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March 12, 2005



Paleoanthro Primer

Over the past few days I read Bones, Stones and Molecules, which is a slim primer on the current state of paleoanthropology. The order is appropriate, old school fossil morphology tends to get a lot of play, with a secondary role for analysis of tool making and cultures and finally a tertiary spot for molecular phylogenetics. It makes sense since the authors start their survey back in the Miocene, long before stones (tools) are an issue and antedating any practical expectations of genetic extraction.

I'm not someone who knows that much about zygomatic arches and dental morphology, so the text was something of an alphabet soup of data that I had a hard time processing. Nevertheless, I think at under 300 pages (big text) it is relatively easy to digest. Additionally, they make extensive use of cladistics by crunching all the morphological characters into data analysis and statistical programs, so it isn't an artistic and impressionistic rendering of fossils. Molecular phylogenetics looms in the background as an independent method of corraboration of the trees that morphology spits out, and in general the two methods do tend to align, though I am sure that the authors massaged the data a bit here and there.

Though the book jacket states that the authors survey both Out-of-Africa and Multiregionalism, the latter is definitely frowned upon and one chapter on Australia seems to fixate on falsifying Multiregionalism by examination of Australian Aboriginal morphology and genetics. But, it seems that the authors make a stronger negative case against Wolpoffian Multiregionalism than they do for Out-of-Africa. The fossils are scattered in a fashion that it makes specific patterns difficult to tease apart, and there are many question marks that the authors choose to highlight. The book was published in 2004 before the Hobbit discoveries went public, but the authors allude to it pretty clearly in reference to Flores, and one of them offers that they have recovered a Neandertal skeleton from southern China (unpublished and going to press, literature searches didn't turn anything up). Such anomalies (Neandertals are traditionally a West Eurasian people), as well as the Flores finds, suggest to me that though classical Multiregionalism is unsupported, a glib assumption that recent Out-of-Africa and absolute replacement matches the data well is a bit of a stretch (at least universally). It is clearer what is false than what is true.

Posted by razib at 07:03 PM | | TrackBack


Headless "humans"

Jody over at PolySciFi made an offhand comment about organ farms in the context of headless bodies. Neglecting the reality that at some point we can probably play around with stem cells and grow individual organs, I don't get the "yuck" factor associated with this idea (I assume that a brain stem will be necessary, so they won't be strictlly headless, correct?). One of Jody's commentors referred to these things as "almost human." I am surely missing something, because I can't see how a neocortexless amalgam of cells is anything close to a human. Is someone "less human" if they lose a kidney or lung, or if their legs are amputated? I don't see humanity as essentially about the body, rather, it is about the mind.1

Now, I'm not a "ghost in the machine" believer, but, even if you accept that position it seems that the ghost resides in the brain (?). If you are religious and believe in a soul, does this change your position? Does the soul only exist coterminously with the body, so the body is sacred as well?

1 - I get the "yuck" factor in eating human flesh, but, the reasoning behind making use of human flesh is weak since the alternatives are so copious. To my mind the yuckiness of harvesting organs from brain-stem only things is far outweighed by the enormous benefits. I can intuitively understand why people would imbue sacredness to the body after death, but it seems the body is less important the rituals that mark the passing of the self, many traditions burn and cremate the remains after all.

Posted by razib at 06:00 PM | | TrackBack


Neocons

I have post titled "Neocon!" over at Dean Nation. Please post all comments over there, I get exhausted by political threads, so I don't want to read it here.

Update: Follow up post.

Posted by razib at 11:59 AM | | TrackBack


Market dominant Semites....

The Forbes World's Richest People rankings just came out. One thing that jumped out at me: #4 is a Mexican national, Carlos Slim Helu. I knew a girl who had the last name "Helou" (variant), and she wasn't of Latin American extraction, she was Lebanese. And sure enough, he is Lebanese Arab by ethnicity. Not knowing any Spanish, I can't find statistics about the overrepresentation of Arabs (usually Syrian or Lebanese of Christian faith) in the commanding heights of Latin American politics and business, but I get a definite impression that it is a "known" fact (individuals like Salma Hayek, Shakira Mebarak and Carlos Menem are too frequenty to be random sampling).

Any Latin American readers know of hard data?

Posted by razib at 12:25 AM | | TrackBack

March 11, 2005



Hold the defeminization!
Posted by razib at 05:14 PM | | TrackBack


Humans greedy for pig?

Pigs domesticated 'many times', at least, that is the inference based on mitochondrial DNA, passed from sow to sow. This point is important because the research seems to be offering up a dichotomy, imported pigs vs. idea diffusion, ergo, domestication of local pigs, but, what about admixture? Imagine that you have a small alien domestic pig population, which over the generations interbreeds with the local pigs. There will be phenotypic variance among the half-breed pigs, but repeated selection for the more "domestic" hybrids could result in perpetuation of the ancestral imported pig phenotype despite the influx (and eventual preponderance) of indigenous DNA on other loci where selection is not operating. To test this hypothesis I guess they would have to try to figure out the coalescence on the "piggy" loci in question, if you get a result where non-Middle Eastern and Chinese pigs are simply branches of the Middle Eastern and Chinese family trees,1 then perhaps those alleles radiated from a few domestication hearths. If the braches reach far back in pig genetic history for all the loci and Middle Eastern or Chinese branches are particularly diverse or old, then I think you can make a strong case for selection of traits of local pigs without much admixture or introduction of alien swine.

Related: "Racial Diversity" and The origins of phenotypic variation?.

1 - By analogy to our species, according to mtDNA non-Africans are simply subsets of the African family tree.

