The Blind Leading the Blind

Creationists spin-doctor the evolution of blind cave fish

Image: Jesus! vs. Darwin! by The Searcher
It's a tired old routine, yet time and again the same argument is taken off the shelf, dusted, buffed and then presented with a sly smile as if it were something new. Evolution, it's asserted, is only progressive and builds on earlier adaptations in its march forward through natural history. Therefore, if there is any evidence that a species adapted "backwards" it must mean that natural selection is flawed. However, the fallacy in this argument is that natural selection has nothing to do with progress, it's merely one of the mechanisms by which species successfully adapt to their environment. Genetic mutations don't have a direction in mind when there's a mistake in transcription or as a cosmic ray collides with a nucleotide of cytosine. If the organism succeeds once this genetic alteration occurs, they'll reproduce and spread the mutation further. It says nothing about a march of progress.

Those who oppose evolution without bothering to first understand it have repeatedly hailed this fallacy as a triumph. It was the centerpiece of the laughably bad polemic Icons of Evolution by intelligent design advocate Jonathan Wells (a detailed review can be found here). Now the same sickly horse has again been prodded out to market despite how often such duplicity has been exposed in the past.

In the latest edition of Current Biology (subscription required), Richard Borowsky found that blind cave fish whose genes for vision have mutated over the course of evolutionary history could have their vision returned by interbreeding with other blind cave fish with differently mutated genomes.

According to the review in Science Daily:

The study examined four populations of blind cave fish, Astyanax mexicanus, which inhabit different caves in northeast Mexico. Blind for millennia, these fish evolved from eyed, surface fish. The researchers' genetic analysis showed that the evolutionary impairment of eye development, as well as the loss of pigmentation and other cave-related changes, resulted from mutations at multiple gene sites.

In order to gauge how genetic make-up could bring about the restoration of vision, the researchers created hybrids of the different cave fish populations. Among these various hybrids, they found that nearly 40 percent in some hybrid crosses could see.

Fascinating stuff. These results support the view that different species each adapt to their environment in unique ways, precisely as evolutionary theory predicts. However, the results must have been a little too uncomfortable for intelligent design creationists because immediately both Uncommon Descent and Creation Ministries International (which produces the young Earth themed Journal of Creation) hit upon the news as evidence that evolution must be wrong. Dr. Carl Wieland, writing for Creation Ministries, objects to this evidence of multiple evolutionary trajectories and insists that:

It would not take long at all, once a group of fish are cut off from the daylight by some geological circumstance, for an eye-losing mutation to be established by natural selection as described.

Of course, if Dr. Wieland had bothered to read the actual article (rather than merely the press reports that creationists are so fond of) he would have found that Astayanax mexicanus “evolved from eyed, surface-dwelling forms which only reached the area in the mid-Pleistocene,” that is, between 600,000 to 1 million years ago. How does Borowsky know this? This is where references matter. Earlier research by Ulrike Strecker and colleagues, published in Molecular Phylogenetics and Evolution (subscription required) showed that mutations occur in freshwater fish at a rate of 1.5% per million years. By analyzing the differences in cytochrome b genes between currently living species and then dating the nearest common ancestor of each in the fossil record, Strecher et al. proposed that Astyanax first arrived in the Yucatan no earlier than 900,000 years ago, just as Borowsky states. How can Wieland be so certain that “it would not take long at all” for such mutations to occur? Not presenting any evidence to back up his assertion we can only wonder how he determined this. But then, already walking down a blind alley, Wieland goes on to make matters even worse by asserting that:

Cave fish have arisen by processes that in fact demonstrate the opposite [of natural selection]—deterioration of function, consistent with the ‘natural’ direction of genetic change in a fallen world.

Here the good spin-doctor rests on the fallacy that has failed so miserably for so long: if evolution is about building up then mutations that result in deterioration must prove evolution is false. But even more than this, the fact that these cave fish have lost their vision supports Dr. Wieland's contention that the sin of man has affected all of creation. If you’re a little confused then you’re in good company. Apparently Wieland (and other Young Earth Creationists in general) think that Adam and Eve’s violation of God’s dictates resulted in the beginning of genetic change. Prior to the “fall” there was no aging, no genetic deterioration and no death. Far from revealing additional evidence to the already weighty tome of evolutionary theory Wieland instead sees evidence of God’s divine plan. And Creationists accuse scientists of imposing their views on nature? Of course, why God in his infinite wisdom would feel it necessary to put out the eyes of a few Mexican fish to punish humans for their hubris is anyone’s guess. But I suppose that's why it's called blind faith.

References:

Borowsky, R. (2008). Restoring sight in blind cavefish. Current Biology 18: R23-R24

Strecker, U., Faundez, V.H. and Wilkens, H. (2004). Phylogeography of surface and cave Astyanax (Teleostei) from Central and North America based on cytochrome b sequence data. Molecular Phylogenetics and Evolution 33(2): 469-481. doi:10.1016/j.ympev.2004.07.001

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Religion Masquerading as Science

Your Sunday Skepticomic from Cox and Forkum



To view last Sunday's comic click here.

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Primate in Chief

Your Sunday Skepticomic (artist unknown) with no offense meant towards other primates.



