each year. There are over 7000 different rare diseases, and less than 5% of them have any therapy. Altogether, they affect about 25-30 million people.

This creates what we call a “long tail problem”—it’s hard for a top-down research system to create research programs for all 7000 rare diseases. So instead, we are creating a bottom-up platform from which the patients themselves can create research projects and help fund them. We connect patients with physicians and researchers, customize a research program with top medical universities, design the experiment, and then use an online fundraising platform to fund the study through [mostly] friends and family of the patient.

Basically, we create a “foundation in a box.” By partnering with the Rare Genomics Institute, patients and their friends and families who want to study rare diseases don’t have to go through the hoops of creating their own nonprofit or lab—we do that for them. So, instead of creating 7000 different nonprofits, we create a generalized platform from which studies can be conducted.

ER: Who qualifies for care through the Rare Genomics Institute?

JL: Anyone with a rare disease can come to us. The main thing we’re doing right now is diagnosis. When families come to us, they either don’t know the disease that’s affecting them or their child, or they don’t know the gene that’s wrong.

For instance, if a child had a condition that doctors couldn’t identify, his or her parents might come to us for help. What we’d do then is sequence the genes of the mother, father, and child, and compare them to reference genome to determine what mutations each of the parents have. Depending on what the disease is and what the gene causing it is, we can filter out mutations that don’t mean anything using the parents’ genomes—then, after filtering, we can potentially pinpoint the genes that fit the genetic pattern of the disease. This is the first step.

After that, we are building infrastructure to determine the effect of these changes and a way to help. For example, after looking at the literature, we can perhaps design experiments using cells extracted from the patient; this part of the process is different for every disease. Then, if we can determine that there is, for instance, a pathway missing a specific enzyme, we can try using drugs, a bone marrow transplant, or gene therapy to try to put healthy cells into the child… But there’s a variety of diseases, of course, so there’s a variety of different approaches—and we’re just starting to explore these aspects.

ER: How did RGI get started?

JL: It really started when I was in medical school at Johns Hopkins—there was this boy that came to our clinic to be seen. My research was in cancer genome sequencing, and the family had come to our department looking for answers about what was wrong with their son. At that point, the family was almost hopeless—they had gone to so many doctors, run so many tests—I decided I wanted to try to help children like this. That’s when my friends and I decided to start the Rare Genomics Institute.

Currently, there are about 50 researchers associated with the organization, and we are all volunteers. It’s growing much, much faster and been more amazing than we’ve ever imagined—we’re already making an impact. In May of last year, we were able to discover a new disease using the world’s first crowd-sourced, crowd-funded genome. Working with researchers at Yale, we delineated a disease of which our patient was the first identified.

Right now, we’re in the middle of raising funding and hiring staff to make this organization one that is self-sustaining, and to increase its impact even more.

Excerpts from Michael Hickerson Interview

MH: …you call yourself a doxologist. What’s the full term you used in your Jubilee bio?

JL: Medical and scientific doxologist.

MH: How did you decide on that term and what does it mean to you?

JL: I listen to a bunch of teaching by J.I. Packer , who teaches theology at Regent College and is one of the leading thinkers on these things. Interestingly, before any one of his classes, he says “Theology is for doxology,” and then the whole class sings the Doxology together out loud in class. I thought, “Wow, that is so great,” because everybody sometimes learns theology just for intellectual things [instead of for worship].

That’s not just true for theology, it’s for everything: biology is for doxology; chemistry is for doxology. That’s when I started to think, I should consider myself, first and foremost, as a person who praises God in what I do. And then no longer make “Christian” the adjective, right? “Doxologist” is the noun. But then what kind of doxologist am I? So I call myself a medical and scientist doxologist. I would call someone, for example, in the marketplace, a business doxologist. Or, someone who does art, an artistic doxologist. To really have the noun as our identity, and then our vocation as just a descriptor of how we do that.

MH: That’s a great point. A noun is always stronger than the adjective. So, you want that to be the focus, rather than the add-on.

JL: In our current culture, we’re defined by our jobs. It’s having a vocation. I wanted to shift away from that. I didn’t want to be a doctor first and foremost, or a scientist, but one who praises God. And evidently, within science you don’t want to call yourself a Christian Scientist. That’s another religion, so . . .

MH: [laughs] That’s right. I run into that, as well, when I’m teaching or talking about science to Christians. You always run into that stumbling block.

JL: With “scientific doxologist,” people don’t confuse them. You do have to explain what it means. And that gets in a little story actually, on what it means about vocation. It’s a small lesson — a teaching point when you do talk to people about vocation and calling. That’s why I use it.

