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December 24, 2004



Merry GravMas

I hope that everyone enjoys their Christmas and because our readership so heavily skews to a science literate audience I thought most would enjoy a little sci-fi story written by James P. Hogan, celebrating the birth of Sir Isaac Newton, born on Christmas Day of 1642.

Merry Gravmas

"Is that you, Li?" Cheng Xiang called, looking up from the notescreen propped against his knee. He had been amusing himself with a few tensor integrals to clear his mind before taking his morning coffee.

The sounds of movement came again from upstairs. Moments later, his ten-year-old son appeared, floating down the staircase on an anti-g disk. "Good morning, father."

"Merry Gravmas."

"And to you." Li hopped off the disk and stood admiring the decorations that the family robot had put up overnight. There were paper chains hanging in hyperbolic catenary curves and sinusoids, Gaussian distribution bells, and pendulums wreathed in logarithmic spirals. In the corner opposite the total-sensory cassette player, there stood a miniature apple tree with binary stars on top, a heap of gaily wrapped gifts around its base, and its branches adorned with colored masses of various shapes, a string of pulsing plasma glows, and striped candles shaped like integral signs. "It looks nice," Li said, eyeing the presents. "I wonder what Santa Roid has brought this year."

"You’ll have to wait until your brother and sister get here before you can open anything," Xian told him. "What are they doing?"

"Yu is sending off a last-minute Gravmas present to a schoolfriend over the matter transmitter to Jupiter. Yixuan is helping Mother program the autochef to cook the turkey."

"Why does everyone in this family always have to leave everything until the last minute?" Xiang grumbled, setting down the screen and getting up. "Anyone would think it wasn’t obvious that the ease of getting things done varies inversely as the square of procrastination."

Li walked over to the window and gazed out at Peking’s soaring panorama of towers, bridges, terraces, and arches, extending away all around, above, and for hundreds of meters below. "How did Gravmas start?" he asked his father.

"Hmph!" Xian snorted as he moved to stand alongside the boy. "Now isn’t that typical of young people today. Too wrapped up in relativistic quantum chromodynamics and multidimensional function spaces to know anything about where it came from or what it means. It’s this newfangled liberal education that’s to blame. They don’t teach natural philosophy anymore, the way we had to learn it."

"Well, that kind of thing does seem a bit quaint these days," Li said. "I suppose it’s okay for little old ladies and people who --"

"They don’t even recite the laws of motion in school every morning. Standards aren’t what they used to be. It’ll mean the end of civilization, you mark my words."

"You were going to tell me about Gravmas . . . "

"Oh, yes. Well, I presume you’ve heard of Newton?"

"Of course. A newton is the force which, acting on a mass of one kilogram, produces an acceleration of one meter per second per second."

"Not a newton. The Newton. You didn’t know that Newton was somebody’s name?"

"You mean it was a person?"

Continue reading Merry Gravmas.

Posted by TangoMan at 11:59 PM | | TrackBack


Merry Christmas Aziz!

As my Christmas present to my friend Aziz Poonwalla, I point readers to The First Annual Brass Crescent Awards for the Islamic Blogsphere. Who says atheists can't practice religious ecumenicalism?

Update: And Merry Christmas to everyone!

Posted by razib at 01:09 PM | | TrackBack


Creationist Behavior Genetics

I thought this was pretty cute. After explaining some recent behavior genetic research into female infidelity and telling their readers that "it certainly would not be a threat to a biblical worldview," the creationists at Answers in Genesis go on to give their own explanation of heritability:

In a fallen world, in which genes are corrupted by random copying mistakes, there may well be adverse effects of such mutated genes on behavior. Pastors know that certain parishioners are more predisposed to a certain class of sin than others. When person ‘X’ falls, it is generally in the same direction—whether that be stealing, pride, gluttony, substance abuse, spousal abuse, infidelity, etc. Person ‘Y’ in the same congregation tends to fall in a consistent direction, too, only it’s not the same direction as for ‘X’. They both have recurring weaknesses, but each is for a different class of sin.
Posted by God Fearing Atheist at 01:54 AM | | TrackBack

December 22, 2004



Surprise: North Asians Outperform Greeks in Visuo/Spatial Tasks

Although no disparity in the general factor was found, Demetriou et al. (in press) uncovered large differences in visuo/spatial abilities between their Chinese and Greek samples.