To view last Sunday's comic click here.

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Situational Science Man

Your Sunday Skepticomic from Doonesbury.

(click image to enlarge)


To view last Sunday's comic click here.

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Intelligent Design's Selective Moral Outrage

James Watson, Ann Coulter and the tolerance of bigotry

Image: Voices for Change Committee

The nineteenth-century American author and moralist T.S. Arthur once wrote, “We are judged by the company we keep.” While we can doubt the veracity of this statement in every particular (after all, this famous advocate against the evils of alcohol was a friend of Edgar Allen Poe who probably died from drink) it’s certainly true in the case of people who condemn in others what they tolerate amongst themselves.

Denyse O’Leary, Canadian journalist and Intelligent Design creationist who writes at William Dembski’s site Uncommon Descent, has taken great umbrage with James Watson for yesterday’s racist comments, and for good reason. Just days after insulting the intelligence of Rosalind Franklin (the geneticist he refuses to credit as one of the discoverers of DNA) Watson claimed that he was “inherently gloomy about the prospect of Africa” because:

"All our social policies are based on the fact that their intelligence is the same as ours – whereas all the testing says not really . . . people who have to deal with black employees find this not true."

This is patently offensive nonsense. How such a formerly brilliant mind could believe such absolute hogwash is a depressing thought. However, it takes tremendous hypocrisy on the part of Uncommon Descent to paint these absurd remarks with a broad brush and vehemently assert that “legitimized racism is an inevitable consequence” of evolutionary theory. Considering that they have such high standards, one would naturally assume they’d call out such vile language in those they agree with as well as those they don’t.

Predictably this isn’t the case. Ann Coulter (who has said about Muslims that “We should invade their countries, kill their leaders and convert them to Christianity” - also see below) has been praised repeatedly on the same website which now claims such profound moral indignation.

William Dembski himself has stated that Coulter “will propel our issues in the public consciousness like nothing to date” and was “happy to report that I was in constant correspondence with Ann” while writing her book Godless, in which she defends the racist social science propagated in The Bell Curve.

O’Leary likewise accuses Richard Dawkins of being anti-Semitic for making passing reference to the successful “Jewish lobby” in Washington. But when Coulter announces that Jews are nothing but “imperfected Christians” and that the entire religion of Judaism should be thrown away there is strangely no mention, no moral outrage, no condemnation that “legitimized bigotry is an inevitable consequence” of conservative Christianity (which I don’t think it has to be, though believers often attempt to dissuade me of this view).

James Watson deserves the public thrashing he’s currently receiving, and I’m glad that Uncommon Descent will agree that such racist comments are despicable. However, I think this hypocrisy represents a fundamental difference between Intelligent Design advocates such as O’Leary and Dembski and those they intend to malign. Immediately after Watson’s diatribe was uttered, prominent evolutionary scientists condemned his opinions and were rightly offended by his remarks. I’m still waiting for similar actions to be taken by those pillars of tolerance over at Uncommon Descent.

UPDATE: For more on this see Mark's terrific post today at Denialism Blog.

Additional quotes by Ann Coulter:

"Jihad monkey talks tough; jihad monkey takes the consequences. Sorry, I realize that's offensive. How about 'camel jockey'?"

"I'm all for public flogging. One type of criminal that a public humiliation might work particularly well with are the juvenile delinquents, a lot of whom consider it a badge of honor to be sent to juvenile detention. And it might not be such a cool thing in the 'hood to be flogged publicly."

“Thank God the white man did win or we would not have the sort of equality and freedom, or life, that we have now.”

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Intelligent Design and Pseudoscience

Michael Behe joins the ranks of UFO conspiracy theorists



The Panda’s Thumb has linked to an excellent analysis by Duquesne University biologist David Lampe on the productive scientific work of Intelligent Design proponent Michael Behe. While ID has long been criticized for not generating testable hypotheses (and therefore not involving the scientific method) Dr. Lampe has now shown that Behe has done almost no science at all since his first book Darwin’s Black Box was published in 1996.

Behe has been described as “a scientist of the first rank,” however a scientist is judged by how often he or she publishes in peer-reviewed journals and how often other researchers cite those publications. In a simple test Lampe compares Behe’s work with that of the widely acknowledged “scientist of the first rank” Sean Carroll.

Since 1996 Behe has published only a single peer-reviewed scientific article, and that article didn’t even mention “intelligent design.” Furthermore, Behe’s work since 1996 has been cited a total of 99 times (mostly for his first book) and of those the majority of the citations are negative views of his work or they don’t appear in scientific journals. This leaves 11 favorable citations in nine years of a work that wasn’t peer-reviewed.

In contrast Sean Carroll has published 36 primary research articles in peer-reviewed journals that were cited 1,508 times and nearly all of them in the scientific literature.

In summation, Lampe states:

I conclude, based on the evidence, that Michael Behe is obviously not a scientist of the first rank and appears not to be doing any serious work at the present time. More to the point, ID creationism is not an important idea in science. Science is a meritocracy where ideas earn their place. Until ID shows it can be used as a productive idea to perform scientific work it should not be presented as a viable alternative to well-established evolutionary theory. Academic freedom issues are simply not germane in this context. Short-circuiting the normal process used to establish the scientific ideas we teach to students is simply dishonest.

