Mismodeling Indo-European Origins: The Assault On Historical Linguistics


Reply to some self-important dork whining about this talk at Dienekes':

"You simply cannot criticize a new, rapidly-evolving and improving model just based on its trivial, known shortcomings. Such a thing is ludicrous and paints a truly bad picture of the talk presenters."

I'm afraid your effeminate idea of proper protocol has no bearing on actual science. Gray and Atkinson's "innovation" is insisting that Bayesian phylogenetics with limited and sometimes questionable inputs of data can produce highly accurate and precise readouts of linguistic history that supercede all previous linguistic and archaeological knowledge. Their results may dazzle twits like you and appeal to those who find their results politically or ethnically congenial. But the first question a serious person would ask is how closely Gray and Atkinson's attempts at reconstruction recapitulate recent/known linguistic history. That they frequently fail to do so is extremely germane to the question of how much faith one should put in their deeper reconstructions.

Statistical models are not magic. Bayesian tree building is not magic. Even with large corpuses of genetic data, the "most likely" tree is often overwhelmingly likely to be wrong. For genetics, where there's an explosion of data with comparatively few human analysts and little or no historical context, such results are useful, being often the best we have until additional data and further refinements of models appear. On the other hand, in linguistics, where on the PIE question relatively many human analysts have been poring over a comparatively limited corpus for many decades, it's up to Gray and Atkinson to demonstrate they have something useful to contribute. Every indication says they do not.

23andMe price drop

For those interested: "23andMe Raises More Than $50 Million in New Financing / Company Sets Growth Goal Of One Million Customers, Reduces Price to $99 from $299"

The GenoChip: A New Tool for Genetic Anthropology

Preprint at arXiv:
The Genographic Project is an international effort using genetic data to chart human migratory history. The project is non-profit and non-medical, and through its Legacy Fund supports locally led efforts to preserve indigenous and traditional cultures. In its second phase, the project is focusing on markers from across the entire genome to obtain a more complete understanding of human genetic variation. Although many commercial arrays exist for genome-wide SNP genotyping, they were designed for medical genetic studies and contain medically related markers that are not appropriate for global population genetic studies. GenoChip, the Genographic Project's new genotyping array, was designed to resolve these issues and enable higher-resolution research into outstanding questions in genetic anthropology. We developed novel methods to identify AIMs and genomic regions that may be enriched with alleles shared with ancestral hominins. Overall, we collected and ascertained AIMs from over 450 populations. Containing an unprecedented number of Y-chromosomal and mtDNA SNPs and over 130,000 SNPs from the autosomes and X-chromosome, the chip was carefully vetted to avoid inclusion of medically relevant markers. The GenoChip results were successfully validated. To demonstrate its capabilities, we compared the FST distributions of GenoChip SNPs to those of two commercial arrays for three continental populations. While all arrays yielded similarly shaped (inverse J) FST distributions, the GenoChip autosomal and X-chromosomal distributions had the highest mean FST, attesting to its ability to discern subpopulations. The GenoChip is a dedicated genotyping platform for genetic anthropology and promises to be the most powerful tool available for assessing population structure and migration history.
Let's be clear: the "most powerful tool available for assessing population structure and migration history" is whole genome sequencing. The Genographic Project, which represents a large fraction of the global spending on its type of population genetics research, unnecessarily hobbled itself from the outset in hopes of pre-emptively appeasing rent-seeking shrill self-appointed advocates for "indigenous peoples". I don't think Spencer Wells and company thought they were giving up much, since the short-sighted original plan was to examine only uniparental markers. In that light, perhaps we can be thankful that they've come up with a way of sidestepping the restrictions they placed on themselves and generating at least some useful autosomal data.
Several steps were taken to ensure that the genetic results would not be exploited for pharmaceutical, medical, and biotechnology purposes. First, participant samples were maintained in a completely anonymous status during GenoChip analysis. Second, no phenotypic or medical data were collected from the participants. Third, we included only SNPs in noncoding regions without any known functional association, as reported in dbSNP build 132. Lastly, we filtered our SNP collection against a 1.5 million SNP data set containing all variants that have potential, known, or suspected associations with diseases.
But however they'd like to spin it there's nothing ideal about ignoring "functional" variation or limiting the number of SNPs tested. Razib has a bizarre post up at his Discover blog in which he confuses SNP ascertainment and "Ancestry Informative Marker" ascertainment, and I see that the authors of the paper themselves appear to be eliding the distinction. But the overwhelming majority of the "450 populations" from which "AIMs" were "ascertained" for the GenoChip had merely been typed on existing microarrays -- which goes no ways towards addressing the issue the Affymetrix Human Origins array was designed to address (putting together SNP panels with known ascertainment, starting by sequencing individuals from multiple populations). Ultimately, the most useful and complete picture of human genetic history will come from whole genome sequencing, which should be cheap enough within a few years for use by the Genographic Project. The question is have they permanently handicapped themselves from applying the actual best tool for their stated mission, or will we eventually see at least some whole genome data for their 75,000 indigenous samples (no doubt with at minimum coding regions redacted).