MH: I guess my final question would be what spiritual practices help sustain you? What helps you stay in contact with God and keep a good foundation?

JL: First, I am interested in many, many different things. I sort of mix it up in terms of spiritual practices. Besides the fundamentals, of course, of quiet time, devotional reading, and scriptural reading, I do theological study because I have to do that academically. I find a lot of time with God through the spiritual disciplines, such as times of solitude — which is very interesting for someone who is in academics to no longer think about ideas but just to be quiet before God — how silence, time to think by yourself, or sitting in silence is also something you should foster.

In terms of spiritual formation, what you really need is definitely a good community of people. I have a very supportive community at my church. I’m the deacon of devotions, so that of course keeps me on track. It encourages me as I, in my own spiritual walk, encourage other people. Fundamentally, I think for all Christians, whether you are academic or no matter your vocation or calling, being in the Word and prayer are the most important things. Doing that and being spiritually fed is what is important.

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

The curious case of the missing mammals

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

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

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

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

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

Island endemics and their continental “allied species”

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

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

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

Rethinking independent creation

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

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

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

ECF History

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

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

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

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

The Grantees

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Werner Heisenberg, in a letter to Albert Einstein¹

For many people, science invites awe and religion invites insight. When awe and insight engage, science-and-religion happens.

Ron Cole-Turner²

If we can understand the experiences of the people who work every day in the lab, our dialogues concerning science and religion will be far more fruitful than they would be otherwise. I realised this when someone recently asked me what the highlights had been during my own time as a biologist. I explained that what I appreciated most was the privilege of experiencing science first-hand. My horizons have been expanded, and I now have a better understanding of how vast and complex the natural world is. Appreciating the grandeur of the universe seems to be a universal for humankind, including research scientists in their own peculiar way. Everyone has something to add to a conversation about experiences of awe, as I discovered when I blogged on it recently and invited a number of friends and former colleagues to comment. This sense of awe is a perfect starting point for discussions of science and theology.

Life in the Laboratory

I had always loved finding out how things work, and that was one of the reasons why I chose biology, but actually working ‘at the coal face’ was an eye opener. Living organisms are extremely complicated, so one has to choose only a tiny part of an organism to study: maybe a single gene or a feature of its behaviour. It can take years to understand just one aspect of that tiny part in enough depth to be able to publish an academic paper about it. Experienced scientists describe how the sum of human knowledge is so small as to be insignificant in comparison to what is out there, and I can now appreciate that a little bit. I can also appreciate what fun it is to survey all that un-knowledge, grab a bit of it and try to figure it out.

In the world outside of the lab we hear the headlines about new discoveries, but we have no idea what is behind that one-liner. In reality the story of a discovery in biology may well have started with a graduate student who nervously began their new project, a more experienced scientist who sacrificed precious time to train and supervise them, and the lab head who looked over the data every now and then. There would have been long days and nights in the lab and many false turns before the first piece of promising data emerged. No doubt there were anxious re-runs of experiments to confirm the results, and moments of elation as things started to make sense. The work would have been presented to critical colleagues who suggested further experiments. Frustrating months would have been spent generating the final pieces of data, weeks bent over a computer writing a dense and meticulously referenced paper, submission to a journal, the referees’ criticisms, a few more experiments, resubmission, and a long wait. Finally the paper was accepted and the whole research group joined in the celebration. And this is only the simplest possible version of events – the process of producing successful research can involve large numbers of people over several years, international collaborations, promising leads that go stale, and surprising results from unexpected places.

The ‘real world’ of science is a million miles away from the debates on science and religion that happen in churches, universities and schools throughout the world. Behind every piece of research is a team of people representing different faiths and belief systems, a variety of cultures, social backgrounds and personality types. Perhaps scientists are all a little crazy (who would put in the hours otherwise?), but they’re definitely all motivated in different ways.

The factors that attract people to science are many, though inspiring and supportive parents or teachers can play a large part. The reasons why individuals decide to stick with research, despite all the demands and uncertainties that a life in science brings, are interesting and at times surprising. There is the fascination of understanding the natural world, the value of original research, the prospect of new technologies further down the line, and the privilege of making new discoveries. There is also the opportunity to ask new questions, and the immense satisfaction when things come together and begin to make sense. So far, so predictable. More unexpected drivers are the enjoyable process of tinkering with experimental systems, the opportunity to exercise great creativity, the beauty of scientific data, and a feeling of immense awe when one gets a rare insight into the way the world operates. The rewards for doing science range from the utilitarian to the downright spiritual.

