In defense of paleontology

i-d12dbeb65eefa80515373c83b52b97d6-800px-Diplomystus_and_Knightia_Green_River_Fm_WY-thumb-500x335-47842.jpg


Fossil fish from the Eocene age Green River Formation in Colorado. From Wikipedia.


I am pretty tired of Richard Dawkins putting down paleontology. In his 2004 tome The Ancestor's Tale, as well as in his latest book The Greatest Show on Earth, Dawkins felt compelled to cast the fossil record as an unnecessary bonus when it comes to demonstrating the reality of evolution. "The evidence for evolution would be entirely secure," he asserts in the latter book, "even if not a single corpse had ever fossilized." While this statement contains a crumb of truth - we have learned much about evolution by studying living organisms - I cannot help but feel it snobbishly denigrates an entire field which has greatly influenced our understanding of evolution. This trend is hardly new.

In his 1919 appraisal of evolutionary science, A Critique of the Theory of Evolution, the embryologist Thomas Hunt Morgan damned paleontology with faint praise. No discipline more immediately demonstrated the truth of evolution than paleontology, Morgan wrote, but when paleontologists made any attempt to move beyond simply describing fossils they had a bad habit of concocting hare-brained evolutionary schemes:

My good friend the paleontologist is in greater danger than he realizes, when he leaves descriptions and attempts explanation. He has no way to check up his speculations and it is notorious that the human mind without control has a bad habit of wandering.

While perhaps a bit harsh, Morgan's criticism was not entirely without merit. Between the late 19th and early 20th centuries many paleontologists favored non-Darwinian evolutionary mechanisms, from ideas similar to those of Lamarck to the existence of internal driving forces which pushed animals towards particular end points (making extinct creatures failed experiments in a lineage's attempt to reach that goal). Nevertheless, even after paleontologists like W.D. Matthew, G.G. Simpson, A.S. Romer, and others cast out these ideas in favor of natural selection and the "paleobiological revolution" of the late 20th century, paleontology is still often cast as a science that can do little more than offer up proof that evolution occurred but never say anything more about it. In this dim appraisal of the field paleontologists should be content to describe their old bones and avoid theorizing, as if to say "Thanks for those transitional fossils; now go find some more and stop bothering the grown-ups."

This blinkered view ignores the importance of paleontology to the development of evolutionary thought. The similarity of fossils to living organisms inspired both Jean Baptiste Lamarck and Charles Darwin to begin considering how new species might be brought into existence over the course of time, and in an even more general sense the establishment of paleontology confirmed the existence of "lost worlds" filled with unfamiliar animals, all of which came into existence and were extinguished long before the emergence of our own species. Hence paleontology provided the background and historical context in which debates over evolution took place, and while it is true that Darwin could not present an array of minutely-graded transitional forms when he published On the Origin of Species in 1859, it is significant that he spent two entire chapters considering the implications of his theory for paleontology and vice versa.

That was over 150 years ago, of course, and despite the way it has been cast in several recent popular treatments of evolution, modern paleontology is about much more than providing fossilized confirmations of Darwin's view of life. Perhaps more than ever, paleontology has become a synthetic discipline which has incorporated aspects of genetics, evo-devo, and other sciences to not only identify transitions in the fossil record, but explain how they occurred. Nor has paleontology just been a consumer of ideas developed in other disciplines. The recognition of mass extinctions, evolution in the mode of punctuated equilibrium, the roles of contingency and constraint in evolution, and other important ideas have all emerged out of, or at least have been given more prominence through, studies of the fossil record.

I cannot claim to be an unbiased observer in this matter. I am enthralled by paleontology, and I feel that it often does not receive the credit it deserves. (Hence at least part of my motivation for composing Written in Stone.) This is an exciting time for the field, one in which paleontology is expanding to generate cross-disciplinary studies between laboratory and field-based science, yet it is too often cast as the never-ending search for more fossils and little else. This is a shame, especially because academic positions for paleontologists are becoming increasingly rare. Be it due to state budget cuts or the perception that paleontology is not a worthwhile pursuit, many museums and departments all over the United States are being closed down, meaning that it is more difficult than ever for paleontologists to find a job. While perhaps not intended this way, the continuing implication that paleontology is unnecessary to evolutionary studies perpetuates the image that it is nothing more than the collection and curation of fossils, and I fear that this further spurs the closure of opportunities for paleontologists to do their work. This is the sad paradox of modern paleontology, and I hope that these conditions soon change for the better.