The evidence speaks for itself. Intelligent Design has had an appalling scientific legacy. Now, before someone claims that Intelligent Design is a new line of inquiry that takes time to gain acceptance, let me point out that Sean Carroll’s work is in the brand new field of evo-devo and has had no difficulty swaying his colleagues based on the evidence alone. ID advocates have tried to sneak in through the back door by appealing to courts and politicians instead of through the legitimate main entrance of the scientific literature. This speaks volumes about their scientific integrity.

Intelligent Design proponents are nothing but pseudoscience hucksters who attempt to trump experimental evidence through emotional appeals and untested criticism. When confronted by their lack of scientific rigor they’ll whine about a vast conspiracy that prevents them from publishing their work. This is the same position that so-called ufologists and other proponents of new age pseudoscience espouse. In the relatively near future Michael Behe’s work will be dumped in the bin housing such other erroneous claims as von Daniken’s Chariots of the Gods and Velikovsky’s Worlds in Collision. I hope it’s sooner rather than later.

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But What About the Crocoduck?

Michael Behe's hypothesis still pseudoscience


Creationist argument for how evolution couldn't happen.

The California Literary Review has an interview with Intelligent Design guru Michael Behe. The comments have some decent information (especially about his Dover testimony that was referred to as “breathtaking inanity” by the conservative judge). The rest of the interview is filled with garbage like this:

Is there any way to test the concept of a designer? Is there any evidence of his or her actions interceding in the development of life on earth?

Well, it depends on what you mean by “test” and “evidence”. If you and a friend walked by Mount Rushmore, even if you had never heard of it before, you would immediately realize that the faces on the mountain were designed. Not for a moment would you think they were the result of random forces such as wind and erosion. Your conclusion of design would be certain, because you would see how well the pieces of the mountain fit the purpose of portraying an image.

So now Intelligent Design advocates have descended to the same silly argument that Ray Comfort and Kirk Cameron trot out. If it looks designed, it must be. Problem solved. Never mind that structures such as Mount Rushmore are incredibly rare and violate the natural processes of geology while all biological systems show evidence of common descent. Behe should join the dynamic duo on their next adventure.

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Unintelligent Designs

Your Sunday Skepticomic from David Horsey.


To view last Sunday's comic click here or search the web for skepticomic, coined first right here.

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The Primate Diaries appears in the Chronicle of Higher Education

Issues over Young Earth Creationism being promoted at university website.



As I posted earlier, University of North Carolina at Chapel Hill computer science professor David A. Plaisted has been using his department website to promote Young Earth Creationism in the public schools. Join the debate at their blog.

According to William Allan Kritsonis, PhD:

CREATIONISM has always caused much debate. We should encourage discussion on both sides of the issue.

What a marvelous idea! Let's make that standard policy across the sciences. What would that look like I wonder?

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Shamanic Visions of Selective Sweep

The evolution of schizophrenia reveals the nature of contingency


Shaman from the Mbukushu of Namibia

J.B.S. Haldane famously quipped that, if there is a God, he’s inordinately fond of beetles. Others may choose to be somewhat less kind and argue that, with around 2 million species of the beastly little things, such a design could only be the product of a disorganized mind. Perhaps that’s the solution Intelligent Design proponents have been looking for: God is schizophrenic! However, as it turns out, schizophrenia is the perfect metaphor for how our evolutionary history is not a well ordered and implemented design, but is rather full of twists and turns and ill-adapted consequences that are best explained through the contingencies of natural selection.

Several years ago Robert Sapolsky suggested that genes promoting schizophrenia may have been selected for in human evolution because some of them conferred benefits that outweighed the 1% of people worldwide that were disabled by the disorder. Like the sickle-cell trait that confers resistance to malaria (so long as you don’t receive two recessive alleles and develop full fledged sickle cell anemia) a partial schizophrenia may be beneficial in some way. He observed that relatives of schizophrenics have a high likelihood of “schizotypal personalities,” or a mild form of the disorder that just makes these people a little strange and allows them to see the world in a unique way. What if, he wondered, schizophrenia maintained itself in human populations because of selection for schizotypal personalites? As luck would have it, for a hundred years anthropologists had observed such individuals thriving in nearly every society they encountered: shamans.

As Sapolsky stated in 2003 while accepting an award from the Freedom from Religion Foundation:

The critical thing with schizotypal shamanism is, it is not uncontrolled the way it is in the schizophrenic. This is not somebody babbling in tongues all the time in the middle of the hunt. This is someone babbling during the right ceremony. This is not somebody hearing voices all the time, this is somebody hearing voices only at the right point. It's a milder, more controlled version.

Shamans are not evolutionarily unfit. Shamans are not leaving fewer copies of their genes. These are some of the most powerful, honored members of society. This is where the selection is coming from.

Sapolsky hypothesized that the evolution of schizophrenia was ultimately a byproduct of selection for beneficial cognitive adaptations. In the early edition of Proceedings of the Royal Society: Biological Sciences Bernard Crespi, Kyle Summers and Steve Dorus have found that schizophrenia evolved in human populations in just this way. By analyzing specific selective sweeps (or the non-coding regions of DNA that get “pulled along for the ride” when a coding region undergoes a beneficial mutation) they’ve determined that 28 of 76 genes that have been linked to schizophrenia have undergone positive selection during human evolution. These 28 genes are all closely linked to cognitive abilities involved in complex thought.

