Darwin is already dead, and we know it

I strongly disagree with the arguments of this essay by Carl Safina, “Darwinism Must Die So That Evolution May Live”, even while I think there is a germ of truth to its premise. It reads more like a contrarian backlash to all the attention being given to Darwin in this bicentennial of his birth. The author makes three general claims that he thinks justify his call to “kill Darwin”.

The first is a reasonable concern, that “equating evolution with Darwin” is misleading and can lead to public misunderstanding…but then Safina charges off into ridiculous hyperbole, that scientists are making Darwin into a “sacred fetish”, and creating a “cult of Darwinism”. It’s simply not true. I go through this every year, when I’m off to give a talks about Darwin around the time of Darwin Day, and there’s no deification going on anywhere. I talk about the central principles of Darwinism, which are still valid, but I also point out that he got many things wrong (genetics is the most vivid example), and that the science has advanced significantly since his day. I’ve talked to many other scientists who do the same sorts of lectures, and nobody portrays him as Saint Darwin.

As for equating evolution and Darwin, I deny that, too. I reject the label of “Darwinist” because my interests in the field are so remote and alien from what Darwin did that we really don’t have much in common — I care about evo-devo and molecular phylogenies and gene regulation and signal transduction, none of which invalidate Darwin’s ideas about selection and change and common descent, but which are such distant derivations of 19th century science that if Darwin were handed one of the papers in the field, he would find it incomprehensible. Again, this is a common experience among my colleagues: we respect Darwin as the discoverer of a set of general core principles, principles that have stood the test of time and are still incredibly useful, but we’ve moved on.

Safina makes a second and very common error: he claims that Darwin didn’t say anything new, anyway. There is a strange historical industry dedicated to finding omens and portents in other people’s writings that preceded Darwin, and it is entirely true that ideas like the transmutation of species were bubbling up all over the place in pre-Darwinian Europe. You can also find short passages in the works of virtually unknown authors that even hint at the process of selection. Darwin’s grandfather, Erasmus, was known as a bit of a heretic who contemplated the unity of all life, and Robert Chambers published his theory of evolution, Vestiges of the Natural History of Creation, in 1844, and of course Wallace was the co-discoverer of the idea of natural selection. If there had been no Darwin, his theory would still have emerged out of the ferment of biological thought going on in that century. But he still deserves full credit. Darwin is the man who realized the grand import of the idea; this was no casual mention of an interesting possibility, but a profound recognition that his explanation for the origin of species was going to have a sweeping effect on science and society, and a determination that he would document it thoroughly and well. Darwin also explained the concept lucidly, and with volumes of evidence, to such a degree that Thomas Huxley would say “How extremely stupid not to have thought of that!” upon learning about it.

Respect for Darwin is as much for the disciplined and scientific way he addressed the problem as it is for the discovery itself. When we celebrate Darwin, we are not cheering for a man who got lucky one day, but for someone who represents many of what we consider scientific virtues: curiousity, rigor, discipline, meticulous observation, experiment, and intellectual courage.

Safina’s third complaint is that we’ve discovered so much more since Darwin, that “Almost everything we understand about evolution came after Darwin, not from him”. This is trivially obvious. We could say similar things about Galileo, Newton, Boyle, Dalton, Lavoisier, Dalton, Mendel, any scientist of the past you can name. Mendel, for example, is a fellow I spend a week discussin in my genetics course to explain the simplistic basics…and then I spend the rest of the semester explaining that all of his postulates are so loaded with exceptions that they are often completely false in many real-world genetic situations. Yet at the same time his principles represent a powerful starting point for deciphering the complexities of genetics. Shall we throw Mendel out of the history books because 143 years of progress have reduced his seminal work to a relatively tiny blip in the volumes of evidence since?

Safina is taking a deeply anti-historical position, and I would go so far as to call it an anti-scientific one, as well. Science is all about the evidence for what we know, and explaining how we know it; announcing that Darwin must go is to throw out the foundation of our discipline, and teach disrespect rather than appreciation for our origins. It’s also damaging to public education: we can explain Darwin’s insights to the lay public, but it’s almost impossible to explain the details of modern research without relating it to the central questions that Darwin formulated 150 years ago.

So, obviously, don’t canonize, beatify, or apotheosize Darwin … but don’t throw him out, either. He is (not was) important.

Futurists make me cranky

And I don’t want to hear you complaining that everything makes me cranky! I get especially grumpy about armchair futurists making pronouncements about biology when they don’t know a thing about it.

Chairman and CEO of Biotechonomy, Enriquez says that humanity is on the verge of becoming a new and utterly unique species, which he dubs Homo Evolutis. What makes this species so unique is that it “takes direct and deliberate control over the evolution of the species.” Calling it the “ultimate reboot,” he points to the conflux of DNA manipulation and therapy, tissue generation, and robotics as making this great leap possible.

