The unbearable thinness of Denisovan

A new paper in PNAS, Archaic human ancestry in East Asia: “These results suggest admixture between Denisovans or a Denisova-related population and the ancestors of East Asians, and that the history of anatomically modern and archaic humans might be more complex than previously proposed.” It’s open access, so do go read it. John Hawks has a long rumination. My main thought is that I’m starting to think that people are squeezing this orange too much. I wouldn’t be surprised if the broad conclusions here are correct, and in fact I’d lean in that direction. But is the discovery of relatively trace ancestry all that earthshaking? The reality is that a little over a year ago the interpretative framework of science in this area shifted. That was because of the concreteness of ancient DNA, which allowed for a direct comparison, instead of statistical sifting through the genomes of extant populations. Remember, before 2010 there were plenty of papers utilizing subtle statistics and computational muscle which “proved” and “confirmed” an Out-of-Africa with replacement model. The power and precision of these techniques tended to overshadow the reality of a margin of error, and uncertainty in their conclusions. We need to be cautious when the machinery turns itself in the opposite direction, gleaning glimpses of what we now know is likely there….

Sunday Stuff – October 30th, 2011


Something different today. First, an elegant international cat:

Second, reading prompts me to repost a very long essay I wrote ~3 years ago. I have some new ideas in the area of the evolution of religious institutions, which I want to work out in a new essay. But that’s going to have to occur when I have a long period of time to focus on something like that, and that I do not have currently.

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When genetics comes in handy in politics

In Mother Jones Andrew Serwer has a long profile up of a Mitt Romney adviser who has associations with Lebanese Christian sectarian radicals. This section jumped out at me:

Régina Sneifer, who served in the Fifth Bureau in 1981 at the age of 18, remembers attending lectures where Phares told Christian militiamen that they were the vanguard of a war between the West and Islam. She says Phares believed that the civil war was the latest in a series of civilizational conflicts between Muslims and Christians. It was his view that because Christians were eternally the victims of Muslim persecution, the only solution was to create a national home for Christians in Lebanon modeled after Israel. Like many Maronites at that time, Phares believed that Lebanese Christians were ethnically distinct from Arabs. (This has since proven to be without scientific basis.)

The scientific issue is actually a little more complex than Serwer comprehends. It is true that Muslims and non-Muslims in any given region share a lot genetically, but non-Muslim minorities in the Middle East have gone through a long period of endogamy and demographic contraction, resulting in genetic differences (mostly obviously, they seem to have less Sub-Saharan African admixture than their Muslim neighbors). But the interesting point is how widespread genetic information is now becoming in trying to understand various issues. Serwer is broadly correct I’d say that the Maronite radicals who argue for a strong separation between the origins of their own people and the Muslim and Druze of Lebanon are not on solid basis, just as Muslim Arabs who believe that they are predominantly descended from Arabians are also not on solid ground.

Evolution skeptical: not just fundamentalists


In the comments below Christopher Mims states:

But evolution? It seems as if denial of evolution comes from a place so basic — religious fundamentalism — that I wonder whether something like this could ever have even the slightest impact.

It’s hard to deny the relationship of religious fundamentalism and evolution denial and skepticism. But, I think it’s important to remember that in the United States the large critical mass of evolution-denying religious fundamentalists has resulted in a “bleed over” of the stance to people who aren’t religious fundamentalists. I know this anecdotally from friends who were of Roman Catholic and Mormon backgrounds who presumed that their religious orientation precluded an acceptance of evolution. In fact, my own first awareness that people might actually not believe in evolution came via a conversation with an evolution skeptic friend who was a nominal Roman Catholic. Nominal in that his family actually never went to church.

What Paul Bloom’s research suggests is that humans find the Creationist narrative intuitively plausible. But, the critical issue is that those who aren’t indoctrinated against the idea of evolution can be convinced of its plausibility.

Let’s look at how this distributes across society using the General Social Survey. The variable BIBLE asks if people think that the Bible is the actually word of god, the inspired word of god, or a book of fables, etc. This seems to be a reasonable approximation of whether one is a fundamentalist, a non-fundamentalist who still accepts the revealed nature of the Bible, or someone who denies the supernatural grounding of the Bible in totality. There are two evolution related questions I can cross with BIBLE. EVOLVED, which asks if humans developed from an earlier species of animal with a true/false response, and SCITEST4, which asks the same question but has a more graded set of responses. Please note that EVOLVED was asked in the mid-to-late 2000s, while SCITEST4 was asked in the 1990s.

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Evolutionary imperialism

So there’s a slick new webzine coming out, Evolution: this view of life. It’s another one of David Sloan Wilson’s projects. I don’t agree a lot with the specifics of David’s theories, but I admire his ambition. James Winters pointed me to the fact that they’re trying to raise money for this webzine via KickStarter. Their goal is $5,000. Having run much more bare bones websites for years this seems like a really modest amount in relation to their aims. I admire David’s attempts in this area enough that I gave some money. He tries a lot of things, many of which don’t succeed, but that’s science….

Notes on comments

I dislike cluttering this site with administrative notes, but I want to put this post up as a reference for the future. It’s not really aimed at regular readers/commenters, who know the explicit and implicit norms.

