Category: anthropology

Will humans become two subspecies?

April 12, 2014 • 7:47 am

UPDATE: I’ve heard from Dr. Curry about this piece; he’s appalled that it was published and explains the situation:

I’m sorry that you had to waste some of your valuable time dealing with the old news story about the future of human evolution. The story purports to be about my ‘research’ on the future of human evolution; it is in fact a PR stunt by the television company Bravo. The real story is that, back in 2006 I was commissioned by Bravo to write an essay on the future of humanity. The essay was science fiction, intended to illustrate some aspects of evolutionary theory to an audience of television executives. It was not serious academic research, let alone a prediction about our actual future(!). However, Bravo put out a sensationalist press release about the essay, portraying it as science fact, and this press release was subsequently reproduced by the media (including the BBC). I watched in horror as the story spread around the world, and I am equally horrified each time the story bubbles up on the ‘most read’ list on the BBC homepage (as it does every few years, for reasons that are mysterious to me, as it did again the other day, hence your flurry of emails). As I am sure you can imagine, this is a recurring professional nightmare for me; and I am grateful to you for correcting some of the misunderstandings that the story has generated.

________

I haven’t read the paper that this BBC article refers to, nor do I know whether it’s even been published in the scientific literature, but several readers sent me this piece and wanted my take on it. Since it’s from 2006, I’m not sure why several readers sent it simultaneously.

The piece at BBC News is given the provocative title, “Human species may split in two.” And the theory floated in that piece, by Dr. Oliver Curry, a lecturer at the Institute of Cognitive and Evolutionary Anthropology at the University of Oxford and a research associate at the London School of Economics, seems deeply unsound: in fact, not even wrong.

Here’s how the BBC describes his “theory,” but again, if there’s a paper about it (one isn’t mentioned), I haven’t read it. All the article says is that Curry’s views were presented on a “men’s satellite TV show”:

Evolutionary theorist Oliver Curry of the London School of Economics expects a genetic upper class and a dim-witted underclass to emerge.

The human race would peak in the year 3000, he said – before a decline due to dependence on technology.

People would become choosier about their sexual partners, causing humanity to divide into sub-species, he added.

The descendants of the genetic upper class would be tall, slim, healthy, attractive, intelligent, and creative and a far cry from the “underclass” humans who would have evolved into dim-witted, ugly, squat goblin-like creatures.

. . . Further into the future, sexual selection – being choosy about one’s partner – was likely to create more and more genetic inequality, said Dr Curry.

The logical outcome would be two sub-species, “gracile” and “robust” humans similar to the Eloi and Morlocks foretold by HG Wells in his 1895 novel The Time Machine.

. . . He carried out the report for men’s satellite TV channel Bravo.

I see no evidence that humanity will divide into two moieties in this way. In fact, intermarriage between humans will become more prevalent with greater migration between countries, creating genetic admixture between all kinds of genetically different populations. I’m curious how Curry manages to conclude that the human species is—or will be—splitting into two groups that will remain genetically and reproductively distinct, and that there is a bimodal distribution of matings, with attractive, creative, and tall humans on one end and short, squat, and ugly ones at the other. Is there any evidence of this happening now? Not that I know of.

Further, even if there were assortative mating for looks (and I suspect there is), it’s neither complete or associated with intelligence. Where are the data showing not only bimodal mating for height and attractiveness, but that those traits are strongly associated (for a strong association is needed to split the species) with intelligence?

There is simply no data to butress these speculations, which get press only because they’re sensationistic, smacking of 1984.  Any tendency for such assortative mating wouldn’t create bimodality unless it was mandated by the government, for there’s sufficient gene flow between his dichotomous categories (attractive people of one sex marrying not-so-attractive people of the other, and so on) that this kind of “splitting” will not occur.

Curry goes on about receding chins, our loss of capabilities due to medical technology that allows the medically deficient to breed, and so on, but I’ll ignore that for the nonce. He adds this:

But in the nearer future, humans will evolve in 1,000 years into giants between 6ft and 7ft tall, he predicts, while life-spans will have extended to 120 years, Dr Curry claims.

Physical appearance, driven by indicators of health, youth and fertility, will improve, he says, while men will exhibit symmetrical facial features, look athletic, and have squarer jaws, deeper voices and bigger penises.

Women, on the other hand, will develop lighter, smooth, hairless skin, large clear eyes, pert breasts, glossy hair, and even features, he adds. Racial differences will be ironed out by interbreeding, producing a uniform race of coffee-coloured people.

This is again insupportable. 1000 years is only about 30-40 human generation, and if we are supposed to increase a foot in height by then, there would have to be pretty strong directional selection for height (or sexual selection practiced by both sexes). Again, I don’t know of any evidence for a higher reproductive output of people whose genes make them taller. We have no such data, nor do we know how much of height difference between human populations is based on genetic versus environmental differences. Since World War II, for example, the Japanese have increased several inches in height, but that change is due entirely in improvement of diet, as there’s only been one or two generations since then and nutrition has improved markedly. As for those squarer jaws, longer penises, and pert breasts, that’s just bunk. As far as I know, we have no data showing reproductive advantages (actually offspring number) accruing to men or women with those features.

The stuff about human morphology becoming more uniform over time is one thing that Curry probably got right (even a blind pig can find an acorn). Certainly humans are moving around more now, and people from different ethnic groups are intermarrying, evening out the lumps in the landscape of human morphology.  We all know of “hybrids” between people of different ethnic groups; I see them all the time among my students: children of Asian/Caucasian marriages, for instance. And you can often recognize them because their facial features and hair color are an admixture. But I don’t think we’ll be uniform in even a millennium.

And really, penis length? What data do we have that men with larger generative organs leave more offspring? Curry’s talking through his hat here.

This kind of unsupported speculation gives evolutionary biology a bad name.