Posted by razib at 01:05 PM | | TrackBack


The Cycle
Posted by razib at 10:52 AM | | TrackBack


Autism and assortative mating

Rod Liddle (yes, him again) has an interesting article here in this week's Spectator magazine, suggesting that the rise in autism cases may be due to an increase in assortative mating. He attributes the theory to Simon Baron-Cohen.

I think the idea is a very long shot, but worth mentioning.

Posted by David B at 04:49 AM | | TrackBack

March 10, 2005



Fred on Evolution

Every now and then someone capable of reasonable thought writes out a long attack on evolution, and I feel like responding with a persuasive essay explaining why he is wrong. In fact, I have been known to do that in the past. But I don't anymore because I have found that the only people whose opinions I am likely to change are the easily persuaded. An intelligent argument from the other side would persuade them the other way.

Nowadays I usually just point to the Talk Origins Archive. It gives intelligent people a chance to change their own opinion -- and that is something that may be more likely than my changing it for them.

Addendum from Razib: Here is Panda's Thumb weighing in....

Posted by Thrasymachus at 10:17 PM | | TrackBack


Statistics Primer

So many of our posts are reliant on statistical understanding, which we don't write about too often, but Kim Swygert comes to the rescue with her series on the fundamentals of statistics. She starts off with a discussion on percentile, proceeds to Measures of Central Tendency, Measures of Variability, and today's topic is Scales of Measurement.

If you ever had any questions you wanted to ask a pyschometrician, well here's your chance.

Posted by TangoMan at 08:42 PM | | TrackBack


I'll See Your Gender Sensitivity and Raise You Some Cultural Sensitivity

I can just see the Swedish PC brigades having conniptions about which side of the IKEA discrimination issue to side with. You see, the Prime Minister of Norway has leveled the charge that Sweden's IKEA is discriminating against women because all of IKEA's instruction manuals depict men, or gender neutral figures, as the ones constructing the furniture.

However, IKEA feels that it isn't some eviiilll discriminatory throwback, no indeed, rather it sees itself in the vanguard of the cultural sensitivity movement, for it eschews the depiction of women building furniture in its manuals in order to be sensitive to Muslim feelings about women's proper roles.

Posted by TangoMan at 06:43 PM | | TrackBack


Love, lust and attachment

In the post on pair-bonding there was a question wabout the varieties of love, bonding, etc. Chapter 4 of Why We Love (see previous post) is devoted to analyzing and decoupling long term attachment, romantic love and lust. Of these three, long term attachment seems most related to "pair-bonding." The author notes, that:


  • fMRI images that sketch out brain activity associated with lust (exposure to erotic images) differ a great deal from the those associated with romantic love (in this case, the author performed many fMRIs on couples who were in the first flower of romantic love).
  • Lust is also correlated with testosterone, explaining why males and older women tend to have a higher libido (as women age, their estrogen level drops, so their relative level of testosterone increases).
  • Romantic love can feed into lust because dopamine (associated with the former) can induce the release of testosterone (associated with the latter).
  • The reverse can also happen, in that increased levels of testosterone (associated with lust) can release dopamine (associated with romantic love).
  • The relationship between lust and long term attachment (correlated with vasopressin and oxytocin in males and females respectively) is complicated, but in general the author offers that there is likely a mild negative relationship as the two "attachment hormones" dampen the release of testosterone and vice versa (though this is not a deterministic rule).
  • The relationship between romantic love and long term attachment is even more confused (ie; dopamine and its associated chemicals and vasopressin and oxytocin).

The narrative above is not totally convincing, and the "chemical soup" model is obviously simplistic (the author seems to acknowledge this in asides, but I don't think many readers will catch them). Additionally, she is using the standard Evolutionary Psychology method of focusing on average or universal tendencies so it is possible that different "strategies" are confounding her perception as substructured trends are being compressed together. There is an admission that both men and women vary in the level of basal testosterone in their systems, which tends to have a strong correlation with various behaviors (lots of testosterone ~ lots of sex),1 so perhaps the countervailing data points might simply be that chemical pathways settle at different equilibria from individual to individual.

Nevertheless she is able to map the soup-chemical pathway model on to some of the tendencies we see among people in the real world. There are cases where people have an instant attraction which later soldifies into love. Cases where you are friends with someone, and at some point either lust or love get triggered. There is the tendency for lust and romantic love to frade into attachment. More refinement of the models are needed so that description can be translated more clearly into prescription, at which point perhaps our mastery of the chemistry of love will have matured enough that a pill can trigger the appropriate reactions and phase change mental state upon a whim....

1 - Simon Baron-Cohen suggests that high testerone women and low testosterone men are better at math.

Posted by razib at 11:19 AM | | TrackBack


Orissa

Influence of language and ancestry on genetic structure of contiguous populations: A microsatellite based study on populations of Orissa (full text of article at the link). Neighbor-joining tree of genetic distances (DA) based on fifteen microsatellite loci among studied populations of India below.

Posted by razib at 10:25 AM | | TrackBack

March 09, 2005



Ideological Isolation, Part II

A year ago I wrote about how the books favored by the Left and the Right find little common ground in my post Ideological Isolation, which included a pretty nifty graphic, and now Kevin Drum reports on a study, also with a nifty graphic, that looks at the linkage patterns of the blogosphere's Left and Right political blogs and their respective choices for topics and focus on personalities.

Posted by TangoMan at 10:27 PM | | TrackBack


Lesson Learned from the Harvard "Hacking"

By now I'm sure we've all read the account of Harvard denying admission to 119 prospective students who accessed information in their own Harvard Admission accounts because Harvard considers this behavior to be unethical.