Not very exciting in itself. But what I did find interesting was their perferred explanation, which I haven't seen (or don't recall having seen) before.

In the present case, the assumption would be that the experience of learning the Chinese logographic system generates a special inter-wiring in the brain that supports and facilitates visuo/spatial processing. Indeed, recent neuroimaging studies show that thinking about Chinese (Tan et al., 2001) or Kanji characters (Bihan, Klein, & Dohi, 2002), which is the Japanese system of writing that is very similar to Chinese, activates many more brain areas in both the right and the left hemispheres than when thinking about phonetic characters. Interestingly, thinking about Chinese logographs activates an area in the frontal cortex (Tan et al., 2001) that is involved in executive control and the integration of different processing components (Goldberg, 2002). This is in line with the finding of the present study that Chinese excel in interference control. It is worthwhile to suppose that this kind of differentiation, even if local and domain-specific at the beginning, may eventually be reflected into more general intellectual characteristics, such as the overall thinking styles that may characterize different cultural groups. For instance, visuo/spatial processing, which is known to have a wholistic style of representation and processing (Corballis, 2003 and Hoffman, 1998), being a powerful mode of thinking in Chinese and other eastern cultures which share similar logographic systems, may be responsible, to some extent, for the qualitative differences between thinking in the east as compared to the west, mentioned in the introduction (Nisbett, 2003).

Of course, they could not rule out heritable differences. North Asians could be culturally capitalizing on their already-present abilities in the form on complex written scripts.

Reference:

Demetriou, A. et al. In press. The architecture, dynamics, and development of mental processing: Greek, Chinese, or Universal? Intelligence.

Posted by God Fearing Atheist at 08:52 PM | | TrackBack


A Lingua Franca Classic

Dusting off my bookmark shelf and I found a link to a memorable 1999 Lingua Franca article about the Sociobiology Wars. The link was, of course, as dead as Lingua Franca, so I ran it through the always useful Wayback Machine: Oh My Darwin!: Who's the Fittest Evolutionary Thinker of Them All?. There's a nostalgia factor here because this article was probably my first encounter with the topic, so anyone curious or new to the "Gould vs. Dawkins" rift might want to check it out. Those that have already read book-length treatments of the topic like Defenders of the Truth or The Triumph of Sociobiology probably won't get much more out of it than they already know outside of a few Hamilton and Pinker quotes they haven't heard before. ;)

Posted by Jason Malloy at 07:53 PM | | TrackBack


Green Beard Ethnic Nepotism? [Yes, Another Post On This]

Sailer and Salter's advocacy of kin selected ethnic nepotism using similarity data faces a major theoretical hurdle.

Evolution by natural selection concerns the change of the frequency of a specific allele at a given locus. In this sense, an allele competes with other alleles at this locus. It does not matter whether the effects of an allele increase the frequency of some alleles at other loci, a gene simply has to augment its own frequency to be evolutionary successful. For this reason, an allele that influences an organism in a manner that this individual behaves altruistically towards other individuals which are genetically similar to it with respect to other loci is neither selected for nor against. But genetic similarity theory focuses on overall genetic similarity, which basically includes all these irrelevant genes or loci. Instead, the question should be whether a gene is able to detect (based on phenotypic effects) whether another organism also has this allele at the same locus, then preferential behavior towards this organism is actually a better strategy than towards other organisms. But this scenario is simply the green beard effect, which as above said is usually excluded as a real possibility. This criticism has already been put forward by other authors (e.g., Mealey, 1985)...Standard kin selection theory, however, is able to give a possibility of the evolution of altruism. When a gene causes altruism towards a relative, this relative has—with a determined probability—the same gene identical by descent, and a fortiori identical in state. This is a clear way in which an allele can benefit the same allele in another organism (at least with a certain probability). (Brigandt in-press, pg. 10)

Dr. Harpending agrees with this criticism, but unlike Brigandt, apparently sees green beard effects as a possiblity. I want to take a look at this.