 

 

Jane Goodall apparently guilty of plagiarism and sloppy science writing

March 27, 2013 • 6:17 am

Jane Goodall’s observations of the chimps at Gombe is perhaps the most famous work in primatology in the 20th century, and she’s rightly famous for her meticulous observations, her absolute dedication to her fieldwork, her discovery of many traits in our closest relatives that were thought unique to humans, and her tireless work on biological conservation (now 78, she still travels 300 days a year raising money and consciousness). My admiration was only slightly tempered when I found out recently that she was a goddie, and has spoken many times about her faith and the lack of conflict between science and religion.

But nobody, no matter how loved or revered, is immune from criticism; and in the case of Goodall, an iconic figure in primatology, the criticism has become particularly serious. She’s now accused of not only plagiarizing from other sources in her new book, Seeds of Hope (a book about the importance of plants, co-authored with Gail Hudson), but also of conveying inaccurate information about GMO food—serious accusations for a professional scientist.

The accusations were first leveled in an article by Steven Levingston in the March 19 “Book” section of The Washington Post, after a prospective reviewer (a botanist) noticed the problems and declined to review the book.  Levingston highlights the following instances of plagiarism (i.e., unattributed copying):

  • In the book, Goodall extols the benefits of sustainable farming. She expresses her shock at learning of dangerous conditions for workers who harvest tea.“According to Oxfam,” she writes, “a British nonprofit agency working to put an end to poverty worldwide, the spraying of pesticides on tea estates is often done by untrained casual daily-wage workers, sometimes even by children and adolescents.”That paragraph appears word for word on the Web site of Choice Organic Teas, a company dedicated to ethical labor practices. Choice Organic Teas was selected in 2010 to carry the Jane Goodall “Good for All” brand on a new line of products, and it donates a slice of its profits to the Jane Goodall Institute.
  • Goodall explains the toxic dangers in some detail, writing: “Most of these chemicals — such as Aldrin 20E, Carbofuran 30, Endosulfan 35 EC, Malathion 50 EC, Tetradifon 8 EC, Calixin 80 EC — are listed as hazardous and toxic, and a number of them are banned in Western countries. Despite dangers of exposure to these poisons, the workers are frequently barefoot and in shorts rather than protected by recommended aprons.”
    This material is replicated nearly verbatim from the same Web site page. Both passages also appear in nearly identical language on other organic tea Web sites and in the 2008 book “Big Green Purse: Use Your Spending Power to Create a Cleaner, Greener World” by Diane MacEachern. The language can be traced to a 2002 draft report, “The Tea Market — A Background Study,” which lacks an authorship credit.

The following is especially bizarre. Wikipedia? Really?

  • “Seeds of Hope” contains language from Wikipedia in its discussion of 18th-century Philadelphia botanist John Bartram, who shipped boxes of seeds to Europeans. Goodall writes: “ ‘Bartram’s Boxes,’ as they came to be known, were regularly sent to Peter Collinson for distribution to a wide list of European clients.”The Wikipedia entry reads: “Bartram’s Boxes as they then became known, were regularly sent to Peter Collinson every fall for distribution in England to a wide list of clients.”

  • Goodall marvels at the majesty of trees. “In ancient Egypt,” she notes, “the sycamore was especially revered — twin sycamores were believed to stand at the eastern gate of heaven through which Ra, the sun god[,] came each day.”

    Nearly identical words are found on a Web site called “Find Your Fate,” which covers astrology, numerology, palm reading and matters relating to love and life.

  • The phrasing Goodall uses to describe the tobacco habits of Indians in South and Central America is very similar to what is found on a Web site of tobacco history. The boldfaced words in this passage from the book echo language on the Web site: “In South and Central America the Indians smoked tobacco in pipes of many shapes and sizes, often elaborately decorated. It was sometimes chewed or used as snuff to ‘clear the head.’ Tobacco was also used as a remedy for such varied conditions as asthma, bites and stings, urinary and bowel complaints, fevers, convulsions, nervous ailments, sore eyes, and skin diseases. Some tribes cultivate tobacco as an insecticide to protect themselves against parasites.”

There’s also the possibility that Goodall, like Jonah Lehrer, made up quotations. As the Post reports:

“Seeds of Hope” tells the tale of botanists at the Royal Botanic Gardens, Kew, in London germinating 200-year-old seeds preserved in the Millennium Seed Bank. The seeds were shipped from Cape Town, were seized by the British and spent time in the Tower of London before winding up at the bank. Goodall concludes the story with a comment she says botanist Matt Daws made to her: “If seeds can survive that long in such poor conditions, then that’s good news for the ones that are stored under ideal conditions in the Millennium Seed Bank,’ Matt Daws said to me.”

Virtually the same quote from Daws appears on the Gardens Web site in a 2009 article with the headline “Plant story — 200 year old seeds spring to life”: “If seed can survive that long in poor conditions, then that’s good news for those in the Millennium Seed Bank stored under ideal conditions.” Asked in an e-mail whether he ever had a conversation with Goodall, Daws replied: “To be perfectly honest I have no recollection of speaking to her.”

An analysis of Goodall’s book by Michael Moynihan in The Daily Beast suggests there are many other plagiarized passages not uncovered by the Post, as well as another partially fabricated quote:

  • In my quick look through Seeds of Hope, I found what appears to be a similar example of plagiarism. Dave Aplin, a British botanist, is quoted telling Goodall of his discovery of seeds belonging to a long-extinct plant: “‘During my research,’ he told me, ‘I discovered a handful of preserved seeds hidden deep in the vaults of our seed bank.’ He felt a sense of awe.’ It was clear that I was probably looking at the last few seeds of this species in existence,’ he said.”

    But here is Dave Aplin quoted in a 2005 article from BBC News: “It was clear that I was probably looking at the last few seeds of this species in existence, and so some of the seeds were also dispatched to Britain so that both institutes could try to germinate them.” An added sentence—possibly from an actual interview Goodall conducted with Aplin—followed by a pilfered (and truncated) one.

Remember that Jonah Lehrer was fired from The New Yorker and disgraced for similarly fabricating quotes.