Unfortunately, the lesson learned by the rejected students will not be the one intended, rather it'll be that, as an executive, when you're caught with your pants down around your ankles, quickly shift the blame for the fuck-up onto someone else.

Harvard accuses these students of "hacking" into information that they had no right to access. What was the nature of the "hacking?" Simply backspacing on the URL within their account. There was no attempt to access restricted directories, there was no password generator used, there was no subterfuge in attempting to get information from secretaries.

The Harvard Administration placed the student acceptance letters into an open directory without password protection. Now, if they're smart enough in the ways of the internet to be able to read logfiles and determine who accessed which page then they're damn well smart enough to know that they should be placing sensitive information into folders with some security attached, and expectation of ignorance of backspacing is not a form of security.

Here's a rundown on how you too can hack the Harvard system. I've participated in some discussions on this where it's been argued that the information that these students accessed was similar to a file folder left in a private office, or a medical chart on a nurse's desk, and that the rejected students didn't have any right to look at those files. These types of examples use situations where there is an expectation of privacy that has been violated.

I've countered that the more appropriate anology is one where you are instructed to read page 67 of a magazine in a library, but on your own initiative you also read page 68, completely unaware that this is a punishable offense. Upon learning of your transgression of reading more than you've been directed, the instructor takes disciplinary action. In this scenario, the information is publicly available and while you're going beyond your instructions, you're not really reading anything that you shouldn't be reading. Or to put it more colorfully, as you're walking down the street you're told to look up into an office window to see a banner that's on display. When you purposefully glance at the window next to the one with the banner you see a naked person and upon learning of what you saw, your companion smacks you upside the head for your "unethical behavior" of seeing something on public display that he didn't instruct you to see.

Harvard's ass-covering is the result of their having a fundamental ignorance of the open nature of the internet. It is this very openness which allows Google and other search engines to crawl through a website's directory structure and to catalogue and index the entire site.

Further, if one really wants to get finicky about this issue, we can turn to the question of how to interpret the public/private aspect of information. Did the student's admission status become public once it was placed into an open directory, or only days or weeks later when the student is informed of the specific URL? The actions of the Harvard Administration are easily seen as supporting the contention that the information was public because it was placed in the open.

Cover your ass and shift the blame. Yep, an expensive lesson learned, indeed. In fact, these resourceful students, who know the lay of the land in which they operate, are precisely the types I like to hire. I suppose though, that it can be argued that these students erred in assessing which environment they really were operating within.

Posted by TangoMan at 06:38 PM | | TrackBack


Islam with Chinese characteristics...no, really!

I jump stumbled upon this interesting article, Islam with Chinese characteristics begins to take hold (username: gnxppublic password: publicgnxp). It is about the Hui1 community in China, and there were two points which really struck me as peculiar, first, there are female only mosques ("nusi") and, female imams who preach in these mosques!!! Does anyone know of similar phenomena anywhere else in the world? I have recently been promoting an idea that "obvious" implications of religious traditions become fixed through community consensus rather than a transparent chain of logic from first principles, I would offer that perhaps this "innovation" among the Hui is a function of their relative isolation (until recently) from the worldwide Ummah (Muslim community).

Here is a book review of a work entitled The History of Women's Mosques in Chinese Islam: A Mosque of Their Own. The reviewer concludes that geographic isolation of Muslims in China played a key role in religious innovations such as the nusi and female imams, in line with my hypothesis above.

1 - The Hui are to be distinguished from the ethnic Turkic Muslims of Western China, like the Uighers. The Hui are considered a "nationality" in China, but in practical terms they are basically Han who happen to be Muslim.

Posted by razib at 05:46 PM | | TrackBack


Child molestation in Pakistani madrassas

The Institute for the Secularisation of Islamic Society has a fantastic piece on instances of child molestation that has occurred in Pakistani madrassas and how it has been completely ignored by Western media. The effects of this story?

If they are true, the madrasa story is to Pakistan (and by extension to the Muslim world) what the analogous story was to the Catholic Church a few years ago—or for that matter what Abu Ghraib has been for the US occupation of Iraq. Both of the latter scandals have permanently scarred the institutions responsible for producing them. The consequences of inflicting the same sorts of damage on the Pakistani madrasacracy are incalculable—incalculably good, that is.

The charges also give some perspective to Islamic fundamentalists’ tedious habit of sermonizing at us about the supposed sexual dysfunctionality of “the West” and the superior moral virtue of “the Islamic East.”

The Asia Times columnist Spengler has recently produced an amusing quasi-parody of such a sermon in which he rails at the sexual depravity of “the West,” and which he jokingly claims to have gotten directly from Osama bin Laden.

Joke or not, such sermons ought to provoke the rejoinder that dar al Islam is not exactly the abode of virginal chastity that the fundamentalists would have us believe that it is. With gang rape in Punjab (cf. the Mukhtaran Bibi case), mass rape in Darfur, female genital mutilation across parts of Muslim Africa, and honor killings of girls in various Arab countries, it would appear to be time for our holier-than-thou sermonizers to introspect a bit and focus on some of their own sexual hang-ups. Add polygamy to the rap sheet, plus the weird Muslim obsession with burqa, chador and hijab; add the yet-weirder cult of the 72 post-mortem virgins, throw in stoning as a punishment for adultery, and then consider burial-alive as a punishment for homosexuality. XXX- rated Qur’anic literacy lessons seem pretty much par for the course in this context. In short, put it all together, and the sexual depravities of “the West” begin to look tame by comparison with what the Muslim world has to offer in the way of polymorphous perverse sexuality.