Awe in Science

Awe is an important part of the experience of science – one could almost say it’s a universal. When a scientist feels awe it is usually in response to something complex, precise, ordered, powerful or beautiful. There is an element of unexpectedness and delight, maybe even respect, fear or reverence. Awe always involves the need for some sort of mental adjustment or accommodation: we need to make room in our internal map of the world for this new and amazing experience. The physicist Werner Heisenberg vividly described this process of taking on board a startling new concept when he wrote of his discovery of atomic energy levels:

“In the first moment I was deeply frightened. I had the feeling that, through the surface of atomic phenomena, I was looking at a deeply lying bottom of remarkable internal beauty. I felt almost giddy at the thought that I had now to probe this wealth of mathematical structures that nature down there had spread before me.”

Moments of awe are the rare high-points in science, both rationally and emotionally. Finally something is understood. That understanding and the new possibilities it opens up are wonderful, and the story is told and retold. Scientists, as you might expect, respond scientifically, with new questions and investigations. But they also respond in other ways depending on their personalities: aesthetically, using visual representations of the data in different ways; philosophically, as they discuss the ethical implications of the research or the surprising intelligibility of the universe; or spiritually, as they try to make sense of those feelings of awe and wonder at the immensity and beauty of the world.

When Elaine Howard Ecklund carried out some research into the beliefs of scientists in elite US universities, she discovered a surprising fact: 20% of the people that she and her research team spoke to were not members of any religious group, but considered themselves spiritual. For some of these scientists the experience of beauty, awe and wonder in their work led them to believe that there is something beyond science – one could perhaps call it ‘transcendent’ – an experience that motivated some of them in their research, their teaching, and their lives outside of the lab. I remember having a conversation with a colleague who had experienced something along these lines, so I’m not surprised to hear that many others feel the same.

According to the scientist-theologian Alister McGrath, experiences of the transcendent might involve a sense of the ‘numinous’ – a feeling that something ‘other’ might be behind what one is seeing. Or perhaps someone might encounter a deep truth about the unity of reality that strikes them in a particular way. Perhaps more common would be a moment of unexpected clarity – what some might call an epiphany – where suddenly things make sense. Experiences that might be called ‘transcendent’ are rare, but they leave a lasting impression.

The language used by many scientists when they describe the process of discovery is of a reality that was always there. Perhaps it’s not surprising that scientists are ‘realists’; they think that there is a real world outside of ourselves that waits to be discovered. Science does not answer the ultimate questions about the universe, but scientists are human beings so we just ask those questions anyway – sometimes looking for answers in unexpected places.

Spirituality in Science

At the beginning of this piece I mentioned my growing realisation of the size of the scientist’s task. The seeming inexhaustibility of the created order can be overwhelming, but many see this as something positive. There is so much more to explore. As the Jesuit philosopher Enrico Cantore has said, the mystery of the universe lies not in ignorance, but in dazzling intelligibility. Where do these thoughts of transcendence, reality and mystery lead? For Einstein, they were a religion. A Mind other than our own was somehow responsible for this world that we can make sense of using the language of mathematics. For others, the reality we see in the world leads to ideals that transcend differences of language, culture and religion.

We search for meaning, and we long for more. CS Lewis famously describes the world we live in as a pale reflection of the one to come.³ For those who already believe in God, what we see in science makes sense. We live in a world that operates according to principles that we can understand and describe mathematically. We can utilize what we find for good or evil (and everything in between), and what we discover is both beautiful and awe-inspiring. William Whewell, the nineteenth-century polymath and Master of Trinity College, Cambridge, said that ‘We must find the right thread on which to string the pearls of our observations, so that they disclose their true pattern.’

For me, what we see in science is not evidence for God, but works well as a thought experiment. What would you expect if God existed? In the context of faith, science increases my sense of awe and wonder and helps me to worship God in a more genuine way. The Christian songwriter Matt Redman said that we sometimes ‘take the extraordinary revelation of God and somehow manage to make Him sound completely ordinary’. Science has the power to expand our horizons and helps us to see how great God is. The dazzling intelligibility of the world increases our humility, as we realise that because we ourselves are a fragile and finite part of the universe, we will never be able to fully grasp what we see in an objective intellectual way.⁴ Our response to what we see in the world is rational, emotional and active: worship as well as systematic theology.