  • A quick check of other passages, randomly selected, suggest that there are many more instances of plagiarism that went undiscovered by the Post. Describing a study of genetically modified corn, Goodall writes: “A Cornell University study showed adverse effects of transgenic pollen (from Bt corn) on monarch butterflies: their caterpillars reared on milkweed leaves dusted with Bt corn pollen ate less, grew more slowly, and suffered higher mortality.”

A report from Navdaya.org puts it this way: “A 1999 Nature study showed adverse effects of transgenic pollen (from Bt corn) on monarch butterflies: butterflies reared on milkweed leaves dusted with bt corn pollen ate less, grew more slowly, and suffered higher mortality.”

The list of “unintentional borrowings” goes on, but you get the idea. Also disturbing are the many errors that Moynihan found, including attributing Confessions of an English Opium Eater to Samuel Taylor Coleridge instead of Thomas de Quincey.

That’s a small one, but there are several others. More serious is Goodall’s apparent dislike of GMO crops—which appear to be perfectly safe—and her citing of several dubious studies that appear to show their dangers (she cites, for instance, a CDC study as apparently showing that GM corn causes allergic reactions, but the CDC itself concluded that there was no effect).

As Moynihan notes, perhaps some of these errors and scientific distortions can be attributed to Goodall’s co-author, but that hardly applies to quotes from interviews supposedly conducted by Goodall—quotes that either were not uttered (since Goodall may not have spoken to the person indicated) or were partially fabricated. At any rate, Goodall is the book’s first author, and is responsible for the contents.

How bad is all this? Given the combination of distorted presentation of scientific studies, fabricated quotes, and plagiarism—and yes, by any standards it’s plagiarism—it looks pretty bad. In fact, if the book had been by a less revered person I suspect it would have been withdrawn from publication, as were two of Jonah Lehrer’s books that contained fabricated quotes or other unattributed material. Seeds of Hope was scheduled for release on April 2, but this has apparently been postponed indefinitely while the publisher, Hachette, allows Goodall to “correct any unintentional errors.”

“Unintentional errors” is the same excuse I’ve gotten in the past from students who copied material, but those students were still disciplined for plagiarism.

This is all very sad, and the scandal will surely dog Goodall as she treks around the world giving talks. It’s almost surely sloppiness and not cheating, but if we can’t trust Jane Goodall to report things accurately, who can we trust?

E. O. Wilson mistakenly touts group selection (again) as a key factor in human evolution

February 26, 2013 • 9:43 am

As most of you know, Edward O. Wilson is one of the world’s most famous and accomplished biologists.  He was the founder of evolutionary psychology (known as “sociobiology” back then), author of two Pulitzer-Prize-winning books, one of the world’s great experts on ants, an ardent advocate for biological conservation, and a great natural historian. His legacy in the field is secure.

So it’s sad to see him, at the end of his career, repeatedly flogging a discredited theory (“group selection”: evolution via the differential propagation and extinction of groups rather than genes or individuals) as the most important process of evolutionary change in humans and other social species. Let me back up: group selection is not “discredited,” exactly; rather, it’s not thought to be an important force in evolution.  There’s very little evidence that any trait (in fact, I can’t think of one, including cooperation) has evolved via the differential proliferation of groups.

In contrast, there is a ton of evidence for an alternative explanation for cooperation: kin selection, the selection of genes based on how they affect not just the fitness of the individual, but the fitness of relatives that share its genes.  Features like parental behavior, parent-offspring conflict, sibling rivalry, and preferential dispensing of favor to relatives, as well as features like sex ratios in insects—all of these are all easily explained by kin selection.  And many aspects of cooperation can easily be explained by individual selection: individuals that live in small groups, especially those in which one can recognize group members, can evolve cooperation as an individual good based on reciprocity: the “I scratch your back, you scratch mine” hypothesis.  And, as I’ve discussed before, the cooperative and “altruistic” behavior seen in our own species shows many features suggesting that it evolved via individual or kin selection and not group selection.

I’ve covered this issue many times (e.g., here, here, here, here, and here), so I won’t go over the arguments again. Wilson’s “theory” that group selection is more important than kin selection in the evolution of social behavior (published in Nature with Martin Nowak and Corina Tarnita) was criticized strongly by 156 scientists—including virtually every luminary in social evolution—in five letters to the editor, and sentiment about the importance of group selection has, if anything, decreased since Wilson’s been pushing it.

But Wilson persists, to the detriment of his reputation. In a new piece at the New York Times “Opinionator” site, “The riddle of the human species,” Wilson continues to make the same argument that group (or “multilevel”) selection was a key force in making humans (and social insects) the socially complicated species they are.  Since his arguments are virtually identical to those published in a NYT Opinionator piece last June, and in his book The Social Conquest of Earth (see part of my review here), I won’t dissect them in detail. I just want to highlight three points that I think make Wilson’s argument for group selection—and against kin selection—deeply misleading. I wouldn’t spend my time writing time-consuming critiques like this were Wilson not famous, influential, and given a big public forum in the New York Times. Someone has to address his arguments!

Here are Wilson’s errors (quotes indented), and my responses:

1. Wilson: Humans are a “eusocial species”:

. . the known eusocial species arose very late in the history of life. It appears to have occurred not at all during the great Paleozoic diversification of insects, 350 to 250 million years before the present, during which the variety of insects approached that of today. Nor is there as yet any evidence of eusocial species during the Mesozoic Era until the appearance of the earliest termites and ants between 200 and 150 million years ago. Humans at the Homo level appeared only very recently, following tens of millions of years of evolution among the primates.

My response:  “Eusociality” as defined by Wilson and every other evolutionist is the condition in which a species has a reproductive and social division of labor: eusocial species have “castes” that do different tasks, with a special reproductive caste (“queens”) that do all the progeny producing, and “worker castes” that are genetically sterile and do the tending of the colony. Such species include Hymenoptera (ants, wasps and bees, though not all species are eusocial), termites, naked mole rats, and some other insects.