As the authors summarized their findings:

[G]enetic liability to schizophrenia has evolved as a secondary consequence of selection for human cognitive traits. . . The selective forces underlying adaptive evolution of these genes remain largely unknown, but these findings provide convergent evidence consistent with the hypothesis that schizophrenia represents, in part, a maladaptive by-product of adaptive changes during human evolution.

In other words, the same genes that make us so smart and our species so successful can sometimes (specifically, about 1% of the time) result in a debilitating mental disorder. The other 99% of us are doing so well that these genes continue to perpetuate themselves. In the evolution of complex thought, schizophrenia was accepted as a devil’s bargain.

Whether sexy shamans are the ultimate source for this selection or not remains to be seen. However, what Crespi, Summers, Dorus and Sapolsky have emphasized is that evolution is a messy business and is rarely as straightforward as we might assume. There is no long-term view or plan in the evolutionary narrative. Organisms make do with the raw materials they’re born with and the occasional beneficial mutation simply adds additional supports to a jury rigged foundation. God, if such a being exists, must be inordinately fond of such haphazard construction, his “design” is chock full of them.

Reference:

Bernard Crespi, Kyle Summers and Steve Dorus (2007). Adaptive evolution of genes underlying schizophrenia. Proceedings of the Royal Society: Biological Sciences doi:10.1098/rspb.2007.0876

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Parsimony and the Origin of Life in the Universe

The all-too-common descent to arguments from personal incredulity


The micro-manager at work in His workshop (Monty Python's The Meaning of Life).

Intelligent Design creationists are fond of using the strategy of denial based on personal incredulity. “I can’t explain how protein motors with multiple parts could evolve so, therefore, no one can and Darwin was wrong.” However, while Michael Behe may not have been able to explain the bacterial flagellum others seemed to have no difficulty. That Behe abandoned this centerpiece in his latest book suggests that he was smart enough to realize he was wrong.

William Dembski and friends haven't figured that out yet and proudly display the flagellum as their website image at Uncommon Descent. Today they've found a new fallacy to flog with the recent Biology Direct paper on multiverses as an explanation for the improbability of life's origin.

Origin of life is a chicken and egg problem: for biological evolution that is governed, primarily, by natural selection, to take off, efficient systems for replication and translation are required, but even barebones cores of these systems appear to be products of extensive selection. . . In an infinite universe (multiverse), emergence of highly complex systems by chance is inevitable. Therefore, under this cosmology, an entity as complex as a coupled translation-replication system should be considered a viable breakthrough stage for the onset of biological evolution.

Invoking the argument of parsimony, or the idea that the simplest explanation requiring the fewest number of steps is the better explanation, BarryA asks:

The question for the class today is which is the most parsimonious hypothesis: One designer or infinite universes?

BarryA is correct in bringing up parsimony to critique this paper but he's ludicrously foolish in assuming his position is somehow a less complex explanation. The designer God that ID proponents taut is a micro-manager that assembles bacterial power supplies, initiates the catalyzing cascade in blood clots and directs the maddeningly complex interactions of organic evolution (Behe accepts human ancestry with apes but thinks God intended humans to emerge). This would mean that the designer is ultimately more complex than the design itself.

I'm glad BarryA isn't teaching my class, or any class for that matter. It's bad advice to propose a hypothesis that is more complicated than the question you're trying to answer. All this hypothesis does is lead to the next question of what or who created the designer? The more parsimonious hypothesis IS that the universe always existed. BarryA can't explain how this could be (and frankly I can't either) so he descends to the position of personal incredulity.

However, invoking the infinite multiverse as an explanation for how life evolved is the same misguided argument that has been used for years as the anthropic principle. It basically boils down to the statement, "Life exists because we happened to live in a universe with physical laws that made it possible for life to exist." It's no more clever than that, just fancied up with metaphysical flourishes.

Rather than invoking an infinite multiverse as an explanation for a coupled translation-replication system, I think that a more parsimonious explanation is that we don't yet fully understand the conditions under which RNA trancription could evolve from basic amino acids in the chemical soup of early Earth. You shouldn't rush to a "God of the gaps" or an "everything is possible with multiverses" argument until you're sure all other explanations have been eliminated.

I only wish I could use this multiverse explanation for difficult problems I'm working on. "The least-squares regression line is correct for this data set because we live in a universe where least-squares regression lines are able to be correct." Brilliant!

Reference:

Eugene V. Koonin (2007). The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life. Biology Direct 2:15. doi:10.1186/1745-6150-2-15

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"Intelligent" Design and Magical Thinking

You Sunday Skepticomic from The New Yorker.



To view last Sunday's comic click here.