The highest mountain peaks and the deepest canyon depths are just tiny echoes of His proclaimed greatness. And the brightest stars above, only the faintest emblems of the full measure of His glory.⁵

Notes

The main sources for this piece are Enrico Cantore, Scientific Man: The Humanistic Significance of Science (New York: ISH Publications, 1977); Olaf Pedersen, “Christian belief and the fascination of science” in Physics, Philosophy and Theology: A Common Quest for Understanding, Eds. Robert John Russell, William R. Stoeger & George V. Coyne. (Vatican City State: Vatican Observatory, 1988), 125-140.; Alister McGrath, The Open Secret (Oxford: Blackwell, 2008).

1. From Enrico Cantore, Scientific Man: The Humanistic Significance of Science (New York: ISH Publications, 1977)

2. Ron Cole-Turner, ‘What Do You Find Most Interesting or Surprising About the S&R Discussion Today?’, Science & Religion Today, 21st May 2012, http://www.scienceandreligiontoday.com/2012/05/21/what-do-you-find-most-interesting-or-surprising-about-the-sr-discussion-today-ron-cole-turner-answers/

3. In C.S. Lewis, The Weight of Glory. SPCK, 1942

4. Jame Schaefer, Theological Foundations for Environmental Ethics: Reconstructing Patristic and Medieval Concepts (Washington, DC: Georgetown University Press, 2009), Chapter 1.

5. Matt Redman, Facedown (Eastbourne: Survivor, 2004).

The first video, “10 Questions with Katherine Hayhoe”, introduces the scientist in a brief and lighthearted interview. Hayhoe is presented with 10 questions concerning her personal life and beliefs. When asked, she explains that one thing people should know about Christianity is that having a relationship with the God of the universe is one of the most incredible experiences that a person can have. As the video unfolds, the viewer quickly begins to realize that, despite her unique profession of two seemingly incompatible beliefs, Hayhoe is a remarkably sane and “normal” individual. Her role model, she explains, is her father-- the person who first introduced her to science and showed her that it could be “really cool”. On a more serious note, the scientist admits that being both a scientist and a Christian can be difficult. The most frustrating thing about her position, she says, is the amount of disinformation which is targeted at her very own Christian community.

In the second video, “Climate Change Evangelist”, Katharine Hayhoe delves into deeper discussion of the perceived conflict between climate change and Christian faith. She explains that admitting her identity as a Christian scientist can be uncomfortable. Since evangelicals are the targets of much disinformation concerning science in general -- and specifically the science surrounding climate change -- many people in the church have a misguided view of the subject and do not look kindly at her career choice. One woman encountered by Hayhoe at a church in Texas, for example, believed that global warming was a lie taught in schools to mislead her children. In an effort to realign misguided views like these, Katharine Hayhoe and her husband wrote a book addressing the deep-rooted emotions often associated with climate change. People fear that addressing the climate issue will bring forth changes in the economy and uproot their way of life. However, Hayhoe encourages her viewers to act out of love, as the Bible calls us to do, rather than out of fear. Acting out of love inspires us to consider the poor and disadvantaged people around the globe when we respond to the reality of a changing climate.

In the final segment of this three part video montage, Hayhoe addresses the question of what climate change means. Specifically, she is concerned about how global warming affects people on a personal level. While global warming generally brings to mind melting ice caps and polar bears, its implications are far more widespread, affecting the lives of everyone around the world- from cotton farmers in Texas to public health workers in Chicago. If nothing is done to change current emission levels, the number of days per year which exceed 100 degrees Fahrenheit, for example, will begin to increase dramatically, and if emissions are increased, many areas will even develop extreme conditions like those seen currently in Death Valley. Hayhoe’s goal is to demonstrate clearly that the only way to preserve the world for future generations is to significantly reduce dependence on inefficient means of getting energy and instead transition to cleaner renewable energy sources.

Editor's Note: These videos first appeared on the Nova program "The Secret Life of Scientists & Engineers".

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The origins of human chromosome 2: a brief review

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

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

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

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

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

Enter the Denisovans

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

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

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

Implications for understanding our “becoming human”

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

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

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

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

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

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

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

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

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

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

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

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

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

David Lack

Ornithologist David Lack

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

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

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

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

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

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

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

Large Cactus Finch on Española Island in the Galápagos Islands

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

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

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

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

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

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

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

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

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

Iconic Finches

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

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

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

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

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

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

Conclusion

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

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

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

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

For Discussion

Further Reading

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

Notes

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

Eugene Dubois

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

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

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

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

Figure 1: Dubois' Pithecanthropus erectus

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

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

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

Homo erectus across South East Asia:

Figure 2: Sangiran 17

Sangiran

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

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

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

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

Figure 3: Sambungmacan 3

Sambungmacan

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

Figure 4: Ngandong 6

Ngandong

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

Homo erectus in China

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

Lantian:

Figure 5: Lantian

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

Figure 5: Hexian

Hexian

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

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

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

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

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

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

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

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

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

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

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

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

Many people say that science and religion need to be even further apart. I disagree, however. And there are many scientists who agree with me.