Hat tip: Reason magazine (print edition)

Posted by Arcane at 12:10 PM | | TrackBack


Aging

Rikurzhen touched on a topic I find very interesting. Here’s information that I hope others will find informative.

Here are a couple of sites for information on aging:

SENS (Strategies for Engineered Negligible Senescence)


Flow Chart of Biochemical and Physiological Interactions in Human Aging

Here’s my rough synopsis (you really should read the SENS site):

Aging is several processes occurring at the same time:

DNA damage. Mainly in mitochondria.

Body system changes. Changing hormonal levels. Changes in the brain’s regulation of body homeostatis. Different gene expression patterns in body tissues. Cell receptor responses change. (Possibly pre-programmed system changes as a delayed result of puberty.)

Organ changes. Various organs function with less efficiency. The immune system undergoes a significant decline.

Stem cells lose regenerative ability. (May be related to telomer shortening.)

Accumulation of cellular garbage.

Protein cross-linkage in extra-cellular protein. (Hardening of the arteries.)


Arguments against systemic DNA damage being the main driver of aging:

Except for certain mitochondrial diseases, most mitochondria continue operating with good efficiency.

For the tissues tested, aging seems to occur at the same rate in all tissues. DNA damage occurs much more frequently in some tissues, e.g., retina of the eye. If DNA damage drives aging, I’d expect certain tissues to be “older” than others.

Article: A Global View of Gene Expression in the Aging Kidney

Article: Young blood revives aging muscles, Stanford researchers find

While I believe all of the above aging factors play a role, I think the main driver is a body system affect. It could be the brain’s regulation of body homeostasis changes. (Perhaps genetically programmed changes or perhaps just cumulative failure of feedback systems.)

It could be a central reservoir of special stem cells with the ability to differentiate into all cell types loses its regenerative abilities. (Such stem cells may have recently been found in bone marrow. Article )


If aging is mainly a general system failure, it could still be driven by DNA damage. But it wouldn’t be global DNA damage. It would be DNA damage in specific cells such a special stem cells or special neurons involved in regulating body systems. Replacing or fixing those cells might reverse some aspects of aging.

Posted by fly at 09:17 AM | | TrackBack


The Office-USA

The British mockumentary "The Office" is coming to NBC. There seem to be some American twists. Check out the diversity clip (there is some funny brown-themed humor, but it gives you some bull about Active X so make sure to use IE Explorer).

Posted by razib at 12:42 AM | | TrackBack

March 08, 2005



DNA Damage and Aging

This may be of interest to the SENS/lifespan extension crowd.

While discussing aging with a colleague, she mentioned that the latest theory is that DNA damage is the proximal cause of aging, and that strategies to cure aging will be limited to future genetations by this fact.

I found a good review paper (PDF reprint online) on the topic of dsDNA damage and aging. I find it fairly convincing. A quick summary:

1. Hypothesis: oxidative damage to DNA causes aging
2. All of the thus far identified premature aging syndromes in mammals involve mutations in nuclear proteins (e.g., lamin A in progeria)
3. Nonhomologous DNA end joining (NHEJ) is a major pathway for the repair of double-strand DNA breaks, but it frequently fails to restore the original DNA sequence
4. Homologous recombination (HR) is the non-destructive alternative to NHEJ
5. Gametes use HR over NHEJ (the germline is immortal); as do birds and bats compared to land mammals (with a corresponding greater lifespan)

The SENS proposal for chromosomal DNA damage only seems to address telomere shortening. Stem cell therapy is one possible work-around, but not for all tissues. I cannot imagine a good regenerative technology to address this factor in aging. Any suggestions?

Posted by rikurzhen at 09:53 PM | | TrackBack


Paleo-protein extraction

75,000 year old proteins from Neandertals have been extracted, you can find the abstract in PNAS.

Posted by razib at 09:36 PM | | TrackBack


Reading Books is Hard!

Looking again at my old Psych 101 textbook earlier today, I found this passage:

Consider, first, not people but tomatoes. (This "thought experiment," illustrated in Figure 6.5 on the next page, is based on Lewontin, 1970.) Suppose you have a bag of tomato seeds that vary genetically; all things being equal, some will produce tomatoes that are puny and tasteless, and some will produce tomatoes that are plump and delicious. Now you take a bunch of these seeds in your left hand and another bunch in your right hand. Though one seed differs genetically from another, there is no average difference between the seeds in your left hand and those in your right. You plant the left hand's seeds in pot A, with some soil that you have doctored with nitrogen and other nutrients, and you plant the right hand's seeds in pot B, with soil from which you have extracted nutrients. When the tomato plants grow, they will vary within each pot in terms of height, the number of tomatoes produced, and the size of the tomatoes, purely because of genetic differences. But there will also be an average difference between the plants in pot A and those in pot B: The plants in pot A will be healthier and bear more tomatoes. This difference between pots is due entirely to the different soils -- even though the heritability of the within-pot differences is 100 percent.

[...]