The day may come when we are able to take the best biology of the known animal kingdom and make it part of our own. This isn’t just about being a bit stronger, or having perfect eyesight our whole lives. All of our organs and limbs have weaknesses that can be addressed, and there are also opportunities to go beyond basic fixes and perform more elaborate enhancements. At a private lunch on Thursday, Enriquez spoke of a young girl who, after suffering a knee injury, received tendon replacement therapy centered around tendons grown in a lab. It not only fixed her knee, but made it stronger than normal. Later in life as she pursued life as a professional skier, he coach actually asked that she have the same surgery on her other knee to increase her abilities.

Every species is new and unique. Humans have some unusual specializations, but it doesn’t warrant his misplaced enthusiasm. Every species also takes control over its own evolution, in a sense; individuals make choices of all sorts that influence what will happen in the next generation. You could rightly argue that they don’t do it with planning and intent, but I have seen nothing that suggests that our attempts to modify our species, low tech and high tech together, are any wiser or better informed about the long-term consequences than those of any rat fighting for an opportunity to mate. We do what we do; don’t pretend it’s part of a long term plan that is actually prepared for all of the unexpected eventualities.

And then, of course, what does he talk about? Phenotypic patchwork! That isn’t evolution at all. That girl’s children will have whatever tendons her genetics grant them, without regard for the surgeon’s tinkering. Then he has the gall to claim that this warrants the designation of a new species? Hah. I wear eyeglasses. I declare that I am a member of Homo oculis! I read and communicate with text, so I’m now a member of Homo literatus! I’ve had my appendix removed, therefore I am part of the bold vanguard of Homo sanscecum!

And don’t get me started on Ray Kurzweil. That guy is bonkers.

Jerry Coyne has a blog

I know! It’s hard to believe! Why, any of the riff-raff can just charge in and start a blog anymore. You write a book or a few, do some internationally recognized research in evolution, and suddenly you get cocky and think you have the talent to write a blog. Back in the day when I started in this, I had to struggle with none of that. And I liked it!

Despite his awesome handicaps, it is a pretty good blog.

I especially like this image from his book, Why Evolution is True(amzn/b&n/abe/pwll):

So…no transitional forms, huh? Look at that australopithecine between modern Homo and Pan. It’s definitely not a chimp — the pelvis alone would tell you that — yet it’s also definitely far from fully human. Very cool.

Maiacetus

My teaching schedule this semester is a major time-suck; I’m teaching genetics and all of its associated labs (you really don’t want to know how much prep time goes into setting up fly labs), I’m doing some major revision of the content this year, and I’ve got this asymmetric schedule that packs everything into the first half of each week. So I simply have to protest when those evil (Stein was right!) scientists announce a major discovery on a Tuesday, which just happens to be the very worst day of the week for me. They’ve gone and found another important whale transitional fossil, Maiacetus, and I’m just going to have to tell you to go read a bunch of other fine blogs that already have it covered.

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(Click for larger image)

Skeletons of the Eocene archaeocete whales Dorudon atrox and Maiacetus inuus in swimming pose.

(A, B)- Dorudon atrox (5.0 m; 36.5 Ma) based on UM 101222 and 101215 [11] in lateral and dorsal views, respectively. (C, D)- Maiacetus inuus (2.6 m; 47.5 Ma) based on male specimen GSP-UM 3551 in lateral and dorsal views, respectively.

It’s beautiful. It’s clearly adapted for aquatic life, but it has another revealing feature: this specimen was pregnant at death, and the fetus is oriented for a head-first birth, which is not good for birth at sea (the head would pop out, baby would take its first breath, and drown before the tail emerged), so this animal would have had to give birth on land.

But like I said, you’ll have to read Carl Zimmer, Ed Yong, Brian Switek, or Greg Laden this time around for all the details. Or read the paper yourself! It’s freely accessible.

Darwin 200

A few of us wild and crazy evo people, including Richard Dawkins, wrote up pieces for an issue of the BBC Focus magazine. You’ll find me arguing with Steve Jones about whether evolution has stopped, Richard Lenski is highlighted, and Carl Zimmer makes an appearance. If you’ve got a flash player, you can read it online right now. It’s pretty good stuff, if I do say so myself.

Durston’s devious distortions

A few people (actually, a lot of people) have written to me asking me to address Kirk Durston’s probability argument that supposedly makes evolution impossible. I’d love to. I actually prepared extensively to deal with it, since it’s the argument he almost always trots out to debate for intelligent design, but — and this is a key point — Durston didn’t discuss this stuff at all! He brought out a few of the slides very late in the debate when there was no time for me to refute them, but otherwise, he was relying entirely on vague arguments about a first cause, accusations of corruption against atheists, and very silly biblical nonsense about Jesus. So this really isn’t about revisiting the debate at all — this is the stuff Durston sensibly avoided bringing up in a confrontation with somebody who’d be able to see through his smokescreen.

If you want to see Durston’s argument, it’s on YouTube. I notice the clowns on Uncommon Descent are crowing that this is a triumphant victory, but note again — Durston did not give this argument at our debate. In a chance to confront a biologist with his claims, Durston tucked his tail between his legs and ran away.