I am a Christian. I believe that God is the ultimate reality and that the world, including me, was created by God. But this is not just an idle affirmation, a faith statement to be recited in church on Sunday. I find my experience of the world enriched in several ways by my belief in God.

For starters, my first contact with the world that God created is through its great beauty. I write these words from my desk in a sunroom on the back of my house. Outside my window a row of Newport plums is in bloom, their delicate pink flowers lighting up the landscape. My andromedas are also blooming. The dogwood, whose branches brush my window when the wind blows, is starting to bud. Directly in front of me the sun is coming up, visible through the forest. New spring foliage at the tops of the trees is becoming illuminated. In a few minutes I will have to pull my blind to keep the sun out of my eyes.

A choir of birds is singing, celebrating the arrival of the new day. I can tell from their joyous song that they must not be Red Sox fans. The sound of the birds is so welcome, in contrast to the traffic noise from the front of my house, which starts up shortly after the birds each morning.

Scientific explanations exist for all that I see and hear outside my window. And explanations can be proposed for why humans enjoy nature so much. But faith is God is not about explanations. We do not believe in God because we need to explain this or that feature of the world. That is what science is for. We believe in God because we see something deeper in the world, something that transcends the scientific explanations.

The experience of natural beauty is available to everyone, and only the flattest of souls cannot enjoy scenes like the one outside my window right now.

As a scientist, however, there are other layers to this experience. Underneath the artistic beauty of nature lies the deeper beauty of a system of natural laws. All the wonders in front of me are built from a few dozen different atoms -- hydrogen, oxygen, carbon, nitrogen. They combine and recombine to make life possible. Their molecular arrangements are the pixels of nature's most beautiful scenes.

These atoms are all built of protons, electrons, and neutrons. In all the atoms, electrons hum about tiny nuclear cores, following an amazing set of mathematical laws. I can still recall those giddy undergraduate days, decades ago, when I learned to solve the equations that specify what these electrons can do. The solutions were difficult and required the better part of a math degree to produce, but they were elegant beyond belief.

I remember working into the wee hours of the morning, losing track of time, hoping that I wasn't making mistakes along the way. And then finally a solution appeared on the paper in front of me that was so breathtakingly beautiful that I knew there was no way I had made a mistake. The solution was so simple. All you had to do was plug numbers into the final result -- simple integers like one, two, three -- and electronic arrangements would pop out. It was Sudoku on steroids.

The beauty of these mathematical patterns is a rich part of the scientific experience of nature. It is what draws people into physics and often turns them into detached and marginally functional mystics, like Newton and Einstein.

What seems the most remarkable of all, though, is the way that the whole system works together. That sun coming up in front of me is 93 million miles away. It takes eight minutes for the light generated by its fusion reactions to make the long trek to earth. Some of the light arriving outside my window is absorbed by chlorophyll molecules in the plants and becomes stored energy. Some of this energy was in the lettuce I ate last night in my salad. Now that energy is driving my metabolism, keeping me alive, letting me experience this new day, powering my fingers now on my keyboard. Some of the sunlight warms the ocean after a long New England winter, coaxing summer into existence. The light makes it possible to view the scenery outside my window. Everything I see becomes visible only when light strikes it.

I also note that this same multi-tasking sun provides the gravitational force that keeps the earth in its stable orbit, tracing out a mathematically perfect ellipse several billions times in a row.

The full experience of a new day is a complex mix of wonder and science, facts and beauty, mathematics and color. Science explains much of it, and what is left over is not so much in need of explanation as it is in need of celebration.

My belief in God provides a framework for this celebration. In some way that I cannot articulate, I praise God for each new day, dimly aware that I am sharing the experience with the artist who put it all in place and put me here to enjoy it.

This piece originally appeared April 21, 2010, on The Huffington Post.

Along the side of our patio in front of our family garden, I grow grapes. I was inspired to grow them from the tradition of my mother's homeland in Cyprus, where grapes, olives, figs and lemons adorn the patios of each house. I was challenged to grow them well by the words of Jesus in John 15: "I am the vine, you are the branches, I will prune you to produce much fruit." Pruning is the secret to successful grapes, but that's another story.