For example, in the much-discussed book The Bell Curve: Intelligence and Class Structure in American Life (1994), the late psychologist Richard Herrnstein and conservative political theorist Charles Murray cited heritability studies done mostly with whites to imply that the gap in IQ scores between the average white and the average black child can never be closed. Wade & Tavris, Invitation to Psychology, 1999, pg. 212

Compare that with this:

As we discussed in Chapter 4, scholars accept that IQ is substantially heritable, somewhere between 40 and 80 percent, meaning that much of the observed variation in IQ is genetic. And yet this tells us nothing for sure about the origin of the differences between races in measured intelligence. This point is so basic, and so commonly misunderstood, that it deserves emphasis: That a trait is genetically transmitted in individuals does not mean that group differences in that trait are also genetic in origin. Anyone who doubts this assertion may take two handfuls of genetically identical seed corn and plant one handful in Iowa, the other in the Mojave Desert, and let nature (i.e., the environment) take its course. The seeds will grow in Iowa, not in the Mojave, and the result will have nothing to do with genetic differences. Herrnstein & Murray, The Bell Curve, 1994, pg. 298

Oopsie. Isn't there also a discussion, on page 313, of how heritable group differences are not necessarily any more or less immutable than environmental differences?

Its shocking to me -- shocking -- that the authors of a textbook couldn't be bothered to actually read their sources and/or report them accurately.

Posted by God Fearing Atheist at 06:18 PM | | TrackBack


A Phoenician education

Check out Jonathan Edelstein's three part backgrounder on Lebanese politics.

In related news, Reul Marc Gerecht espouses Sunni majority rule in Syria in The Weekly Standard. So will Jordan have to absorb all the Christian refugees from Iraq once a Syrian option is closed to them? Syria may be a authoritarian or totalitarian state, but not in the realm of religious freedom, at least according to The State Department.

Via Dean Nation.

Posted by razib at 02:17 PM | | TrackBack


Education and segregation

Razib posted recently reporting on a controversy in the UK over comments by Trevor Phillips, the (black) Chairman of the official Commission for Racial Equality. Phillips was reported as recommending that black boys should be separately educated from whites to help remedy educational under-achievement.

Razib included a link to some recently published educational statistics. These are very interesting, and I will be analysing them more fully soon. The present post is just a quickie to correct some possible misunderstandings about what Phillips actually said, and some errors in my own initial comments on Razib's post.

First, Phillips's comments were made in a BBC TV documentary which was shown last night, a day or so after the fuss broke out. In the context of the documentary, Phillips's suggestions were more modest and tentative than the hype implied. What he said was just that we ought at least to consider teaching black boys separately for some lessons in some subjects. Moreover, in context his emphasis seemed to be more on separating boys from girls than blacks from whites. Indeed, I wondered if his reference to separate lessons for 'black boys' had simply been misunderstood, and that he wasn't suggesting a racial separation at all. However, if it was a misunderstanding, he doesn't seem to have corrected it.

In comments on Razib's post I also pointed out that Phillips claimed to be following an American precedent from a school in St Louis, where, according to the London Times, black boys were taught separately in a different classroom. Again, having seen the TV documentary, this account is misleading. The St Louis school was shown in the documentary, and there was no suggestion of deliberate racial separation, which could hardly arise as the school was 99% black already! The separation was only of boys from girls.

Finally, in my comments I said that the new education statistics seemed to include mixed-race categories for the first time. This is incorrect: the classification was introduced a few years ago. I will cover this in my further analysis.

Posted by David B at 02:43 AM | | TrackBack

March 07, 2005



Geography predicts human genetic diversity


Geography predicts neutral genetic diversity of human populations
is a paper in Current Biology which supports a "Recent African Origin" (RAO) model for H. sapiens. I noted a month ago that Richard Dawkins, an evolutionary biology consensus bellwether, if not an outstanding researcher himself, has promoted the alternative (and often under-publicized) Out of Africa again & again model in The Ancestor's Tale, which posits periodic migrations out of the Africa that washed over Eurasia as well as non-trivial levels of hybridization with local homonid populations in various regions. This paper falls in the camp of the current "Standard Model" which emphasizes one migration and replacement. Unfortunately, neither the abstract above nor the press release is very detailed or specific, though in the latter there is the assertion that "The loss of genetic diversity along colonization routes is smooth, with no obvious genetic discontinuity, thus suggesting that humans cannot be accurately classified in discrete ethnic groups or races on a genetic basis."1 Neither was the supplemental data particularly illuminating as to the loci they used in their model. Someone with full access might enlighten me on that last particular point.

1 - The frequencies of various HLA alleles may also change at a constant rate in a clinal fashion so that "objective" or typological classification may pose difficulties, but, that does not falsify the reality that a likelihood of match between two individuals is proportional to geographic distance between them in terms of origin, and that match can be very important indeed. Though the clines may show no discontinuities, population densities often do, so in the service of pragmatism one might simply assign "boundaries" between groups where the density of individuals on the ground is the lowest so as to do the least damange when classifications have serious consequences. I'm saying a classification scheme must be judged in the context of ends to which that scheme is being devised. "Accuracy" is in some ways an illusion because the human body is simply a collective of cells encoded by bits of DNA which may have disparate phylogenetic histories-race may well be a reification, but that need not be an insult. I am one who leans toward precision as opposed to accuracy as the prime value, because accuracy can only be judged by its fruits in this particular case. Many of these "race exists vs. does not exist" debates are quibblings over very similar data sets where a few words like "significant" are recalibrated or shaded in various directions.

Posted by razib at 11:18 PM | | TrackBack


The Bond(s)

Perspectives on human attachment (pair bonding): Eve’s unique legacy of a canine analogue is a paper that examines the peculiarites of human pair-bonding and relative monogamy in light of our phylogenetic history and location, that is, our nearest relatives in both contemporary genetic distance as well as the past resemble the 95% of mammals which do not exhibit a great deal of long term pair-bonding, let alone male mate provisioning and parental investment. The Copernican Revolution might have "decentered" humanity's place in the universe, but our evolutionary path seems very peculiar, not only do we not conform to Rensch's Rule in an intraspecific context (between subpopulations), but we do not fall in line when examined comparatively with other homonoids. Human pair-bonding seems likely to be related to our extraordinarily long childhoods, but Helen Fisher has suggested that cross-cultural comparisons tend to converge upon a median figure of ~4 years for male-female pair-bonds, implying that the "distant father" is a feature, not a bug.