In some ways, green beard effects can better account for the peculiarities of ethnic conflict. Brigandt writes, with respect to van den Berghe's more traditionally Hamiltonian approach [1], that we would expect to see gradients of nepotism and ethnic conflict depending on how large the kinship coefficient is in any particular case. For example, we would expect Frenchmen to behave more altruistically toward each other than toward Englishmen, but more altruistically toward Englishmen than toward Poles. Wilson & Daly (via Jason) take this to its logical conclusion by suggesting "selection would have also favored altruism towards monkeys over dogs and mosquitoes over marigolds." However, "ethnic phenomena as ethnocentrism often have not only rather clear, but also distinctive boundaries. Either you are accepted as a fellow ethnic, or you are not. This does not conform to homeopathic altruism."

But this wouldn't be so strange if they are green beard effects. Ingroups and outgroups, according to the green beard hypothesis, are clearly delineated; either you are a member of the group (have the green beard gene or genes) or you are not (lack the green beard gene). Still, I see more problems and inconsistencies than solutions. For example:

1) If ethnic nepotism is a green beard effect, similarity data is still irrelevant. What matters is the presence or absence of the green beard gene (or tightly linked genes) but not similarity of other alleles across all loci.

2) Though possible, green beard effects are very rare. Dr. Harpending mentioned the fire ant gp9 locus, but an additional search of the literature yeilded only two more examples, within the slime mold Dictyostelium and possibly the poison-antidote system of bacteriocin producing bacteria.

3) The hypothesis would require the parallel acquisition of different versions of these genes in all ethnic groups that exhibit nepotism. Coupled with the second point, it seems highly unlikely that an ultra-rare phenomenon would repeatedly evolve in such a short amount of time, within such a phylogenetically exclusive group.

Minimally, this needs to be subjected to experiments before we jump on the bandwagon.

Related:
Ethnic Genetic Interests: Part 2
Ethnic Genetic Interests
Interracial Marriage: Salter's fallacy
Limits to Hamiltons Rule
On Genetic Interests
Dissin' Dawkins

[1] I say Hamiltonian approach because van den Berghe, unlike Rushton and (apparently) Salter, relies on the relatedness of individuals by descent and not their allelic similarity across all loci.

Posted by God Fearing Atheist at 03:57 PM | | TrackBack


Debunking Anti-Testing Nonsense

Kevin Drum has a post over at his blog about affirmative action, and many commentators, in an attempt to defend large-scale preferences, have questioned the validity of standardized tests. Most of their criticisms are nonsense.

First, Claude Steele's "stereotype threat" is (almost) pure bunk. From the American Psychological Association:

C. M. Steele and J. Aronson (1995) showed that making race salient when taking a difficult test affected the performance of high-ability African American students, a phenomenon they termed stereotype threat. The authors document that this research is widely misinterpreted in both popular and scholarly publications as showing that eliminating stereotype threat eliminates the African American–White difference in test performance. In fact, scores were statistically adjusted for differences in students' prior SAT performance, and thus, Steele and Aronson's findings actually showed that absent stereotype threat, the two groups differ to the degree that would be expected based on differences in prior SAT scores. The authors caution against interpreting the Steele and Aronson experiment as evidence that stereotype threat is the primary cause of African American–White differences in test performance.

link

Another major criticism of standardized tests is that they don't predict much variance in college GPA. One issue that even many pro-standardized testing people don't consider is that college GPA is not necessarily a good factor to measure any predictor against. The student getting a 3.8 GPA in ethnic studies may have a higher GPA than the student getting a 2.5 GPA in upper division physics courses, but the fact is that the latter student is likely to be a *far* better student than the former. Indeed, even amongst "hard" and "easy" majors there can be a fair amount of variance. Physics, at least at the university I attend, is a far harder major than engineering. I know a number of people who got A's in lower division physics courses (which engineers also take) who are getting C's and D's (with significantly more effort) in upper division physics courses. I would also guess that many social science majors tend to be significantly more difficult than ethnic studies.

Another issue regarding the correlation between standardized test scores and college performance is restriction of range. When there is relatively little variance in test scores at a given university, this relatively small amount of variance in test scores will not necessarily be that useful in predicting college success. However, this does not mean that a large group of people admitted with test scores well below the mean would do well. A useful analogy may be height in basketball. If one were to devise a metric of general basketball performance in the NBA, height would probably not explain an incredibly large amount of the variance (maybe something like 10-20%, depending on the metric). But this does not mean that the NBA could start hiring a bunch of players who are 5'6" and they would all do OK.