The point is that in tending that grape arbor and our family garden, and exploring the beautiful landscapes we are blessed with in Virginia, my wife Elizabeth and I, along with our three daughters, are in communion with the Creator and Sustainer of heaven and earth. That may sound like a lofty statement, but for me, nature, His created order, is where I find Him most personally. I have known and recognized this since I was a boy.

Though born in Richmond, I was raised in Portsmouth, Virginia, where my father and I would fish along the Elizabeth River and the Chesapeake Bay. With my friends, I hunted in the Great Dismal Swamp. My father grew up on my Grandpa's farm in Tennessee near Bristol and he took our family back there often. My grandfather was one of those vanishing breeds of men who had fidelity and love for the land. He was dependent on the land for his food and a few cash crops for income. He was intimately tied to the rhythms of the seasons and his work in the fields.

My grandfather and my aunts and uncles looked at this work as a partnership with the Lord. They taught me how to care for the land, as well as the names of plants that grew in the forests and along the streams that surrounded their farms. They also taught me skills that made me appreciate their way of life. Through these early experiences, I became fascinated with an essential question: What makes nature tick? I also developed an interest in the spiritual relationship between God and His creation. And so the journey began.

I took up the study of biology at Virginia Tech focusing on stream ecology, and then worked as a field biologist surveying rivers throughout the Southeast. Eventually, I returned to graduate school to study forest ecology in the Shenandoah National Park. My faith in the biblical account of creation was challenged by professors who taught evolution as the mode of creation of living things.

This challenge I brushed aside until I began teaching biology at a community college in Clifton Forge. The words in the textbooks and the words of Genesis took on new meaning. Did they contradict each other? Could all forms of life really evolve by chance? Weren't we created in His image? My students questioned me about this conflict and I started a search for the answers.

For several years I wrestled with these questions as an intellectual exercise. I began to make progress only when I started answering with my heart along with my head, aided by that other gift received from my parents, trust in the power of prayer. Looking back, this doubt and questioning, this need to have all the answers, made my faith real exactly as it taught me that I don't need to have all the answers: that is where faith comes in.

I do know with certainty that God created the heavens and the earth, and manages and sustains His creation even today. I cannot know with certainty how He did it with such precision and beauty. How God created is still a mystery that science, by its methods, tries to discover and cannot fully explain, and one that the Bible is mostly silent on.

To me, there should be no contradiction between science and the Bible. In the beginning, God was there and science cannot speak to that. It is by faith that I know that God created the world not by chance, but for his purposes and glory. The precision of natural order and its beauty have always focused me on the Creator, just as Paul states in Romans that all creation bears witness to God. The more I study nature and natural sciences, the more it drives me back to God who made all things.

In time, I was hired by The Nature Conservancy in Richmond as the ecologist and director of a new biological inventory for Virginia. Then another faith question came. Why did the Church not speak to the Christian practice of stewardship as it relates to creation? Why did many in my profession worship the creation and not the Creator?

I stumbled upon the work of Wendell Berry, who has since become one of my favorite authors. In a short essay he wrote in 1988 entitled God and Country, he said we must deal with the true meaning of Genesis 1:28 where God told Adam and Eve to "be fruitful and multiply and replenish the earth and subdue it." He was right. Berry noted that many people use the words "dominion" and "subdue" as "unconditional permission to use the world as they please." I came to realize, like many, that such an interpretation is contradicted by the rest of the Bible.

The ecological teaching of the Bible is clear. God made the world and it pleased Him. It is His and He loves it. He has never given up title to it. He wants us to take excellent care of it. In Genesis we see it in His instructions to Adam and Eve in the Garden; in Leviticus 20, we see it in the Sabbath year and the Jubilee—laws governing land use, land rest and God's ownership of the land; in Psalm 24 David affirms "the earth is the Lord's and everything in it"; Jesus, in Matthew 6, tells us not to worry, for if God cares for the birds and plants, he'll also care for you; and in Romans 8:19, Paul says the creation eagerly awaits freedom when right relationships will be restored.

Biblical ecology is really a moral understanding of what God expects of us in relation to the natural world, but also in relation to the other people with whom we share it. This kind of stewardship has only been recently talked about in the Church. It means careful management, not destruction and abuse. It is infinitely practical because a healthy planet is in our best interest (we depend on its fruitfulness, after all), but biblical stewardship is also an act of loving our neighbors as ourselves, of loving even our children and grandchildren, by leaving them a decent place to live.