Addendum: Note that in pre-modern conditions it seems plausible if the father remained alive he would remain close to his children even if a relationship with the mother foundered as men and women are unlikely to switch bands or villages very often (exogamy would impose a one time transition depending upon matrilocality or partilocality).

Posted by razib at 04:59 PM | | TrackBack


Scents & perfumes

My friend Chandler Burr has an article in The New Yorker on perfume. Not really related to this weblog's content, but this is a big day for him, so I am giving it a blurb. Readers might find The Emperor of Scent or A Separate Creation of interest.

Posted by razib at 03:20 PM | | TrackBack


Snap

In Individualism versus "sexual proprietariness" Theresa linked to this article in Der Speigal which notes "that the percent of schoolgirls wearing headscarves in the Berlin district where Hatin was killed has gone from virtually none to about 40 percent in the past three years." If you have read anything else about the changes in the European Muslim communities since 9/11 this should not be surprising, a new wave of "piety" signalled by "traditional" dress seems to be sweeping these enclaves as they close ranks against the perception (to some extent true) that the host societies reject them and will never accept them.

This sort of snap change in cultural norms and values within such a short period of time almost simultaneously throughout a community makes analogies to genetic or even linguistic change rather difficult when you attempt to construct plausible projections. Many models seem to posit a vertical chain of transmission (parent -> child), but when it comes to horizontal modes (friend -> friend) humans are as culturally promiscuous as bacteria are genetically. Those who project Muslim demographic domination of Europe within the generation and those who rebutt it are working with simplified models, but what else do they have to grasp on to? Culture defies predictive modelling as far as I can tell aside from the most trivial cases.

Consider the contrasting history of Christianity in South Korea and Japan. In 1600 ~10% of Japanese were Christians. Much of Kyushu had been Catholicized and Nagasaki was as Christian a city as 5th century Constantinople. But under Tokugawa Ieyasu Christianity was crushed to a pulp in Japan. When the nation opened itself to outsiders in the 19th century Westerners miraculously found isolated communities of "Secret Christians" who had persevered. But most of these believers had been transmuted by centuries of dissimulation, and often they turned away with a sense of alienation from the new churches founded by Westerners.1 Though some Japanese did convert to Christianity in the 19th century, by and large a second flowering of the faith did not occur. Christianity had influence far above its numbers, and there are suggestions that many female members of the imperial family converted, but in general Japan remained peculiarly a modernized and Westernized but non-Christian state. Today Japanese Christians are rather like mainline Protestants, and there are even Unitarians amongst them, you see little evidence of evangelical fervor common in other nations.

For instance, South Korea. Unlike Japan South Korea has not had a long history of Christianity, but today it is among the premier Christian nations in the world when measured in the number of missionaries in sends out. Despite the fact that only 1/4 of South Koreans are Christian! In 1945 the number was less than 5%, so the growth has been fantastic...but, according to The Korea Yearbook it seems that it levelled off in the 1990s (some estimates suggest that the rate of growth of Buddhism surpassed Christianity throughout much of the decade). Both the spectacular growth of Christianity and South Korea and the levelling off of the rate of growth in the 1990s were somewhat surprising.

The examples of South Korea and Japan both illustrate to us the reality that our understanding of human societies still remains in a pre-atomic age, they are basically magical blackboxes about which we concoct theoretically unscaffolded conjectures as we attempt to assemble alchemical formulae in reference to perceived patterns and trends, but high levels of prediction are viable only for events of the past, not for those of the future. What changed in the "Japanese soul" which made a once Christianity-receptive population rather apathetic and uninterested? Why is it that only ~1/4 of South Koreans seems to be hyperreceptive to Christianity?2

The only real lesson to be learned is greater caution. We have to utilize the few tools we have, and grandiloquent claims of insight must be tempered by the poor record of sociohistorical prognostication.

1 - One ethnography I read indicates that these remnant communities have by and large lost the battle for their continuity and many of the youth are melting into non-Christian Japanese society, which shares the same sacral motifs, though not the core belief structure.

2 - I suspect that it has to do with Christianity's appeal to the "forward classes" of Korean society. If the modern negative correlation between high SES and birthrate holds for South Korea one might even suggest that the 25% value is metastable, as there is balance between vertical diminishment (Christians not reproducing themselves) and horizontal growth (the inflow of converts).

Posted by razib at 02:51 PM | | TrackBack


The end of the Andaman Islanders?

Extinction threat for Andaman natives. Nothing much more to say.

Posted by razib at 02:23 PM | | TrackBack


Imperialism before history

About 6 months ago I refreshed my knowledge of pre-European antiquity by reading History of the Ancient Near East by Marc Van De Mieroop . The most surprising aspect of this survey for me was the revelation of the expansion from Mesopotamia after 4000 BCE of a cultural complex (centered on cities) across much of the Levant and into southeast Anatolia, and, the subsequent collapse of these "colonies" in the 3rd millennium, to be replaced by indigenous high civilizations.1 Because this was a period when narrative historical records were scant we do not know the details of how and why Mesopotamians exported their culture to other urban centers in the Near East, and we also will likely never know how or why there was a distinct retrenchment after centuries of domination. With the rise of a West Eurasian information network Mesopotamian languages and motifs seem pervasive when the light of history allows some level of clarity in our perception of the past, but, the material culture never again would show such a clear stamp of Mesopotamian influence. So, with this knowledge, it is not surprising that the city-state of Mari in modern day eastern Syria might have been built by Mesopotamians to serve very specific ends, rather than being the end result of locally organic processes.