But humans don’t have reproductive castes, nor genetically determined worker castes.  Wilson is going against biological terminology, lumping humans with ants as “eusocial,” so he can apply his own theories of “altruism” in social insects (i.e., workers “unselfishly” help their mothers produce offspring while refraining themselves from reproducing), to humans. But human cooperation and altruism are very different from the behavior of ants, most notably in our absence of genetic castes and genetically-based sterility associated with helping others reproduce. Human females aren’t sterile, and don’t usually refrain from reproduction just to help other women have babies.  My guess is that Wilson lumps humans with insects as “eusocial” because he wants to subsume them both under a Grand Theory of Social Evolution.

2. Wilson: Kin selection doesn’t work, ergo it certainly couldn’t have played a role in the evolution of eusociality and human cooperation.

Still, to recognize the rare coming together of cooperating primates is not enough to account for the full potential of modern humans that brain capacity provides. Evolutionary biologists have searched for the grandmaster of advanced social evolution, the combination of forces and environmental circumstances that bestowed greater longevity and more successful reproduction on the possession of high social intelligence. At present there are two competing theories of the principal force. The first is kin selection: individuals favor collateral kin (relatives other than offspring) making it easier for altruism to evolve among members of the same group. Altruism in turn engenders complex social organization, and, in the one case that involves big mammals, human-level intelligence.

The second, more recently argued theory (full disclosure: I am one of the modern version’s authors), the grandmaster is multilevel selection. This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Multilevel selection is gaining in favor among evolutionary biologists because of a recent mathematical proof that kin selection can arise only under special conditions that demonstrably do not exist, and the better fit of multilevel selection to all of the two dozen known animal cases of eusocial evolution.

My response:  There is so much fail here I don’t know where to start.  The first paragraph is basically correct except that Wilson omits “individual selection” along with “kin selection” as an accepted evolutionary process that can promote the evolution of cooperation. As I mentioned, selection on individuals in small groups can allow the evolution of cooperation without any need to invoke the unparsimonious process of differential group survival based on genes.

Wilson’s claim that the “special conditions of kin selection” demonstrably do not exist is an egregious and (I think) willful misstatement.  Kin selection can cause evolution whenever the genes in an individual benefit relatives that share copies of that individual’s genes, and can do so whenever the benefit of that behavior to the recipients, devalued by their degree of relatedness to the donor (a figure usually ranging between 0 and 1, but which can be related if an individual helps another less related to it than the average member of the population) is greater than the reproductive cost to the donor.  (“Hamilton’s rule”: rb > c.) That is known to obtain in many cases, and explains things like parental care, parent-offspring conflict, sex ratios in insects, and many other features (see the five letters in Nature mentioned above, which list some features of social behavior that clearly evolved by kin rather than group selection).

The mathematical “proof” given by Nowak et al. does not show that group selection is a better explanation than kin selection for social behavior in insects, for their “proof” does not vary the level of kinship, as it must if it could allow that conclusion.

The second egregious and false claim in this paragraph (a paragraph that’s the highlight of the piece) is that “multilevel selection is gaining in favor among evolutionary biologists” because of the Nowak et al. paper. That’s simply not true.  The form of multilevel selection adumbrated in that paper is, to my knowledge, embraced by exactly four people: the three authors of the paper and David Sloan Wilson. There is, and has been, no increase in acceptance of group or multilevel selection in the past ten years. The Nowak et al. paper has sunk without a stone, except to incite criticism by other biologists and excitement by an uncomprehending press.

3. Wilson: Eusociality in insects arose not via kin selection, but via the initial construction of a defended nest site.

The history of eusociality raises a question: given the enormous advantage it confers, why was this advanced form of social behavior so rare and long delayed? The answer appears to be the special sequence of preliminary evolutionary changes that must occur before the final step to eusociality can be taken. In all of the eusocial species analyzed to date, the final step before eusociality is the construction of a protected nest, from which foraging trips begin and within which the young are raised to maturity. The original nest builders can be a lone female, a mated pair, or a small and weakly organized group. When this final preliminary step is attained, all that is needed to create a eusocial colony is for the parents and offspring to stay at the nest and cooperate in raising additional generations of young. Such primitive assemblages then divide easily into risk-prone foragers and risk-averse parents and nurses.

My response:  Phylogenetic studies show that eusociality in Hymenoptera always originated in species whose females mated only once: this is a statistically significant result.  And that alone militates for kin selection as an important factor in eusociality: if a female founds a colony consisting only of full siblings (as is the case when she mated only once), they are more related to each other than if she had mated multiply. In the later case, colonies would consist of half-sisters or even more distant relatives, making kin selection less efficient.

Further, relatedness is high in virtually every species of eusocial insect with the exception of a few highly derived species of ants that have many queens.  The connection between relatedness and eusociality is exactly what we expect if kin selection is important in social evolution, and is not expected if Wilson’s nest-based group selection was important. The model of Nowak et al., which starts with the construction of such nests by single females who stay in the nests with their offspring, produces precisely the condition in which relatedness can promote the evolution of sterility and cooperation.  They argue that this relatedness is a consequence of their model and not a cause of eusocial evolution, but that’s unconvincing, for they do not vary the level of initial relatedness in their model.

*****

Wilson’s claim, the theme of his newest book, is that humans are both angels and devils: we are both selfish and cooperative species, and this combination of good and bad is what makes our species unique. (That’s not true, of course, because many species show that mixture of behavior. Lions, for instance, cooperate when hunting, but when males take over a pride they immediately kill all the female’s cubs, which are unrelated to them. And that, by the way, is due to kin selection, because those cub-killing males replace the cubs with new cubs containing their own genes, including the genes for killing cubs. Cub-killing could have evolved only by individual selection and not group selection, for while killing another male’s cubs is good for an individual, it’s bad for the group, forcing females to waste reproductive energy.)