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As G.G. Simpson himself said in 1944's "Tempo and Mode in Evolution": âExperimental biology . . . may reveal what happens to a hundreds rats in the course of ten years under fixed and simple conditions, but not what happened to a billion rats in the course of ten million years under the fluctuating conditions of natural history. Obviously, the latter problem is more important.â Substitute molecules for rats, and the point is still the same...

I don't see Richard Dawkins putting down Paleontology in the way that you say. I think his point is that we don't need fossils to explain evolution. However I do think that the fossil record puts 'the icing on the cake' as it were and to me shows that evolution should be considered a fact. All of the fossil evidence adds up to prove evolution is true. More and more fossil finds simply confirm this.

I do agree though that RD could make more of this fact rather than say that it is not required for evolution to be true.

I never thought of Dawkins as dismissing fossil evidence because as you say, it's very important for us to visually convey the theory of evolution, and to express subtleties that are not be apparent in the molecular evidence.

I didn't read that into RD's book at all! I think what he meant is that the "gaps in the fossil record" are one of the favorite soundbites in the anti-evolution crowd when trying to undermine evolution's scientific credibility (mainly because it's the most accesible dataset - they don't understand genetics). What RD was saying is that, even if gaps in the record were wider, or if we didn't have fossils at all, we still have enough compelling evidence from other sources to validate evolution as a scientific fact.

I'm all for scientific debate but this article seems to be seeing a conflict where there is none.

Admittedly I am interpreting things a little bit, and interpretations can differ, but I do think Dawkins has glossed over the importance and contributions of paleontology to evolutionary science. Paleontology is not just "icing on the cake" - it is an essential part of modern evolutionary science, and I take the suggestion that we don't really need it to demonstrate the reality of evolution as a bit of a slight (just as I would imagine geneticists would not be too happy if I said "We don't really need genetics to demonstrate the fact of evolution" in my book - what is the purpose of making such an argument at all?)

Obviously I singled out Dawkins here, but it is a trend that I have seen in many popularizations of evolution. Paleontology only comes up in the context of supplying transitional forms with no discussion of what we can tell about the way evolution works from the fossil record or the interdisciplinary studies now taking place. As I said in the post and in this comment, my opinion is obviously biased and my interpretation can be called into question, but I feel that Dawkins (as well as some other popularizers of science) have not done a very good job giving paleo its due.

A lot of people don't realize that paleontology is a predictive science. You can look for specific habitats of a specific age in the rock record, using knowledge of paleogeography, then go hunting for fossils you think will be there, whether they're the earliest turtles or a missing link or whatever. Paleontologists go hunting, not gathering.

I didn't read that as a put-down, either. After all, it goes the other way: without genetics, we'd have a perfectly good case for evolution just from fossil evidence. That doesn't really need to be said, though, because that actually WAS the case for the first couple centuries or so of biology.

i got a sense of a put down in AT. a very mild one, but one nonetheless. totally explicable in light of the normal contempt with geneticists have for paleontologists (though dawkins is an ethologist by training). kind of like the issues that molecular biologists had toward organismic guys.

I agree with many of the comments above - I don't think it was a putdown at all, or rather it was a putdown of the creationists.

Reading media reports and creationist nonsense, you would think that all evolution has got going for it is the fossil record. All RD was doing was righting the balance.

The fossil record remains an important part of the picture, as it always has been. I don't think RD would dispute this, though obviously I can't speak for him. The recent new find in South Africa just reinforces the significance of paleontology in tracing evolution including human evolution.

Yes, I think you have to understand RD's comment as a rebuttal of creationist's assumption that the fossil record is the only evidence Evolution's got going for it. In fact the whole book is about explaining all the different sources of evidence and how they fill eachother's potential gaps. He talks extensively about the importance of archeology and geology elsewhere in the book.

I can't attest to any potential hostility towards paleo on the part of Dawkins, but I can bear witness to the hostility that paleontology sometimes experiences in academia. When I was in graduate school (at a university that will remain nameless) it was mandatory to attend a guest lecture every Thursday. These speakers were invited by faculty, and reflected the diverse disciplines within the department, from geochemistry to planetary geology and yes, paleontology. These lectures were usually well attended, with virtually every graduate student showing up...except during the paleo lectures. Regardless of the particular topic, I never saw more than half of the department bother to show up for any particular paleo lecture. Whenever I would introduce myself to a new graduate student, I would listen with interest and enthusiasm as they described their projects and then watch their eyes glaze over the second I told them I was a paleontologist. This disinterest always puzzled me because my advisor was generally held in high esteem by the faculty and other students; his undergraduate courses were frequently filled to capacity within a day of the start of registration. So...why the lack of interest?