The more general and less antiquarian point is that though the ancients and moderns differ, we are united by a common nature, and common wants, impulses and cognitive tools. Without extensive written records we will never be able to put flesh upon the skeleton of the first Mesopotamian foray into cultural expansion, dare we say, imperialism? But, I suspect that we can infer that perhaps the flesh would not be different in character from what we have observed in a thousand other specific instances of human history. In the late 19th century Europeans scrambled to claim every piece of Africa, but two generations later they abandoned most of the continent within 15 years. Pulses of demographic and intellectual energy periodically seem to well up from favored locales, to wash over their neighbors, and eventually recede or sink into the substrate.2

My final point would be that in an peculiar twist a greater awareness of evolutionary psychology, and the permeation of disparate modern cultures with universal motifs, might remind many students of history that the same principles apply across time as well as space. Some of the sillier ideas about the peculiar nefariousness of Western culture and the Edenic nature of non-Western culture are easily rebutted when viewed in this intellectually synthetic light.3

Via Dienekes.

Related: Primitive Warfare.

1 - Such assertions are based on archeological conjecture, but nonetheless, the author seemed confident that material continuities and discontuities were rather obvious.

2 - Just as European colonial ventures changed the indigenous cultures which they dominated for generations irrevocably, so Mesopotamian culture served as a model which others retooled to their own preferences. No doubt very similar dynamics of elite emulation and demographic amalgamation played their roles....

3 - It would also help in dismissing unqualified assertions that love was "invented" by Provencal poets or that consiousness was attained first by classical Greeks.

Posted by razib at 02:08 AM | | TrackBack

March 06, 2005



Across the pond....

Black girls overtake white boys. The article notes the increasing proportion of black African students, and implicitly suggests that in terms of educational metrics they should be viewed separately from West Indians. The relative educational success of black girls in the UK should be an interesting test of the importance of racism in shaping economic prospects in the coming years as this cohort is tracked. On a somewhat bizarre note, Britain's Commission for Racial Equality is suggesting that black boys need to be segregated to improve their performance. To me, this is the sort of peculiar outcome of excessive focus on group level identity that is so easy to lambast and predict. I know I am somewhat idealistic, but a society with a "Commission for Individual Opportunity" would seem to better reflect Enlightenment values, no matter the pragmatic need to organize and mobilize based on ethnic identities. In any case, if peer socialization tends to enforce a certain set of values, it seems that a different form of separation might be warranted for academically challenged young black males, rather than segregation as a group from the general student population, it seems that their dispersion might disrupt an anti-academic environment.1

Related: You can find many statistics here, control-f "GCSE" for the data sets that the story above is based on.

Addendum: GCSE in Wikipedia.

Via Jacquline & Randall.

1 - Seeing as how black outmarriage in England hovers around 50% (more for males, less for females), the difficulties of black males will be a temporary phenomena sans further immigration because blacks in Britain will be a temporary phenomena.

Posted by razib at 11:35 PM | | TrackBack


Sexual dimorphism differences?

Greg's post on the slow pace of evolution of sexual dimorphism referred to a Rogers and Mukherjee paper which concluded that this sort of phenotypic difference between males and females would evolve very slowly (common sense, selection for size in males would result in a correlated response in increase in size of their daughters). It was published in 1992 in Evolution, and I can't seem to find it online (I'm not paying for JSTOR!). But, I did find this interesting paper: Human size evolution: no evolutionary allometric relationship between male and female stature. The paper analyzes cross-cultural statures and concludes that Rensch's Rule, where sexual size dimorphism increases with size where males are the larger sex, but decreases with size where females are larger,1 does not apply to humans. The paper does imply there are mild deviations from the modal 1.07 stature ratio between males and females, though it seems possible this could be explained by different nutritional intake when it is greater than the modal value. If you are not interested in the technical details of allometry the full paper does have a long list of heights of males and females for various populations that might interest data nuts....

1 - To be clear, this rule is generally understood in the interspecific context, but, it should also apply within species with a reasonable amount of population substructure.

Posted by razib at 09:15 PM | | TrackBack


Mouse/Human Brain

Randall has a post on creating mouse/human chimeras whose brains contain a significant percentage of human neurons. Randall focuses on the possibility that when introduced at an early development stage human cells could lead to human brain structures and more intelligent mice. I hope his post generates an interesting discussion.

I want to consider a side topic related to this GNXP post on bird neurosystems. Human biodiversity gives insight into how IQ varies with human biology. What insight can be gained by comparing animal neural systems to human systems?

What makes humans more intelligent than animals? Is it the increased mass of specific brain regions? Is it brain organization? Or myelinization? Or different types of neurons for specialized purposes? Or differences at the molecular level such as synapses, brain transmitters, and receptors? Is it an extended human infancy that permits gradually organization of efficient learning patterns?

Various species have taken very different evolutionary paths. I believe it is unlikely that human brains are best (in the sense of IQ) in every way. How might animals have evolved superior neural processing compared to humans?

Possibilities are new types of neurons that might improve certain types of low-level function, more efficient neurons, e.g., smaller neurons that allow higher density processing, better brain organization for specific functions such as hearing, sight, or smell, or plasticity that allows retraining throughout lifespan.

Could we build a brain that incorporated the best brain features that evolution has produced in hundreds of millions of years of evolution in diverse animal species?