Psalm 8 lays out a mystery that, with the rest of Scripture in mind, invites a response in action as well as praise: "When I consider the heavens, the work of your fingers, the moon and stars you have ordained, what is man that you are mindful of him?" After more than 20 years with The Nature Conservancy in Richmond, Elizabeth and I have made a home for our family and have a church home, as well—all places in which we can respond to that mystery by bearing fruit. And though my answering the call to use my talents and time in each of those realms branches in many directions, it is always rooted in my awe of God, who created and sustains the universe and seeks a relationship with us. It is a call I live out in my vocation of protecting and restoring the lands and waters in Virginia, and a call our family lives out in our garden, in our frequent excursions in the outdoors, our worship of the Lord in church and at home, and, yes, even in growing grapes.

Dr. Owen Gingerich is professor emeritus of astronomy and history of science at Harvard University. He grew up in a Christian home and attended a Christian college in northern Indiana that had a motto of “Culture for service”, something that was very important in thinking about what he might do with his life.

When it came time to go to graduate school, one of his science professors told him “If you feel a calling to go to astronomy, you should give it a try, because we shouldn’t let atheists take over any particular field.”

And so he went on to a career in astronomy. In the late 1980’s, Dr. Gingerich had a unique opportunity to give a lecture at the University of Pennsylvania on the topic of science and Christian faith. Since then, he’s been trying to help people better understand God’s creation. For example, God could have made the universe in many different ways, but given the particular way it appears, it suggests that we wouldn’t be here if the universe were not very, very old, because out of the big bang came hydrogen and helium, but not oxygen and the iron we need for our blood, for instance. Those things came from the interiors of giant stars and had to cook for long, long periods of time before we got those elements abundant enough for sustainable life. It’s a marvelous picture, and Dr. Gingerich is actively involved in telling people about it.

A member of a church that I was attending once told me that I was “giving bullets to the enemy” because I claimed to be a Christian and an Evolutionary Biologist. I responded (shamefully, with equally as little Christ-likeness) by saying that it was also possible to lead people astray by telling them that, to be a Christian, they had to dismiss scientific evidence in favor of something akin to fortune telling using sheep entrails—i.e. “Creation Science.” Understandably, this touched a nerve. Please don’t misunderstand me; I was not trying to be dismissive of his viewpoint, I was trying to be understanding, compassionate and loving. I confess to failing miserably at the attempt.

But you should not think that evolutionary biologist colleagues can be any less judgmental, or that I can be any more forgiving of their attitudes. That’s why when the evolutionary biologist accused me of having “no integrity” for saying that I could be both a Christian and an Evolutionary Biologist I responded that I was not the One he would have to answer to regarding his unbelief. I guess it isn’t surprising that that seemed to touch a nerve as well. For your information, I pray the same prayer for both my non-Christian, scientist colleague and my church acquaintance; that they both would come to the realization that we all need desperately God’s grace and forgiveness.

On the other hand, I must admit that in my least charitable moments I just pray that they would get a grip, start enjoying some hobby, or maybe a spouse or girlfriend/boyfriend, and in the process forget to accuse me, and others like me, of giving aid and comfort to those evil folks who stand on the other side of the philosophical fence. My prayer for myself is that my frustration over such interactions would leak quickly out the bottom of my left foot, never to return.

I really would like to be much kinder and gentler than the oft-times nasty, vindictive, hyperbolic tirades pulsating between the extreme elements of the so-named (by the other ‘side’) ‘spiteful, hell-bound evolutionists’ and the ‘brain-dead Christians.’ But it really is tempting to challenge the attitudes of the opposing evolutionist and creationist guerilla fighters mentioned above, and I suppose such an exposé could be both entertaining and enlightening. In fact, it might even cause my friends, who stand firmly in one camp or the other, to smile and maybe even take pity on us poor souls sitting on the razor wire fence between the warring factions.

That gives me an idea. Maybe my position is sort of like being a U.N. Peacekeeper in Lebanon. I mean you can’t get between the two opponents without getting shot at, you’re not supposed to shoot back, and you look somewhat silly in those powder blue helmets. In other words, no one takes you seriously, and your only useful role is as a negative example for parents to use: “Eat your broccoli and drink your milk, or you might grow up to be a U.N. Peacekeeper...or even a Christian Evolutionary Biologist.” The analogy of being a member of a mainly powerless peacekeeping force also illustrates how silly the “bullets to the enemy” accusation is. I mean why in the world would I prance (I am confident in my level of masculinity) into the camps of the vehemently-positive-of-their-correctness combatants, hand them ammunition and then prance (see above) back into no-man’s land all the while being shot at from both sides?