Yes, we have both selfish and cooperative behaviors, though most of our “cooperative” behaviors that didn’t arise through culture arose through forms of selection that involve maximizing our reproductive output—individual and kin selection.  There is not a scintilla of evidence, in humans or any other species, that group selection has been responsible for the evolution of any adaptation.  In contrast, individual and kin selection have productively explained the evolution of “problematic” traits like altruism and cooperation. They have been tested and work.

Why does Wilson keep writing article and article, and book after book, promoting group selection? I’m not a psychologist, so I don’t know the answer. What I do know, though, is that his seeming monomaniacal concentration on a weakly-supported form of evolution can serve only to erode his reputation.  His theories have not gained traction in the scientific community. That doesn’t mean that they’re wrong, for, in the end, scientific truth is decided by experiment and observation, not by the numbers of people initially on each side of an issue. But the facts of science already show that Wilson is unlikely to be correct. What is sad is that, as a great natural historian, he doesn’t recognize this.

Wilson’s reputation is secure. It’s sad to see it tarnished by ill-founded arguments for an unsubstantiated evolutionary process.

h/t: Phil Ward, Laurence Hurst

The Piltdown Hoax at 100

December 18, 2012 • 12:16 pm

by Greg Mayer

The Geological Society (London) is having a special meeting today to commemorate the 100th anniversary of the Piltdown  hoax. There will also be a tour of a new special exhibit at the Natural History Museum (which also has a nice Piltdown website). It was exactly 100 years ago today that Charles Dawson, a Sussex antiquarian, along with Arthur Smith Woodward and Grafton Elliott Smith, both accomplished biologists, announced the discovery of the remains of a heretofore unknown hominid in a gravel pit in Piltdown, East Sussex.

Piltdown skull
A reconstruction of the Piltdown skull. Bone dark, reconstructed elements in white. Note that the skull consisted of parts of the braincase, nasals, and a right mandible, with no connections between the parts. Note also that the mandible is missing the anterior teeth.

Dawson claimed that the right mandible (broken anteriorly) and the braincase pieces had been recovered from the gravel pit. It appeared to show that in the Pleistocene of Britain there occurred a large-brained but ape-jawed ancestor of man. Many of Britain’s most prominent paleontologists, anatomists, and zoologists concurred with this analysis.

Piltdown gang
The “Piltdown gang”. Standing: F.O. Barlow, Grafton Elliot Smith, Charles Dawson, Arthur Smith Woodward. Seated: A.S. Underwood, Arthur Keith, W.P. Pycraft, and Sir E. Ray Lankester.

From the start, however, there was controversy as to whether the man-like cranium and ape-like jaw were from the same species. The fact that the intervening parts of the skull were missing made it impossible to demonstrate the case morphologically. Regardless, the general conclusion was to accept the association of the jaw and cranium. When Australopithecus was discovered in Africa by Raymond Dart in the 20’s, the significance of his find was underestimated since the African form had a man-like jaw and an ape-like cranium– the opposite of Piltdown. As further discoveries showed that Piltdown man was aberrant, it came to figure less prominently in accounts of human evolution.

Beginning in the late 1940’s a series of investigations were begun that explained the source of the anomaly– the Piltdown remains were not only not associated, they were relatively recent, had been stained to look old, and filed down to change their appearance– they were a deliberate forgery!  In 1953, J.S. Weiner, K.P. Oakley, and W. Le Gros Clark published their results in a Natural History Museum monograph (reference below), and, appropriately, presented their results a few days later at a meeting of the Geological Society. A longer monograph appeared two years later.

Exposure of Piltdown hoax
Meeting of the Geological Society on 25 November, 1953, at which K.P. Oakley presented evidence for the fraudulent nature of the Piltdown specimens (Daily Mail; the Mail only identifies the photo as of the meeting at which the hoax was exposed; The Times for 26 November 1953 gives the further details of the meeting).

There had, in fact, long been doubts about the provenance of the Piltdown specimens. In 1914, W.K. Gregory (1914: 190-191) expressed it pretty directly:

It has been suspected by some that geologically they are not old at all; that they may even represent a deliberate hoax, a negro or Australian skull and a broken ape-jaw, artificially fossilized and “planted” in the gravel-bed, to fool the scientists. Against this suggestion tell the whole circumstances of the discovery as above related.

At the time, Gregory accepted the story of discovery. The following year, G.S. Miller strongly stated that the specimens were not associated, declaring unequivocally that the jaw was simian, the cranium human. More elliptically, he wrote (1915: 1):

Deliberate malice could hardly have been more successful than the hazards of deposition in so breaking the fossils as to give free scope to individual judgment in fitting the parts together.

Colin Groves was told that Miller actually thought it was a hoax, but that decorum prevented him from saying so without proof, and so he contested the find on scientific grounds; it would be interesting to see what is written in Miller’s papers about the matter (perhaps someone has already looked). Another American zoologist, W.D. Matthew, readily accepted Miller’s conclusions (Matthew in Eastman et al., 1916: 107):

In the present reviewer’s opinion [W. D. M.] Dr. Miller’s argument is convincing and irrefutable; the jaw belonged to a chimpanzee and the skull to a species of man comparable with that represented by the Heidelberg jaw. It is hardly to be expected, however, that this conclusion will be readily accepted by the European writers, who have with but few exceptions committed themselves more or less deeply to the opposite view.

And, changing his previous view, so did Gregory (1916: 313):

In an earlier paper (1914) I have reviewed the controversy over the Piltdown remains (Eoanthropus dawsoni), emphasizing the entirely human character of the brain-case, the essentially ape-like character of the lower jaw and teeth and the doubts as to their association already expressed by several authors.

While I take no delight in the predicament of those taken in by the hoax, I do delight in the fact that Miller, Gregory, and Matthew were among those to see the true nature of the material: I have had occasion to refer and use their work in my own researches and teaching, and Gregory is one of my academic grandfathers.