Protective buttressing of the human fist and the evolution of hominin hands

FIGHTING SHAPED HUMAN HANDS. Protective buttressing of the human fist and the evolution of hominin hands
The derived proportions of the human hand may provide supportive buttressing that protects the hand from injury when striking with a fist. Flexion of digits 2–5 results in buttressing of the pads of the distal phalanges against the central palm and the palmar pads of the proximal phalanges. Additionally, adduction of the thenar eminence to abut the dorsal surface of the distal phalanges of digits 2 and 3 locks these digits into a solid configuration that may allow a transfer of energy through the thenar eminence to the wrist. To test the hypothesis of a performance advantage, we measured: (1) the forces and rate of change of acceleration (jerk) from maximum effort strikes of subjects striking with a fist and an open hand; (2) the static stiffness of the second metacarpo-phalangeal (MCP) joint in buttressed and unbuttressed fist postures; and (3) static force transfer from digits 2 and 3 to digit 1 also in buttressed and unbuttressed fist postures. We found that peak forces, force impulses and peak jerk did not differ between the closed fist and open palm strikes. However, the structure of the human fist provides buttressing that increases the stiffness of the second MCP joint by fourfold and, as a result of force transfer through the thenar eminence, more than doubles the ability of the proximal phalanges to transmit ‘punching’ force. Thus, the proportions of the human hand provide a performance advantage when striking with a fist. We propose that the derived proportions of hominin hands reflect, in part, sexual selection to improve fighting performance.
Human hands have 'evolved for fighting'
Compared with apes, humans have shorter palms and fingers and longer, stronger flexible thumbs.

Experts have long assumed these features evolved to help our ancestors make and use tools.

But new evidence from the US suggests it was not just dexterity that shaped the human hand, but violence also.

Hands largely evolved through natural selection to form a punching fist, it is claimed.

''The role aggression has played in our evolution has not been adequately appreciated,'' said Professor David Carrier, from the University of Utah.

''There are people who do not like this idea but it is clear that compared with other mammals, great apes are a relatively aggressive group with lots of fighting and violence, and that includes us. We're the poster children for violence.'' [. . .]

''Individuals who could strike with a clenched fish could hit harder without injuring themselves, so they were better able to fight for mates and thus be more likely to reproduce,'' he said. [. . .]

To test the theory Prof Carrier conducted experiments with volunteers aged 22 to 50 who had boxing or martial arts experience.

In one, participants were asked to hit a punchbag as hard as possible from different directions with their hands in a range of shapes, from open palms to closed fists.

The results, published in the Journal of Experimental Biology, show that tightly clenched fists are much more efficient weapons than open or loosely curled hands.

A punch delivers up for three times more force to the same amount of surface area as a slap. And the buttressing provided by a clenched fist increases the stiffness of the knuckles fourfold, while doubling the ability of the fingers to deliver a punching force. [. . .]

''Human-like hand proportions appear in the fossil record at the same time our ancestors started walking upright four million to five million years ago. An alternative possible explanation is that we stood up on two legs and evolved these hand proportions to beat each other.''

Manual dexterity could have evolved without the fingers and palms getting shorter, he said. But he added: ''There is only one way you can have a buttressed, clenched fist: the palms and fingers got shorter at the same time the thumb got longer.''