Just my two cents....

Brian, in comment #6 you wrote: Obviously I singled out Dawkins here, but it is a trend that I have seen in many popularizations of evolution.

Not just in evolution. A lot of scientists in other fields just don't think that palaeontology is very important or interesting. Perhaps the single most glaring example of this attitude I know of concerns the K-T extinction and the Alvarez "asteroid doomsday" theory for explaining it. Alvarez and his pals found the K-T iridium layer, found it to be ET in origin, and immediately leaped to the conclusion that the impact had caused the extinction. When palaeontologists tried to object, they were smacked on the nose and told "shut up, the real scientists have spoken, now accept it and go back to playing with your bones." Fossil evidence demonstrates conclusively (IMHO) that Asteroid Doomsday is fatally flawed, yet no one outside palaeontology seems to notice.

By wolfwalker (not verified) on 28 Apr 2010 #permalink

Brian, you're identifying a real rift between neontological and paleontological thinking, the argument arising from the premise whether fossil history versus molecular history has more to say in regards to the history, meaning, and mechanics of life itself. One argues that the other merely supplements it; a secondary synthesis is attempted by some, but not all, and even only in the very last few years have studies been attempting to integrate substantive molecular and fossil histories into a single narrative. Until then, enjoy the [very real] war between neontology and paleontology.

By Jaime A. Headden (not verified) on 28 Apr 2010 #permalink

wolfwalker (#14), I think you will find that the evidence for the K-T is well supported by the fossil evidence.

http://www.springerlink.com/content/vw75014157p2p278/

The link I've added provides excellent multi-proxy evidence for the K-T boundary and its association with the asteroid impact.

By DavePeterson (not verified) on 29 Apr 2010 #permalink

The fossil record is amazing and paleontology is very cool. This said, there is rarely if ever sufficient sample size for statistical analysis to differentiate selection from a random walk, when it comes to fossil material. There's only what, nine or so nearly complete Tyrannosaurus rex skeletons and about thirty incomplete specimens? Hardly an adequate sample size for reaching any firm conclusions about change over time due to selection. Even with thousands of specimens of fossil fish (such as the Knightia in the illustration), from varved sediments, which is as good as it gets in paleontology, selection can't at the p<.05 level account for the observed morphological change over time. Compare this inadequacy with observed evolution due to selection in bacterial cultures maintained in chemostats. One variable can be tweaked in such a bioreactor and evolution observed in real time. This being the case I can hardly take issue with Dawkin's assertion about the fossil record being "an unnecessary bonus when it comes to demonstrating the reality of evolution."

By darwinsdog (not verified) on 29 Apr 2010 #permalink

Alright! What happened to the rest of my post?

By darwinsdog (not verified) on 29 Apr 2010 #permalink

You make a lot of excellent points about paleontology's place in the history
of acceptance of evolution, Brian.

What I've found interesting about relating Dawkins' point is how many
lay people are surprised that understanding evolution isn't just about
fossils.

I've said similar things as Dawkins said. From now on I will be careful to avoid saying it in such a way as to give the idea I'm dissing paleontology in any way. I'm certainly not. It tells a wonderful story that we can't get in other ways.

Perhaps paleontology is akin to tracking animals. I don't need to see fox tracks to know foxes are in the area, but by following those tracks I develop a picture of the fox's behaviour, ecology, hunting area, patterns. Likewise with paleontology, we don't need to see fossils to know evolution is true, but the fossils tell us the story of how it probably happened, what arose, split, died out or continued.

It paints a picture we can't get any other way and as the story unfolds with each new find (or reexamination of old finds) how can anyone not be fascinated by this detective story? Just based on that I'm pretty sure RD isn't being condescending to paleontology, but I'd have to reread the sections in question again.

By Daniel J. Andrews (not verified) on 30 Apr 2010 #permalink

Dawkins, "The Ancestor's Tale," p. 456;
"Molecular clocks ultimately depend on calibration by fossils. Radiometrically calculated dates for fossils are accepted with the respect biology rightly bestows upon physics.... One strategically located fossil that confidently places a lower bound on the dating of an important evolutionary branch point can be used to calibrate a whole lot of molecular clocks...."

It seems pretty clear that Dawkins sees fossils as vitally important to understanding the history of life on earth. But on the religious question of whether evolution actually occurred (as opposed to the scientific question of exactly what happened when) fossils are just one of many lines of evidence. You don't need fossils to tell you you'd better do something about the pesticide you're using on the south forty when the bugs evolve resistance.

By hoary puccoon (not verified) on 01 May 2010 #permalink