I would also add that blacks and whites with the same SAT scores perform roughly the same in college. In fact, the SAT slightly overpredicts black performance in college, and I would suspect the same applies to other 'disadvantaged' groups like Latinos, as well as poor whites and Asians admitted under "top 10%" plans.

Note:If many of these arguments seem similar to those of "dude" in the WM comments thread, it's because I AM "dude."

Edited at 1:27PM 2004-12-22 for clarity

Posted by bb at 01:23 PM | | TrackBack


A must read site!

As GC notes, I am not going to be posting much (though 1-2 times a week seems likely) until the winter starts to thaw out a bit...but I do want GNXP readers to be aware of the excellent site Butterflies and Wheels. The name of the site is drawn from an acrimonious (and intellectually dishonest) attack on Richard Dawkins by philosopher Mary Midgley. Required reading for The Remnant.

Posted by razib at 12:12 PM | | TrackBack

December 21, 2004



Blog-reading recommend

I was listening to C-SPAN this morning when they had some guy on to interview and he kept saying things like "the gap" and "the core" so I became interested. It was Thomas P.M. Barnett and he is a strategic consultant who works for the U.S. Naval War college. He's a professor, but his writings are lucid and a little funny sometimes, and he has a novel way of viewing the world.

Heads up for eBay: it's called Bollywood, not Hollywood. Remember the difference, cause it mostly comes down to how you portray sex.

The story tells you once again that this so-called "clash of civilizations" is really mostly a "clash of gender issues"

That's your "clash of civilizations." Not some grand military struggle between tectonic forces, but a melodrama played out in living rooms.

Update After I published this I noticed someone's previous post disappeared. I did not intend this.

Update II After reading most of his blog I've slightly changed my mind.
I like his writing and he makes a lot of good points, but it's when you congeal them into a cohesive whole that problems start. He denies he is a neo-con, and I kinda believe him - he's worse. If you start putting together his ideas it becomes clear that he wants to transform America into a state funding a giant military and an army of international social workers, and he is not doing it in the best interests of the U.S. (which is something at least the Neo-cons pay lip service to) but instead for the world. I still reccommend him, but from a position of understanding the full spectrum of international policy thinking.

Posted by scottm at 02:32 AM | | TrackBack

December 20, 2004



PC 120: The Multidisciplinary Worlds of Star Trek

I'm cross posting this on GNXP-SciFi but I thought it was relevant to the topics on this blog (e.g. multiculturalism) to post here. Apparently, a university in Decatur, IL is considering offering a course in Star Trek. The idea behind the class?

"This class will boldly go where no one has gone before, as we explore the lore, politics, philosophy, groundbreaking multiculturalism (emphasis added) and historical contexts of the popular science fiction series and phenomenon known as Star Trek," the school's course calendar boasts. "It's a way to discuss a lot of academic topics using Star Trek as a focus or a lens," O'Conner told the Herald & Review, a local paper.

Great. The post-modernists and multiculturalists are poaching on Geek Territory to brainwash a whole new generation.

Posted by scottm at 07:10 PM | | TrackBack


Scary drunks....
Posted by razib at 02:48 PM | | TrackBack


Brazil, kin & race

About 2 years ago a study came out which indicated that there had been some decoupling of ancestry from phenotype in the case of Brazil. That is, a large number of people who were phenotypically "white" had a great deal of African (and Amerindian) ancestry, while a large number of "black" individuals had white ancestry. Though the study is not definitive (Brazil is a large nation, though the sample sizes were decent in my opinion) it does lend support to a large body of ethnological and historical literature which can easily ferret out non-white ancestry among white families which have deep roots in the nation. The authors of the study above suggest that assortative mating over the past few centuries has confounded ancestry in people who display a physical type that is normally associated with a particular region of the world (that is, the relationship between predominant European physical appearence and predominant European ancestry is not clear).