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A Three Million Year Walk Through Egypt

New hominid footprint has Intelligent Design advocate stumped


Zahi Hawass_________________Cast of fossilized footprint________

This is very confusing. The Scubaredneck (seriously, that's his name) writing at Uncommon Descent posted this article about a new fossil footprint in Egypt that might be older than the earliest evidence of Australopithecus afarensis. But he just posted the story as is from Reuters. Did he forget to inject his Intelligent Design message to show they’d predicted this all along? Is there something significant about Egypt having evidence of hominids earlier than Ethiopia? Are they changing their tactic to suggest that evolutionary anthropologists have been too conservative in their estimates about the age of A. afarensis? I really don’t understand why this would be posted on William Dembski’s page. Can someone explain it to me?

CAIRO (Reuters) - Egyptian archaeologists have found what they said could be the oldest human footprint in history in the country’s western desert, the Arab country’s antiquities’ chief said on Monday.

“This could go back about two million years,” said Zahi Hawass, the secretary general of the Egyptian Supreme Council of Antiquities. “It could be the most important discovery in Egypt,” he told Reuters.

Archaeologists found the footprint, imprinted on mud and then hardened into rock, while exploring a prehistoric site in Siwa, a desert oasis.

Scientists are using carbon tests on plants found in the rock to determine its exact age, Hawass said.

Khaled Saad, the director of prehistory at the council, said that based on the age of the rock where the footprint was found, it could date back even further than the renowned 3-million year-old fossil Lucy, the partial skeleton of an ape-man, found in Ethiopia in 1974. (emphasis added by The Scubaredneck)

He probably thinks that Reuters' use of the word "human" means modern humans. I can see him grinning with excitement as he posted the story. If only a dinosaur footprint had been just next to it he might have had an aneurysm.

In all seriousness, the indentations at the heel and big toe are consistent with the footprints from Laetoli and could be further evidence of early hominid bipedalism. This would provide additional evidence that our ancestors walked upright before large brains had evolved. However, the assessment that this dates from earlier than 3 million years ago was based purely on one person's interpretation prior to a full analysis (notice how there were two age estimates in the same article), so I look forward to this evidence being presented in a journal. Because, unlike the Intelligent Design advocates, I don’t take random media clips as evidence for anything.

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Apparently Not Very Long

Leakey confirms what Intelligent Design already knew


One (of many) adaptive radiation diagrams of hominid evolution.
From Scientific American, January 2000, “Once We Were Not Alone”, page 60

Yesterday (at 3:19 pm) I posted commentary about the recent finds from Koobi Fora suggesting that Homo habilis and Homo erectus lived during the same period for at least part of their existence (however, see the terrific critique of the study at Anthropology.net). This put the final nail in the coffin for an idea that had been losing support for thirty years: that human evolution was a linear progression. I ended the post with the question:

How long do think it will take before the Creationist/Intelligent Design crowd jumps on this story to claim they were right all along?

Answer: 22 hours 51 minutes.

The Discovery Institute has now announced that the Nature study only reveals "one of Jonathan Wells' points in chapter 11 in Icons of Evolution." See, they knew all along. Wait, did they say Jonathan Wells? Jonathan Wells was arguing that human evolution occurred through a bushy distribution rather than a linear progression? Jonathan Wells who stated "my prayers convinced me that I should devote my life to destroying Darwinism" was actually a closet supporter of adaptive radiation?

Perhaps I've misjudged the man. Wells does quote the adaptive radiation argument for human evolution presented by Stephen Jay Gould:

“Humans represent just one tiny, largely fortuitous, and late-arising twig on the enormously arborescent bush of life.”

But then he takes great umbrage with the statement. So where exactly did Jonathan Wells predict the recent findings from Koobi Fora? There's quite a lot about the Piltdown Man hoax, however surprisingly little detailed analysis of actual fossils. I'd be very interested to hear the answer to that.

How long do think it will take before the Discovery Institute gets back to me on that question? I'm guessing somewhat longer.

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A Family Reunited

Homo habilis and Homo erectus shared the family dinner table, but probably ordered different meals.



Two new fossil discoveries from Kenya described in the current issue of Nature show that Homo habilis and Homo erectus lived contemporaneously. According to today’s New York Times:

Scientists who dated and analyzed the specimens — a 1.44 million-year-old Homo habilis and a 1.55 million-year-old Homo erectus — said their findings challenged the conventional view that these species evolved one after the other. Instead, they apparently lived side by side in eastern Africa for almost half a million years.

The conventional view has been that Homo habilis was the ancestor of H. erectus and that there was a linear progression along that particular evolutionary branch.

This interpretation has always been suspect to me for, as a good student of evolution knows, linear and evolution rarely go hand in hand (and progression never). Evolutionary history is a complex branching tree without direction or purpose. This doesn’t imply randomness (please take note creationists), but rather demonstrates how organisms adapt to their local environments instead of progressing to some ultimate goal.

The fact that the two hominid species lived together in the same lake basin for so long and remained separate species, Dr. Meave Leakey said in a statement from Nairobi, “suggests that they had their own ecological niche, thus avoiding direct competition.” For example, the two may have had foraging and dietary differences.

In any case, Dr. Leakey said, “Their co-existence makes it unlikely that Homo erectus evolved from Homo habilis.”