Prof Carrier cited other evidence pointing to the role of fighting in the evolution of human hands.

:: No ape other than humans hits with a clenched fist.

:: Humans use fists instinctively as threat displays. ''If you are angry, the reflexive response is to form a fist,'' said Prof Carrier. ''If you want to intimidate somebody, you wave your fist.''

:: Sexual dimorphism, or the difference in body size between the sexes, tends to be greater among primates when there is more competition between males. In humans the difference is mainly in the upper body and arms, especially the hands. ''It's consistent with the hand being a weapon,'' said Prof Carrier.

In their paper the professor and colleague Michael Morgan, a University of Utah medical student, ponder on the paradoxical nature of the human hand.

''It is arguably our most important anatomical weapon, used to threaten, beat and sometimes kill to resolve conflict. Yet it is also the part of our musculoskeletal system that crafts and uses delicate tools, plays musical instruments, produces art, conveys complex intentions and emotions, and nurtures,'' they write.

''More than any other part of our anatomy, the hand represents the identity of Homo sapiens. Ultimately, the evolutionary significance of the human hand may lie in its remarkable ability to serve two seemingly incompatible but intrinsically human functions.''

War of words: The language paradox explained

New Scientist article (free copy) by Mark Pagel (via Jason Malloy's bookmarks). Some mostly worthwhile paragraphs precede the requisite pollyannaish-on-globalism denouement.
This highlights an intriguing paradox at the heart of human communication. If language evolved to allow us to exchange information, how come most people cannot understand what most other people are saying? This perennial question was famously addressed in the Old Testament story of the Tower of Babel, which tells of how humans developed the conceit that they could use their shared language to cooperate in the building of a tower that would take them to heaven. God, angered at this attempt to usurp his power, destroyed the tower and to ensure it would not be rebuilt he scattered the people and confused them by giving them different languages. The myth leads to the amusing irony that our separate languages exist to prevent us from communicating. The surprise is that this might not be far from the truth. [. . .]

Of course that still leaves the question of why people would want to form into so many distinct groups. For the myriad biological species in the tropics, there are advantages to being different because it allows each to adapt to its own ecological niche. But humans all occupy the same niche, and splitting into distinct cultural and linguistic groups actually brings disadvantages, such as slowing the movement of ideas, technologies and people. It also makes societies more vulnerable to risks and plain bad luck. So why not have one large group with a shared language?

An answer to this question is emerging with the realisation that human history has been characterised by continual battles. Ever since our ancestors walked out of Africa, beginning around 60,000 years ago, people have been in conflict over territory and resources. In my book Wired for Culture (Norton/Penguin, 2012) I describe how, as a consequence, we have acquired a suite of traits that help our own particular group to outcompete the others. Two traits that stand out are "groupishness" - affiliating with people with whom you share a distinct identity - and xenophobia, demonising those outside your group and holding parochial views towards them. In this context, languages act as powerful social anchors of our tribal identity. How we speak is a continual auditory reminder of who we are and, equally as important, who we are not. Anyone who can speak your particular dialect is a walking, talking advertisement for the values and cultural history you share. What's more, where different groups live in close proximity, distinct languages are an effective way to prevent eavesdropping or the loss of important information to a competitor.

In support of this idea, I have found anthropological accounts of tribes deciding to change their language, with immediate effect, for no other reason than to distinguish themselves from neighbouring groups. For example, a group of Selepet speakers in Papua New Guinea changed its word for "no" from bia to bune to be distinct from other Selepet speakers in a nearby village. Another group reversed all its masculine and feminine nouns - the word for he became she, man became woman, mother became father, and so on. One can only sympathise with anyone who had been away hunting for a few days when the changes occurred.

The use of language as identity is not confined to Papua New Guinea. People everywhere use language to monitor who is a member of their "tribe". We have an acute, and sometimes obsessive, awareness of how those around us speak, and we continually adapt language to mark out our particular group from others. In a striking parallel to the Selepet examples, many of the peculiar spellings that differentiate American English from British - such as the tendency to drop the "u" in words like colour - arose almost overnight when Noah Webster produced the first American Dictionary of the English Language at the start of the 19th century. He insisted that: "As an independent nation, our honor [sic] requires us to have a system of our own, in language as well as government."