After the exposure of the hoax, the incident became chiefly of historical rather than scientific interest, and the question of who perpetrated the hoax has been of recurring interest. Suspicion first fell on Dawson, but has included Smith Woodward, Arthur Keith, Teilhard de Chardin, and even Arthur Conan Doyle!  Miles Russell of Bournemouth University has discovered that Dawson was involved in a number of frauds and fakeries, and an extensive summary of his case against Dawson is online. He is speaking today at the Geological Society, and has just published a new book on the subject (reference below).

In addition to the new exhibit and the conference, Chris Stringer of the Natural History Museum is leading a team that will conduct further tests on the bones that they hope will allow them to produce more definitive evidence of who was involved in perpetrating the hoax. Both the conference and the further testing have drawn considerable media interest in the UK (Guardian, Telegraph, BBC, Daily Mail). Further online information on the Piltdown story can be found at the late Richard Harter’s website, a Clark University site with transcripts of many original papers, and at the Talk Origins archive.

h/t Sigmund

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Dawson, C., A. Smith Woodward, and G.E. Smith. 1913. On the discovery of a palæolithic human skull and mandible in flint-bearing gravel overlying the Wealden (Hastings Beds) at Piltdown, Fletching (Sussex). Quarterly Journal of the Geological Society 69:117-147. (transcription)

Eastman, C.R., W.K. Gregory, and W.D. Matthew. 1916. Recent progress in vertebrate paleontology. Science New Series 43:103-110.

Gregory, W. K. 1914. The Dawn Man of Piltdown, England. American Museum Journal 14:189-200. (pdf)

Gregory, W.K. 1916. Studies on the evolution of the Primates. Bulletin of the American Museum of Natural History 35:239-355. (pdf)

Matthew, W.D. 1916. Note on the association of the Piltdown skull and jaw. Bulletin of the American Museum of Natural History 35:348-350. (in Gregory, 1916)

Miller, G.S. 1915. The Jaw of the Piltdown Man. Smithsonian Miscellaneous Collections 65(12):1-31. (Biodiversity Heritage Library)

Russell, M. 2003. Piltdown Man: The Secret Life of Charles Dawson. Tempus Books, Stroud, UK. (Amazon)

Russell, M. 2012. The Piltdown Man Hoax: Case Closed. History Press, Stroud, UK. (publisher)

Weiner, J.S., K.P. Oakley, and W.E. Le Gros Clark. 1953. The solution of the Piltdown problem. Bulletin of the British Museum (Natural History) Geology 2:139-146. (Biodiversity Heritage Library)

Creationist #3: One error after another

September 28, 2012 • 8:01 am

In the last ten days or so I’ve featured posts by two creationists trying to promulgate their misguided biology on my site. This is the last one, who goes by the name “Synapticcohesion.” As always, I’m proffering this for educational and sociological reasons: to display the mindset and tactics of those who reject modern biology in favor of a two-thousand-year-old manual for goatherds.

In response to my post “Evolution has a victory in South Korea,” this third commenter (whom I’ll call “Synaptic”) engaged in an exchange with me on the thread.  My comments are flush left, and Synaptic’s are indented. Italicized and indented words represent Synpaptic quoting from someone else—either me or another commenter:

Synaptic: “If you don’t have evidence, well then, stfu.”

YOU have no proof that, as mentioned on the comic, that we descended from apes. Only faulty conjecture. So take your own advice.

JAC: Okay, synaptic, before you can post again, explain why the mountains of evidence that we descended from a common ancestor with that of modern chimps, gorillas, etc. is WRONG. We’re waiting. .

Synaptic: I knew it would come to censorship. I wouldn’t be surprised if you don’t post my response so that the creationist appears to be at a “loss for words.”

You know very well that even if there were ancient remains of chimps/hominids (that were not a mix-and-match set of scant bones and bone fragments that they are) that appeared to have physical features that are not exactly like chimps today and aren’t like humans today–that is proof of NOTHING in terms of human evolution, that is simply proof that there are extinct primates (with varying physical features) that do not exist today. That does not prove “human ancestry” whatsoever. Nor do the extremely old, arthritic remains of Neanderthals–with their jutting, arthritic facial features–prove that they are our less evolved, more “apelike” ancestors.

This is the evolutionist’s ultimate failure–to be able to prove that their claims of “intermediaries” are anything more than wild conjecture.

JAC: Man, you either know nothing about the human fossil record or are blinkered by faith. Do you care to tell us why australopithecines, which have a humanlike postcranial skeleton but a skull with a 400-500 cc brain (the size of a chimp) are “arthritic”?

Did all Neanderthals have arthritis? And what about H. erectus, A. afarensis, and the like, which show temporal changes from early apelike forms about 4 mya to more “modern” ones 1.5 myr ago, and so on? How do you explain those temporal changes?

You have a very strange idea of what constitutes “evidence.” The hypothesis is that early hominins would have mixtures of humanlike and early apelike features. This is exactly what we find. It’s all supported with radiometric dating, too.

Do you think that all paleoanthropologists who support human evolution have been cruelly deluded?

Or do you consider Genesis to be “evidence”?

Synaptic:[JAC: This comment is appearing for the first time here since I did not let it go through but preferred to put it above the fold].  “Do you care to tell us why australopithecines, which have a humanlike postcranial skeleton but a skull with a 400-500 cc brain (the size of a chimp) are “arthritic”?”

I never suggested that these chimps were arthritic. As I had mentioned, “humanlike” features do not prove ancestry. There are various animals today that have “humanlike” this or that (including fish that have teeth that are very “humanlike”). But even some claims of the “humanlike” features supposedly attributed to australopithecines is questionable at best. “Lucy,” for example, is nothing more than a mix-and-matching of bone fragments admittedly found in DIFFERENT LOCATIONS. And Lucy’s femur, which is crucial to being able to even make the conjecture of an apelike human ancestor was not even discovered in one piece! The tell-tale evidence of angulation (the supposed “bicondylar angle”) of the femur was conveniently absent as the femur was missing it’s knee joint! Another piece (supposedly belonging to Lucy) was added to complete Lucy’s incomplete femur. How this small piece was able to be preserved separately (yet just as perfectly) in order to complete Lucy’s femur in order to prove a bicondular angle is amazing and the chances of this happening is astronomical.