Hmmm. Maybe that is exactly what I am doing. I mean, look-it, very religious people who (at least according to my evolutionist friends) occupy the territory of mindless oafs see me as Satan’s Toady. To these religious adherents, I am Scut Farkus’ (a la A Christmas Story) right-hand man, Grover Dill: I have green teeth, dress in a James Dean-esque leather jacket, terrorize unsuspecting kids into submission (in my case, into believing the heresy of Evolutionary Biology), and am only brave when my enormous minder—made up of degrees, books, etc.—is starkly visible. As appealing as this image is to me, I really don’t fit the stereotype; my teeth are actually a shade of yellowy-brown due to my long-lasting love affair with espresso.

What about the opposing viewpoint of my hyper-enlightened, hyper-rational, hyper-intelligent, hyper-etc. evolutionist colleagues? Unfortunately, to them I am 1) suffering from a delusion – self-induced, or pathological, 2) a spy for those anti-evolution wackos, or 3) someone who just wants to be able to make loads of money from writing books and articles on how a person can be both a Christian and an Evolutionist. (O.K., so that last one is my idea.)

Some might conclude from the above that I, and others of my ilk, feel like a person from an ethnic minority at a skinhead convention—a bit vulnerable and a bit undervalued. Well then are Christian Evolutionary Biologists simultaneously heretical and ignorant? Realistically, if I am giving ammunition to each of two opposing factions, how then can I hope to be a card-carrying member of either? I guess my answer is that putting a bunch more cards into my wallet just increases the size of the lump I have to sit on. In other words, I either have to be content with a throbbing pain in my derriere, or I have to jettison trying to simultaneously please two groups of fairly discontented people. Christ talked about trying to serve God and the pursuit of money. I think that when I get depressed about not feeling a part of either of the groups that I truly like and understand—i.e., “Mindless Christians” and “Godless Evolutionary Biologists”—I am suffering from putting people ahead of God.

I intend this essay as a challenge to both myself, and anyone else interested enough to take the time to think about the various issues. The position of Christian Evolutionary Biologist continues to challenge me because I don’t see how all the pieces can possibly fit into a coherent picture. As someone who demands neat answers I find this frustrating and confusing. I do, however, believe that what I am outlining gives some sort of a platform for discussion, at least if we take Theodosius Dobzhansky’s words – quoted at the first of this essay – to heart. For this to happen, Christians need to refrain from using the Bible as a Biology/Geology/Chemistry/Physics textbook in order to prove to non-Christian Evolutionists that they (the Christians) are not unintelligent.

As an aside, Christians also need to quit trying to prove God’s existence through probability formulae. There is no danger of this outcome of course, but if we were able to prove God’s existence in this manner, then we would be God, and that would be a pretty disappointing turn of events. I really want to be careful here to not be ungracious, yet I have to say that misusing the Bible and attempting to prove God’s existence through cleverness tends to prove the non-Christian Evolutionists’ point...that some Christians—in their zeal to see themselves as triumphing over non-Christians—really can look pretty unintelligent.

In the same way, Evolutionists need to quit trying to convince people that understanding evolutionary processes is anywhere near as important as investigating the possibility of having a parent/child-type relationship with an omnipotent, omnipresent, omniscient God Who is able to judge people and send them to Heaven or Hell depending on whether or not they are members of His family. It flat won’t make a bit of difference if I work out the natural selection coefficients that were necessary to produce every species that ever existed if I end up denying God’s existence to my eternal regret.

The Apostle Paul wrote that Christians were people that should be pitied most if the basis of their religion (the resurrection of Christ) was found to be a hoax. In my weak humanity, I would have to disagree somewhat with this Pauline hyperbole. I would say that it is a whole lot better to have had a difficult time here on earth because you tried to live a “Christian life” and then die to realize that there is nothing on the other side (or actually not realize it because you aren’t there...well...you know what I mean) than it is to put your hope in your intellectual exercises and then die, come face-to-face with God, and thus discover that you weren’t nearly as clever as you supposed. I would suggest that the latter state would be infinitely and eternally worse than being a person from an ethnic minority at a skinhead convention.

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

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

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

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

Evolution: A Theory with Bite

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

Independent Lines of Evidence, but Contradictory Stories?

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

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

Signature in the SINE

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

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

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

For further reading:

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

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

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