1) If you use quotation marks, make sure that you’re actually quoting something your interlocutor said, rather than adding them for effect (yes, believe it or not, people have quoted me, where the “quotes” were actually their own interpretation of what I intended)

2) It is generally not best to paraphrase someone else’s argument in your own words as a prologue to your own comment. Just quote the appropriate sections of text in your reply if you want it to frame your response. If you are engaging in paraphrasing to distill the argument of your interlocutor down to a pith, understand that subconscious tendencies are such that you’ll reshape that argument to better suit your response. In other words, you’re probably arguing with your own conception of their argument, not their argument as such. More maliciously some people just paraphrase because it makes setting up a straw man so much easier. That’s not nice. I have wasted a fair amount of time rereading posts to try and figure out how commenters came to a particular perception of my argument. I don’t take kindly to people telling me what I obviously really think, when I point out that their perception was wrong.

3) From that you can gather that inferring “between the lines” isn’t appropriate in most cases. It is part of normal human cognition, and you can’t help it to some extent. But being too liberal about the practice means that you’ll just distort the argument of the other person, who then has to waste their time correcting your misunderstandings. This gums up the exchanges because people have only a finite amount of time. Read as plainly as possible.

4) There’s no presumption here of symmetry. If the host asks you a direct question, answer and don’t evade. If the host tells you to drop a topic, don’t make the case for why you shouldn’t drop the topic. Wasting time trying to argue these issues is a banning offense.

5) I’m busy, and getting busier. I don’t respond well to people wasting my time. Some of the other commenters are busy too. It’s important to make exchanges “count.” Excessive posturing, and an obvious fixation on “winning” arguments with clever ripostes, are bannable offensives.

I’m not taking comments on this post, because as I said this post is more a placeholder so I don’t have to have the same stale argument over & over.

Note: See this companion post.

Unfrying the egg

Dienekes has a long post, the pith of which is expressed in the following:

If I had to guess, I would propose that most extant Europeans will be discovered to be a 2-way West Asian/Ancestral European mix, just as most South Asians are a simple West Asian/Ancestral South Indian mix. In both cases, the indigenous component is no longer in existence and the South Asian/Atlantic_Baltic components that emerge in ADMIXTURE analyses represent a composite of the aboriginal component with the introduced West Asian one. And, like in India, some populations will be discovered to be “off-cline” by admixture with different elements: in Europe these will be Paleo-Mediterraneans like the Iceman, an element maximally preserved in modern Sardinians, as well as the East Eurasian-influenced populations at the North-Eastern side of the continent.

This does not seem to be totally implausible on the face of it. But it seems likely that any “West Asian” component is going to be much closer genetically to an “Ancestral European” mix than they were to “Ancestral South Indians,” because the two former elements are probably part of a broader West Eurasian diversification which post-dates the separation of those groups from Southern and Eastern Eurasians. In other words, pulling out the distinct elements in Europeans is likely a more difficult task because the constituents of the mixture resemble each other quite a bit when compared to “Ancestral North Indians” vs. “Ancestral South Indians.”

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In it for the long run

Over the past six months we’ve seen the “Libyan revolution” stall and then succeed. There’s no doubt that the late Libyan dictator was a marginally sane megalomaniac. That being said, he’d been on better behavior over the past 10 years, dismantling his nuclear program for example. I can see the logic in wanting to overthrow him though, there’s a lot of built up historical memory in relation to the various terrorist groups he’s funded in Europe, as well as actions like bombing of Pan Am 103. But is anyone really surprised when things like this occur:

It was just a passing reference to marriage in a leader’s soberly delivered speech, but all week it has unsettled women here as well as allies abroad.

In announcing the success of the Libyan revolution and calling for a new, more pious nation, the head of the interim government, Mustafa Abdel-Jalil, also seemed to clear the way for unrestricted polygamy in a Muslim country where it has been limited and rare for decades.

It looked like a sizable step backward for women at a moment when much here — institutions, laws, social relations — is still in play after the end of Col. Muammar el-Qaddafi’s 42 years of authoritarian rule.

In his speech, Mr. Abdel-Jalil declared that a Qaddafi-era law that placed restrictions on multiple marriages, which is a tenet of Islamic law, or Shariah, would be done away with. The law, which stated that a first wife had to give permission before others were added, for instance, had kept polygamy rare here.

“This law is contrary to Shariah and must be stopped,” Mr. Abdel-Jalil told the crowd, vowing that the new government would adhere more faithfully to Shariah. The next day he reiterated the point to reporters at a news conference: “Shariah allows polygamy,” he said. Mr. Abdel-Jalil is known for his piety.

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Ancient DNA in the near future

I recently inquired if anyone was sequencing Cheddar Man. In case you don’t know, this individual died ~9,000 years ago in Britain, but the remains were well preserved enough that mtDNA was retrieved from him. He was of haplogroup U5, which is still present in the local region. Cheddar Man is also particularly interesting because he is definitely a Paleolithic hunter-gatherer, predating the Neolithic in Britain by thousands of years.

It turns out that no one is looking at Cheddar Man now. But that’s probably because money and time are finite. I was told that there are plenty of other specimens which would also probably be good candidates for sequencing in the Museum’s collection (this doesn’t seem to be a case where curators are being stingy and overprotecting of their specimens). That’s not too surprising. We’ll probably answer a lot of questions about the roles of demographic diffusion vs. cultural diffusion when it comes to agriculture soon enough (as in, over the next 10 years as techniques for getting signal out of old degraded and contaminated samples get better).