Did all Neanderthals have arthritis? Yes, the vast majority discovered were arthritic. Why? Because unlike today where people succumb to diseases well before “old age” and even some infants die of various diseases including SIDS, there is evidence that our ancient ancestors lived a lot longer than we did. Thus, most of the remains would be expected to be very old and arthritic as our ancient ancestors lived a lot longer in an old environment that is hypothesized to be much richer in oxygen (based on the evidence found in the analysis of fossilized amber).

“The hypothesis is that early hominins would have mixtures of humanlike and early apelike features.”

Yes, and that does not make it true. Just because some suggest that that’s what something HAS to mean, HAS to be interpreted–does not make it so. There are many ways to interpret the same evidence and science is not immune with conflicts in interpretation. Even the remains of the T. rex has been interpreted in various ways–the evidence was there, but that did not mean that scientists agreed on how the T Rex stood and walked. (The improbable posture was introduced to the public as “scientific fact,” only to be altered in the 1990′s.)

“Or do you consider Genesis to be “evidence”?”

No, I look at the scientific evidence independently. That doesn’t mean I fail to see that much of the evidence uncovered ends up supporting the Bible in many ways.

Indeed, a truly an objective assessment of the evidence that just happens to coincide with Genesis! It really made me LOL that Synaptic thinks that Neanderthals all had arthritis (even the young ones!), and that their contemporaries, “modern’ Homo sapiens, did not! It can’t be a matter of two distinct morphs of humans in one species, one with arthritis and one not, since we also know that Neanderthals were a group that was genetically distinct from modern H. sapiens.

And of course the remains of early hominins are not “mix and match” fragments of fossils: in many cases we have large pieces and nearly entire skulls. These, of course, shows a branching bush of evolution, with some hominins being robust, small-brained, and with big teeth, but others gradually approaching a human-like appearance with a larger skull, smaller teeth, and erect posture.

As for the Lucy story, I was pretty sure they found her as a single skeleton in one small, circumscribed area, and that the evidence for bipedality was convincing.  But just to be sure I wrote to anthropologist John Hawks (who has his own website) about Lucy. He was kind enough to respond:

The bicondylar or valgus angle is easy to judge on a distal femur. You do not need a complete bone, only around 10% of the bone’s length at the distal [far] end is really necessary. Chimpanzees and gorillas have femora where the distal articular surface is perpendicular to the shaft. Humans support our weight alternately on one leg at a time, so that our leg must angle from the hip joint to put a foot under the body’s center of gravity. We accomplish this entirely in the femur, which results in our distal articular surface being angled obliquely relative to the shaft.
In the Lucy skeleton itself, the distal femur is not as well preserved as in many other australopithecine specimens but is nevertheless sufficient to show the humanlike pattern. This is one of the clearest traits reflecting a bipedal locomotor pattern, present in many specimens of A. afarensis, A. robustus and A. africanus, and of course all members of the genus Homo.
I then wrote John back to clarify one point:

Thanks–I appreciate this.

I presume the following statement is wrong, too?

“‘Lucy,’ for example, is nothing more than a mix-and-matching of bone fragments admittedly found in DIFFERENT LOCATIONS.”

And he responded:

Yes, Lucy’s skeleton was all found at one locality, and has no duplicated bones. It is highly unlikely that the skeleton includes any elements from other individuals.

So there you have it: Synaptic, like our other two creationists, was being misleading—probably deliberately so. I believe that he knows better, and is spouting creationist drivel. The thing is, though, that he sounds convincing to those who don’t know anything about Lucy. The lesson (not needed by anyone here) is that if you hear “scientific” evidence adduced by a creationist, be sure to check it out.

Synaptic never did respond to my question of whether he saw all paleoanthropologists as engaged in a monstrous and pervasive conspiracy: trying to deceive people into thinking that scattered bone fragments, and skeletons of modern humans that were unhappily arthritic, represent real fossil evidence of our descent from a common ancestor with modern apes. I guess the creationists have found us out!

Below is the skeleton of Lucy (A. afarensis, dated 3.2 mya), from Wikipedia. She had a “primitive” skull of low volume, a semi-parabolic jaw intermediate in shape between that of modern apes (rectangular) and modern humans (fully parabolic), and the skeleton below the neck is very “modern” and bipedal. Contrary to Synaptic, all these fragments come, to our best knowledge, from a single individual (there were no duplicated pieces in the same area, and it was found in a small area).

Do read the “Lucy” entry; it’s short.  Here she is (the femur is the long leg bone):

Ancient sacrificed children studied for infection

July 28, 2012 • 5:24 am

In the past 500 years, humanity has come a long distance in the way we treat children, women, animals, those of other faiths, and members of other cultures; see Steve Pinker’s superb new book, The Better Angels of Our Nature, for the documentation.  A graphic example of this progress comes from a new paper in PLoS ONE by Angelique Corthals et al. (free download). It’s about infections in children ritually sacrificed by the Incas.

In 1999, a group of archaeologists discovered the preserved bodies of three children near the summit of a high volcano in Argentina.  Dating back about five centuries, they included a 6-year old girl, a 7-year old boy, and a 15-year old girl.  All of them had been sacrificed to the gods by the horrible practice of capacocha, as described by Wikipedia:

Capacocha was the Inca practice of human sacrifice, mainly using children. The Incas performed child sacrifices during or after important events, such as the death of the Sapa Inca (emperor) or during a famine. Children were selected as sacrificial victims as they were considered to be the purest of beings. These children were also physically perfect and healthy, because they were the best the people could present to their gods. The victims may be as young as 6 and as old as 15.