What this could imply is sympatric speciation from a common ancestor, in which a subpopulation of early Homo adapted to a different ecological niche and remained reproductively isolated from the main population. The later descendants of these subpopulations became habilis and erectus. Another possibility is that a geographic barrier isolated these two subpopulations long enough for them to adapt along separate trajectories. Later, a million years later or so, when this barrier no longer existed the two species then interacted but were distinct enough from each other that they didn’t compete over the same resources.

The new findings, Dr. Lieberman said, highlight the need for obtaining more fossils that are more than two million years old. In addition, he said, they show “just how interesting and complex the human genus was and how poorly we understand the transition from being something much more apelike to something more humanlike.”

How long do you think it will take before the Creationist/Intelligent Design crowd jumps on this story to claim they were right all along?

Have you made your guess? For the answer click here to see if you were right.

UPDATE: For an excellent review (and critique) of this Nature article see Anthropology.net

Reference:

F. Spoor, M. G. Leakey, P. N. Gathogo, F. H. Brown, S. C. Antón, I. McDougall, C. Kiarie, F. K. Manthi & L. N. Leakey (2007). Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya. Nature 448: 688-691.

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Behe admits ‘Intelligent Designer’ is God on The Colbert Report

Stephen Colbert, more than any other late night talk show host, has used his alter ego’s ditto-head spin-zone to bring evolutionary scientists to millions of viewers. His interview with Richard Dawkins is one of the best episodes I’ve seen (and I haven’t missed a single one). So I was acutely eager to watch Intelligent Design proponent Michael Behe on Thursday night’s show.

In classic form Colbert opens up the interview by judging the book by its cover (he doesn't read books, he feels them). Reading from the subtitle The Search for the Limits of Darwinism, Colbert asked “Should all science begin by looking for where to limit a theory?”

Behe was naturally stunned. Because as a biochemist he knows (or at least he should) that science only operates when it pushes boundaries and asks tough questions that can be tested experimentally. Behe, instead, waffled by suggesting that because no one in Darwin’s era understood the workings of the cell that, therefore, Darwin is incomplete.

That may be the first thing that Behe has been right about. Darwin, by himself, is incomplete. Without Mendel, without Fisher, without Dobzhansky and Haldane and Mayr Darwin’s theory wouldn’t be valid. These researchers, and many more in the 150 years since Darwin, have stood on the shoulders of a giant in order to see further than Darwin could alone. That is the process by which science operates.

Behe then suggested that Darwin will be overthrown by a new theorist the same way that Newton was by Einstein. This would make Behe a poor physicist the same way he’s a poor biologist. Einstein didn’t overthrow Newton, he refined Newton. Newton’s laws continue to be valid. Einstein was able to construct a testable hypothesis to demonstrate what gravity was, rather than just how it operated (i.e. Newton’s laws of motion). That’s how all great science operates.

What Behe did not show, and what none of the Intelligent Design proponents show, are the testable hypotheses they’ve constructed to demonstrate the existence of a designer. It’s not enough to find some collection of molecules somewhere that evolutionary biologists haven’t looked at yet and declare, without evidence, that evolution couldn’t have constructed them. You design an experiment and you show that you’re right. Spewing hot air may be enough for the pundits that Colbert is mocking, but it’s not enough for the scientific method.

In the end Colbert cleverly voiced the reasons why those who believe in God want Intelligent Design to be true. As science has progressed over the centuries it has explained away the great mysteries of the unknown, the traditional domain of God (or the gods), making His kingdom smaller and smaller.

“It’s time for God to fight back,” Colbert demanded, knowing that we’re in on his joke. Behe took the bait and responded, “It turns out He has,” thus admitting that he’s always had a theological purpose behind his crusade against evolution. Unfortunately, if God did select Behe to be the crusader for this cause, His powers of omnipotence have been greatly exaggerated.


Update: Other reviews can be found here, here and here.

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Life Lessons - Dr. Lummaa's Response

A few weeks ago I called out Bruce Chapman, President of the Discovery Institute, for insulting the work of biologist Virpi Lummaa. Dr. Lummaa found support for the grandmother hypothesis to explain why humans go through menopause. See my earlier post "Life Lessons" here.

Dr. Lummaa contacted me with the following response:

Dear Eric

I must say that when I read the title of your email, my heart turned around and I was scared to read what an earth is going on. We recently published a paper in PNAS about the effects of male co-twin testosterone in utero on their sisters, and I have had lots of positive letters from the twins themselves since the publication of the paper... but now I thought someone must have got offended.

But it was far more amusing, thanks so much for forwarding this to me. And many thanks for your reply too. I doubt nothing is going to convince these guys though, and if their arguments are that pathetic then I can only laugh.

best wishes,

Virpi

Dr. Lummaa is still waiting for your apology Bruce. If you'd like to give Mr. Chapman your views on attacking a biologist without bothering to understand her work, his e-mail address is bchapman@discovery.org

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Dentists Against Darwin

The Discovery Institute was proudly touting an anti-evolution group calling themselves Physicians and Surgeons for Scientific Integrity. According to DI:

they have 264 members from 15 different countries and are planning a number of major events in the next 18 months, including a series of public events in Spain this January, titled "What Darwin Didn't Know."