(From an algorithmic perspective I’ve long been bothered that different species couldn’t share their best evolutionary “discoveries”. Seems a waste. Now biotech could improve the evolutionary algorithm by providing mechanisms for such sharing.)

(I’m interested in links that that provide an overview of how animal neurons and neural systems differ from those in humans.)

Posted by fly at 08:05 PM | | TrackBack


An explication of assumptions

The Conflict Within - The Left's Version of Creationism has wended its way back and forth over the general path of the topic, but in the process, I think various issues have been confounded. So, this post is simply a review, or, an attempt to make explicit what I believe are background working assumptions (regular readers can probably skip this post).

First, I think there are various categories or types of thinking when it comes to the intersection between biology and the human sciences:


  1. Blank slate: which basically means that the only preprogrammed or primed aspects of our nature are bestial impulses like hunger or elimination.
  2. Operational Blank Slate: An admission that some aspects of our complex behavorial functioning are biologically shaped, bounded or rooted, but a declaration that the complexity of the phenomena and upstream variables defy analysis.
  3. Evolutionary Psychology: An acceptance of broad human universal tendencies, excepting (usually) sex differences. In other words, the loci which influence our behavior are nearly monomorphic so that one allele is exhibited in frequencies approaching fixation (100%). This mentality tends to reject intergroup differences and neglects individual (intragroup) differences.
  4. Behavior Genetics: An acceptance of salient individual differences which shape predispositions and life path probabilites. In this case, loci are not monomorphic, and two different polymorphisms, allelic variants, tend to result (on average) in different behavorial expressions.
  5. Human Biodiversity: An acceptance of different frequencies of alleles that give rise to different behaviors in different groups. That is, despite overlap, the frequency distributions of various polymorphisms vary from group to group, ergo, their average response to the same environments might also vary.

This is grossly simplistic, and I've focused on behavorial aspects so as to emphasize the most controversial elements of human biodiversity, I suspect that a far greater number of people are open to accepting human biodiversity's relevance in the context of tissue rejection than they are when it comes to intelligence or personality. In any case, on last three points, each is nested within the other when it comes to affirmation of relevance, so if you accept human biodiversity, you tend to accept behavior genetics and evolutionary psychology, and if you accept behavior genetics you tend to accept evolutionary psychology. But, the arrow of paradigm acceptance does not flow the other way. The main promoters of evolutionary psychology, John Toobey and Leda Cosmides, tend not to accept the salience of human biodiversity, and offer behavior genetics only benign neglect. Similarly, behavior geneticists, whatever their personal views, tend to avoid broaching human biodiversity, though the latter seems like a plausible implication of the former.

But when it comes to public debates that are politicized, the five groups tend to compress themselves into a dichotomy, so that individuals who espouse the first two propositions act as if they agree on points of substance, and, they treat those who espouse the last three propositions as if they were in one camp. The reasoning is simple: the small minority of individuals who are willing to publically espouse the salience of human biodiversity are far easier to denounce and rebutt than those at the biological antipode who focus on human universals. Most of the particulars in the original sociobiology controversy did not give much thought to human biodiversity (the exception was Bernard Davis, who was a supporter of Jensen). The same issue crops up in the later evolutionary psychology controversies, as some of the main proponents of the paradigm made explicit and grand gestures against human biodiversity, but their opponents nevertheless termed them "racists" or "Social Darwinists." The case with behavior genetics is far more muddled, and frankly the connection between it and human biodiversity is more transparent so "demonization" is not nearly as rhetorically contrived.

But the whole point of it is that people like Richard Lewontin are not insufferable because they reject human biodiversity, in a "strong" form most intellectuals reject it out of hand, rather, it is because they reject evolutionary psychology by attacking human biodiversity! They know very well that there is some confirmation bias in favor of evolutionary psychology from the general public (it "makes sense" to most people), so they want to hitch its wagon to something that the public couples with rejection bias. This is politics, not science, and it makes good faith discourse rather difficult.

Let me finish with a quote from the Lingua Franca piece that Jason linked to a few months ago:


Lewontin, who married his high school sweetheart and can to this day be seen walking hand in hand across Harvard Yard with her, takes a much harder line. "I'm a man, and I don't go around screwing young girls," he says. "I'm human, and so I have to be explained."

This, from a man who has an M.S. in mathematical statistics.

Posted by razib at 11:45 AM | | TrackBack


For entertainment purposes only....

A data set of two points says nothing in and of itself, but, for your amusement:

Two reviews of The Blank Slate, in The Nation and National Review.

Posted by razib at 10:18 AM | | TrackBack


New Fossil Hominid Finds

From the press release:

A total of 12 early hominid fossil specimens were discovered, including parts of one individual's skeleton. Portions recovered thus far include a complete tibia, parts of a femur, ribs, vertebrae, clavicle, pelvis, and a complete scapula of an adult whose sex and stature are yet to be determined, although it is already clear that the individual was larger than Lucy. In addition to this discovery, skeletal parts of other individuals were found in different localities in the area. These discoveries include isolated teeth, and elements from below the neck (arm bones, leg bones, phalanges).

[...]

Based on the associated animal remains, the team believes that the hominid fossils are likely between 3.8 to 4 million years old. This will place the new fossils in time between the earlier 4.4 million year old Ardipithecus ramidus partial skeleton and the younger 3.2 million year old "Lucy" partial skeleton of A. afarensis. The team hopes that the new discoveries will allow scientists to connect the dots -- furthering our knowledge of this important time period in human evolution.

Posted by God Fearing Atheist at 04:19 AM | | TrackBack