Months or even years before the sacrifice pilgrimage, the children were fattened up. Their diets were those of the elite, consisting of maize and animal proteins. They dressed the children in fine clothing and jewelry and escorted them to Cuzco to meet the emperor where a feast was held in their honor. More than 100 precious ornaments were found to be buried with these children in the burial site.

The Incan high priests took the victims to high mountaintops for sacrifice. As the journey was extremely long and arduous, especially so for the younger victims, coca leaves were fed to them to aid them in their breathing so as to allow them to reach the burial site alive. Upon reaching the burial site, the children were given an intoxicating drink to minimize pain, fear, and resistance, then killed them either by strangulation, a blow to their head or by leaving them to lose consciousness in the extreme cold and die of exposure.

The bodies had been exceptionally well preserved over five centuries because they were buried 20 cm underground in freezing temperatures, and the tombs packed with volcanic ash and covered with compacted snow.

Here are three photos taken from the paper; the caption is “a) La Doncella (the Maiden); b) El Niño (the Boy); and c) La Niña (the Girl)”.  The Maiden was the 15-year old, and the one studied for infection. Her hair is finely braided. You’ll find these pictures ineffably moving; they look just like children from modern Peru:

Child sacrifice was not rare in pre-Columbian cultures. Here’s a description of an equally noxious practice of some Aztecs:

Archaeologists have found the remains of 42 children sacrificed to Tlaloc (and a few to Ehecátl Quetzalcóatl) in the offerings of the Great Pyramid of Tenochtitlan. In every case, the 42 children, mostly males aged around six, were suffering from serious cavities, abscesses or bone infections that would have been painful enough to make them cry continually. Tlaloc required the tears of the young so their tears would wet the earth. As a result, if children did not cry, the priests would sometimes tear off the children’s nails before the ritual sacrifice.

At any rate, the PLoS One paper involved an analysis of blood samples and mouth swabs of the mummies using “proteomics,” the practice of isolating proteins from body fluids and identifying them by mass spectrometry. I won’t describe the complicated procedure, which you can read about here, but the aim was to see whether the children carried infections (the youngest girl wasn’t sampled as her body had apparently been struck by lightning).  There were preliminary signs that the older girl was indeed ill; as the paper notes:

Computed tomography (CT) scanning and radiological examinations of the Maiden revealed that all her organs, including the eyes and the brain, were intact. Both radiological and visual examination revealed pathologies consistent with a range of infectious diseases: 1) a radiolucent area in the upper lobe of the right lung, 2) a mucosal enlargement of the left maxillary sinus consistent with sinusitis, 3) a zoster-like lesion on the right calf, and 4) streaks of mucus under both nostrils.

The proteomic analysis showed several proteins in the Maiden (but not the boy) consistent with infection: proteins produced by the body to fight off microbes.  Several of these indicated a pretty severe inflammation of the lungs, presumably by mycobacteria.  This was confirmed by finding proteins from the Mycobacterium itself. Since Mycobacterium tuberculosis is one of the causes of tuberculosis, it’s possible that, even at age 15, she’d already contracted TB.

The question here may seem narrow, but does have broader implications, particularly in investigating via proteomics what diseases afflicted ancient people.  Proteins can last a lot longer than DNA, and are less subject to contamination, so looking at the proteins of both pathogen and host (i.e., those proteins involved in the host’s immune response) can tell us about the health of our ancestors.  The authors also note that the technique can help identify the state of infection from analysis of blood in modern criminal cases, which I suppose can sometimes be useful.

But what stays with me after having read the paper are the photos of the children, needlessly slaughtered—as were so many adults—in the name of a nonexistent deity. Religion has poisoned everything for a long time.

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Corthals A, Koller A, Martin DW, Rieger R, Chen EI, et al. (2012) Detecting the Immune System Response of a 500 Year-Old Inca Mummy. PLoS ONE 7(7): e41244. doi:10.1371/journal.pone.0041244

The peopling of the Americas

July 12, 2012 • 9:55 am

by Greg Mayer

The Americas were the last continents to be inhabited, and there has long been controversy about how and when it occurred. There is a general consensus that the earliest Americans arrived from northeastern Asia in the late Quaternary, but the exact peoples involved, the routes taken, when they arrived, and the modes of travel are all much debated. A paper by David Reich and colleagues, in press in Nature, presents evidence on one aspect of the question– did the first inhabitants arrive in one, or in more waves of migration? It has always seemed probable that the Eskimos, culturally and linguistically distinct from the American Indians to the south, and occurring on both sides of Bering Strait, represent a distinct migration, but were the more southern peoples the result of one, two, or more migrations?

Note that Na-Dene (green) and Eskimo-Aleut (red) derive in part from an Asian (black; Yoruba are African) ancestry separate from that of Amerind or First American (blue). (The Na-Dene and Eskimo-Aleut are not a single arrival from Asia; the Han Chinese are too genetically distant from east Siberian peoples to capture the ancestral source in this comparison.). D Reich et al. Nature, in press, doi:10.1038/nature11258

Here’s the money quote from Reich et al.’s abstract:

[W]e assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call ‘First American’. However, speakers of Eskimo–Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream.

The three migrations thus were by 1) a group the authors call First American, that gave rise to almost all of the Indians of North and South America; 2) the Na-Dene, a group also linguistically identified, that occurs in the US Southwest and a few other places in the US and Canada; and 3) the Eskimo-Aleut, who arrived most recently. These three groups had also been identified by the late linguist Joseph Greenberg (who called the first group “Amerind’).

This is actually pretty much the story as I understood it from the viewpoint of a biologist paying casual attention to the anthropological results. Media accounts (NY Times, BBC) make it sound a bit more novel and controversial than I would have thought. This could be due to my not fully grasping the state of the debates within anthropology (quite possible!), or the hyping that tends to accompany reporting of even the best scientific work.

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Reich, D. et al. 2012. Reconstructing Native American population history. Nature, in press.