Funny thing is though, when I looked at the list of members the largest percentage (after family practitioners) are dentists! While I'm sure that dentistry school is rigorous, last I checked they don't do any research in evolutionary biology. They should though, if this dentist's ignorance is any indication:

I honestly don't think that wisdom teeth are good examples of evolution. I'm a dentist and deal with them all the time, and my feeling is that it's more a mix of genes that causes wisdom teeth problems. You inherit large teeth from dad and small jaws from mom... now you're getting surgery to have them removed because they don't have room to come in.

The reason I don't get the evolution argument is because there is no selective pressure applied to the teeth in question. In order for this to be true, those without wisdom teeth would have a greater chance of survival than individuals that have them.

Actually, he should probably retake Biology 101 first. Large teeth from dad and small jaws from mom?! Wow. Wisdom teeth are vestigial traits that are lingering remains of our evolutionary history. Scienceline goes into more depth about them here.

Just for fun, next time you're strapped into the dentist's chair ask whether or not Australopithecus afarensis was plagued with wisdom teeth. Have they even heard of Australopithecines? Also ask them what their view is of Super String Theory. I'm sure they'll be able to give a detailed answer. Afterall, they're scientists.

You've got to give it to the ignorant apes over at DI though. They'll do anything to push their imagined controversy.

To find out about other vestigial traits that show our evolutionary legacy Mark Wagner has a nice listing here.

We'd better watch out though, some of these dentists can get a little vicious.

Note to my dentist: I think dentists are wonderful and I value your very necessary skills and service. Please don't use the drill.

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Bonobo (Re)Visions

Commentary over the New Yorker article distorts and misrepresents the evidence.



As expected, the apologists for unreason who promote Intelligent Design have jumped on the recent article in the New Yorker about bonobos. This inspired me to write at more length about the article since this is a species I've studied closely for the last two years. Denyse O'Leary at Uncommon Descent uses the article to proudly declare that "Apes R Not Us, and we have to get used to it."

First off, even if bonobos turned out to be the most vicious beasts ever to be described by humankind it wouldn't change the fact that we share between 98.6% to 99.4% of our DNA with the genus Pan (the latter figure is based on genes responsible for brain tissue). We are apes, every last one of us hairless fools.

Second, while the popular view of bonobos has sometimes exaggerated their peaceful characteristics, the New Yorker article is being touted as though the reported bonobo social life has been a scientific fraud. As O'Leary states at her primary blog:

all along primatologists have had an agenda to try to prove that humans are not condemned to be brutes because bonobos are, like, nice.

There's a big difference between determining that popular misconceptions are incorrect and claiming that scientists are fabricating evidence. Gottfried Hohmann has been working for many years to try and uncover the mystery of the elusive bonobo. As reported this year in the journal Nature in reference to Hohmann's research:

Whereas violent encounters are the norm in the chimp society, conflicts such as that observed at Lomako are rare in bonobos. Perturbations to bonobos' social order are generally defused through sexual acts, often in homoerotic encounters between females.

There is a distinct difference between chimpanzee and bonobo social behavior, in the field and in captivity. As highlighted by bonobo expert Frances White and discussed in my earlier article, unrelated bonobo females will form cooperative partnerships to defend against aggressive males. This is unheard of in chimpanzees. Furthermore, it should be noted, that aggressive bonobos are positively timid when compared to chimpanzees in full battle mode.

However, the New Yorker article ignores this aspect of bonobo sociality to set up an ad hominem mode of argument. By attempting to show that Frans de Waal (who hasn't done field work with bonobos and has never claimed to) exaggerated bonobo cooperation they imply that such cooperation may not exist. This rhetorical approach may have worked with some of the more uncritical folk at Uncommon Descent, but you could build a monument with the crates of bad argument and misinformation that they employ on a regular basis.

For example, the New Yorker article makes a point of noting that captive bonobos could be more promiscuous than wild bonobos. Citing Craig Stanford, a primatologist I greatly respect:

“Stuck together, bored out of their minds—what is there to do except eat and have sex?”

However, if this were the case why wouldn't captive chimpanzees be doing the same thing? When you compare captive chimps and captive bonobos you find striking differences. But, assuming that captive animals are therefore bad examples, why would the New Yorker then use a captive example to suggest bonobos are just as violent as chimpanzees?

. . . at the Planckendael Zoo, near Antwerp. “I once saw five female bonobos attack a male in Apenheul, in Holland,” he said. “They were gnawing on his toes. I’d already seen bonobos with digits missing, but I’d thought they would have been bitten off like a dog would bite. But they really chew. There was flesh between their teeth.

Couldn't one respond to this anecdote by saying:

“Stuck together, bored out of their minds—what is there to do except eat and fight?”

I'm very pleased that the New Yorker has chosen to highlight bonobos and in general I think the article was very good. However, uncritical readers may take the author's approach of pushing controversy to attract attention (a tactic the Intelligent Design crew knows only too well) as demonstrating more than it has.

As more evidence comes in more will be known about our other evolutionary cousin. However, there is no disagreement among primatologists that bonobos are a unique species with characteristically unique social interactions, even among those who think the distinction has been exaggerated. As the New Yorker article highlighted from those who have spent the most time in the field:

“With bonobos, everything is peaceful,” Takeshi Furuichi, a Japanese researcher who worked with Kano at Wamba, told me. “When I see bonobos, they seem to be enjoying their lives. When I see chimpanzees, I am very, very sorry for them, especially for the high-ranking males.”