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Speaking of media mangling…

The cover story of New Scientist asks, “Was Darwin wrong?”, as if this were surprising news (he was wrong about many things) or as if the discovery of new details would somehow demolish the whole structure of evolutionary theory. I’ll let Larry Moran take care of this one.

It’s a symptom of creationist influence that journals would think that hyping a story that “150 year old theory gets revised!” is newsworthy. And, of course, the creationists are eating it all up.

Sharon Begley, how could you?

Usually, Begley is reasonably good on science, but her latest piece is one big collection of misconceptions. It reflects a poor understanding of the science and of history, in that it confuses long-standing recognition of the importance of environmental factors in gene expression with a sudden reinstatement of Lamarckian inheritance, and it simply isn’t — she’s missed the point of the science and she has caricatured Lamarck.

Some water fleas sport a spiny helmet that deters predators; others, with identical DNA sequences, have bare heads. What differs between the two is not their genes but their mothers’ experiences. If mom had a run-in with predators, her offspring have helmets, an effect one wag called “bite the mother, fight the daughter.” If mom lived her life unthreatened, her offspring have no helmets. Same DNA, different traits. Somehow, the experience of the mother, not only her DNA sequences, has been transmitted to her offspring.

That gives strict Darwinians heart palpitations, for it reeks of the discredited theory of Jean-Baptiste Lamarck (1744-1829). The French naturalist argued that the reason giraffes have long necks, for instance, is that their parents stretched their (shorter) necks to reach the treetops. Offspring, Lamarck said, inherit traits their parents acquired. With the success of Darwin’s theory of random variation and natural selection, Lamarck was left on the ash heap of history. But new discoveries of what looks like the inheritance of traits acquired by parents–lab animals as well as people–are forcing biologists to reconsider Lamarckism.

She’s describing real and interesting phenomena, but it isn’t new and it isn’t revolutionary. These are results of plasticity and epigenetics, and we aren’t having heart palpitations over them (you’re also going to have a difficult time finding any “strict Darwinians” in the science community who are even surprised by this stuff). We load up pregnant women with folate and maternal vitamins and recommendations to eat well, and we tell them not to get drunk or smoke crack for a few months, because it is common sense and common knowledge that extra-genetic factors influence the health and development of the next generation. Genes don’t execute rigid, predetermined programs of development — they are responsive to the environment and can express radically different patterns in different contexts. The same genes build a caterpillar and a butterfly, the difference is in the hormonal environment that selects which genes will be active.

It’s the same story with the water fleas. Stressed and unstressed mothers switch on different genes in their offspring epigenetically, which lead to the expression of different morphology. It’s very cool stuff, but evolutionary biologists are about as shocked by this as they are by the idea that malnourished mothers have underweight babies. That environmental influences can have multi-generational effects, and that developmental programs can cue off of the history of the germ line, is not a new idea, especially among developmental biologists.

This is just wrong on evolution:

Water fleas pop out helmets immediately if mom lived in a world of predators; by Darwin’s lights, a population of helmeted fleas would take many generations to emerge through random variation and natural selection.

It misses the whole point. The population of water fleas have a genetic attribute that allows the formation of spines under one set of conditions, and suppresses them under others. This gene regulatory network did not pop into existence in a single generation! If it did, then Begley would have a big story, evolution would have experienced a serious blow, and we’d all be looking a little more carefully into this ‘intelligent design’ stuff. The pattern of gene regulation was the product of many generations of variation and selection; only the way it was expressed in a phenotype experienced a shift within a single generation.

It’s also not Lamarckism. It’s another of those short and simple-minded myths perpetuated by high-school textbooks that Lamarck and Darwin had competing explanations for the same phenomena. They did not. This story of giraffes stretching their necks is an example of the purported inheritance of acquired characteristics … and here’s some headline news, Darwin proposed exactly the same thing! Darwin did not have a solid theory of heredity, and he himself proposed a mechanism of pangenesis which permitted the inheritance of characters by use and disuse and by injury or malformation. The key difference is that Darwin proposed that these variations could lead to the formation of new species; Lamarck believed in the fixity of species, and thought that a species would merely express a constrained range of forms in differing environments.

Both were wrong. A concept called the Weismann barrier emerged in the late 19th century, which suggested that the only influences that can be transmitted across generations are those that affect the germ line, the cells that give rise to sperm and egg, and that modification of the somatic tissues alone would not propagate. This is correct, and it’s still true: nothing in these reports suggest anything but that when perturbed by environmental stressors, gametes can switch on different genetic programs.

I think epigenetics and plasticity are important and play a role in evolution, certainly, but these kinds of elaborations on how cells interact do not imply in any way that there is a revolution in evolution, or that evolutionary biology has had it all wrong, or that this is heresy in progress. It’s also annoying to see all the vague handwaving about discrediting a “Darwinian model” — what Darwinian model? These discoveries are about mechanisms of genetic inheritance, and Darwin didn’t have a valid mechanism in the first place. In that sense, the only real heresy that counted was Mendel’s.