To paraphrase my hero T.H. Huxley, I only wish I was more closely related to either of these species than I am to the ignorant apes over at Uncommon Descent.

Update: Frans de Waal has responded to the New Yorker article at eSkeptic. I discuss how bonobos highlight the politics of human nature at The Primate Diaries.

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Lord of the Placenta - Part II

As highlighted in my previous entry, Dr. David Menton, writing for the anti-evolution group Answers in Genesis, claims that the placenta proves God’s handiwork. This is an empirical claim and can therefore succeed or fail based on his evidence. But he doesn’t provide any evidence. What he does provide are statements praising how amazing the placenta is (a claim with which I completely agree) and presumes that such amazement could only be produced from a divine origin.

The next time you experience the joy of a baby’s birth, thank the Lord for providing this selfless placenta. And above all, reflect on the fact that our Creator, who at the time of childbirth so mercifully spares the mother from a fatal loss of blood, did not hesitate to shed His own blood in death to save us from sin, death, and the power of the devil.

By Menton’s logic "The Omnipotent Obstetrician" personally intervenes in every pregnancy and, though he provided this selfless placenta out of his love, he presumably then finds the very organ (“the issue of her blood”) loathsome after she gives birth and thinks the new mother should be shunned for several weeks (Leviticus 12:1-5). But then, God’s not too big on anything relating to the birth canal, particularly menstrual blood.

Writing in the aptly named journal Placenta, J.C. Cross and associates published an evolutionary review article entitled "Genes, Development and Evolution of the Placenta." As you probably guessed, the placenta shows no evidence of being divinely inspired but is in fact closely related to structures traced back to egg-laying animals. The chorioallantoic membrane forms the placenta in mammals but also exists, in simpler form, in birds and reptiles. In birds it lies just beneath the eggshell and is integral for gas exchange and the transport of calcium.

If the placenta were so unique, as Menton suggests, we would expect that there would be unique genetic instructions specifying it’s divine role. What we find, however, is just the opposite. Placental genes are a recycled set of instructions for other systems. As Cross et al. explain:

“[E]volution of the placenta among vertebrates did not involve invention of an entirely new set of genes. Rather, nature has re-used existing pathways for functions common to other systems.”

However, this distraction ignores a far more interesting issue than whether or not God places his finger inside every womb. The evolution of the placenta exposes the importance of chemical imprinting and helps to explain why we find ourselves attracted to some people and not others.

As mentioned before, the mother’s body reacts to the implanting blastocyst as a foreign invader (hardly representing an omnipotent intelligence) in what is called an antigenic response. It has been demonstrated experimentally that the larger this antigenic difference is between parents the larger both the placenta and fetus end up being. The genes coding for this antigenic process are known as the major histocompatibility complex, or MHC. Individuals with different MHCs have characteristically unique smells that, while not obviously different on a conscious level, seem to serve a remarkable role in who we view as attractive, or rather, smell as attractive.

As described in New Scientist Swiss researcher Claus Wedekind determined that women were most attracted to the smell of used T-shirts from men who had significantly different MHCs from themselves. This finding was paralleled in rat studies that showed the same phenomenon. The evolutionary logic of this result is simply that variation of immune system genes would benefit parents by confusing those pathogens that have adapted to their own MHCs. Pathogens adapt rapidly and host organisms must constantly be on their toes if they want their progeny to have the same chance they did. Like the Red Queen of Alice in Wonderland, to win the race of evolution you have to run as fast as you can just to stay in the same place.

But is it demonstrated that similar MHCs actually result in greater risk during embryogenesis? In an ironic twist it turns out that it was a deeply religious group that helped reveal this evolutionary process in action. Geneticist Carole Ober from the University of Chicago conducted a study investigating this question of similar MHC effects by getting detailed gynecology information from 111 Hutterite women (a religious sect akin to the Amish). Out of 251 pregnancies, 27 women had experienced miscarriages. The highest miscarriage rates were in those women whose husbands shared the same MHC genes at 16 specific sites, and those that shared just some of these genes were at a higher rate than couples who shared none. Furthermore, since the Hutterites don't use birth control or deodorant, Dr. Ober could be sure that she was witnessing MHC-scent selection in action.

As remarkable as it may seem, B.O. serves a useful purpose. Females demonstrate that they have the ability to clue in on the chemical traces of immune system genes that will confer greater protection during embryogenesis and improved reproductive success. By selecting men who have unique MHCs from themselves women are sniffing out an evolutionary successful strategy.

How small and creatively lethargic Dr. Menton’s theistic hypothesis turns out to be when compared to this remarkable evolutionary insight. It’s unfortunate that Answers in Genesis encourages their members to remain intellectually inbred, but it’s the lack of Dr. Menton’s academic integrity that is truly depressing. By ignoring the scientific literature of his own field and claiming to find answers about embryology from a 6,000 year old collection of mythology he disregards the noble pursuit of genuine science and encourages his readers to remain intellectually stagnant. God, if such a being existed, would be greatly disappointed by such a waste of intellectual capital painstakingly invested through millions of years of natural selection.

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