I thought of this study because I recently viewed two movies about Brazil, City of God and Bus 174. Both of these films dealt with crime in Brazil and the color aspect was clear to anyone with eyes. Though there was evidence of racial mixture in the slums, the Brazilian elite could have been southern European. Racism is a reality in Brazil, no matter the "racial democracy" myth propounded for much of the 20th century by the nation's elite. One recent survey found that "black" slum dwellers were twice as likely as "white" slum dwellers to be shot by officers in the line of duty. Making this even more confusing is that he Brazilian police force is traditionally one of the avenues of middle class advancement for non-whites and is 50% "black."

The only insight that I can draw from this is that it all makes mtDNA and NRY studies (or ABDNA's product) a little peculiar, in that people often want to find out about ancestry which has no real relevance in their life. On this blog many South Asians have emailed me about the phylogenetic relationship of their group to others, and I often get a hint that there is a hope that the studies will indicate a close affinity with Europeans. But the reality is, nothing has really changed from one moment to the next, and the proximate features which people use as cues remain the same.

I also wonder about the case of Brazil in the context of the ethno-state. The confounding of ancestry and its decoupling from appearence seems to be a perfect prescription for fooling any proximate psychological kin detection system. Though I am rather shocked by the salience of racial stratification in a society that has, with a straight face, promoted racial democracy and equality, it is notable that the various races in Brazil, whose phenotypes vary a great deal more than say Croatians and Serbs, or Malays and Chinese, have avoided interethnic conflict over the past century (I do not deny the criminal acts of violence). In fact, "black consciousness" is a very new phenomena in Brazil. Though the racial democracy was a blatant falsehood in the face of phenotypic stratification, it was a myth that for many decades prevented the mobilization of blacks to assert their interests as a group (until recently, Carnival in Salvador was an all-white affair, even though the city is 80% black). But, it is also true that many blacks in Brazil probably have a relative who falls in the range of "white" (at least what is white in Brazil), so exclusion did not have the same bite.

Posted by razib at 01:12 PM | | TrackBack


The Tao of Thermodynamics

If you don't have a science background you might want to listen to this BBC programme which discusses the omnipresent 2nd Law of Thermodynamics (my personal recommendation is to perk your ears up when Pete Atkins talks but tune out when John Gribbin pipes up).

Posted by razib at 12:00 PM | | TrackBack


Freedom to offend!

Sikh protesters storm theatre:


HUNDREDS of Sikh protesters stormed a theatre and clashed with police during the performance of a controversial play depicting rape, corruption and murder in a temple.

India? No, Great Britain!

Offensive to religion? Why yes! I listen to the BBC a lot and they've been running interviews with "Sikh spokesmen." These individuals have been saying things like, "freedom of speech does not mean freedom to offend." Or alternatively, "these people must realize that we live in a multicultural society." Or, "one must take into account sensitivity." One spokesperson asserted that "when you have your toes stepped on you have a right to fight back!"

Here is a quote from the article above:


Sewa Singh Mandha, the chairman of the Council of Sikh Gurdwaras, said of the theatre: “They keep saying the playwright has the right to her imagination but these imaginations could harm a community. This play will not help race relations in the city.”

What harm can an imagination inflict!?!? You'd think these people were Post-Modernists who confused text with reality.

I understand that like our northern brethren the Canadians many Europeans "respect" rather than "worship" freedom of speech. Americans are a peculiarly pious folk. So be it. If a woman walks into a drunken fraternity party in a thong bikini, she should not be shocked if she is greeted by obnoxious and possibly threatening behavior, no matter the justice of the matter. But perhaps after any such event the authorities in question should look into dispersing the disruptive and dangerous fraternities and reabsorbing their drunken members into the general student population. Collegial civility might depend upon it (I prefer the retention of attractive women walking around in thongs as the greater benefit in any calculus).

To be less cryptic, if one had to make a Manichean choice between, a) multicultural society, or b) a society that tolerates radical and deviant and offensive visual or verbal dissent from established mores and codes, what would you pick? Yes, many will protest that this is a false choice. Sure, perhaps this is an isolated and abberant event (though Muslims during the Rushdie affair and the recent goings on in the Netherlands are starting to make it a mini-trend), but thousands of pounds of damage and a riot can not simply be dismissed (I'm sure some will disagree with that sentiment too).

Related: Is Christian religious traditionalism going to be the bulwark of the liberties won by the Enlightenment? Don't be so sure:


But the play itself came under fire from Birmingham's Roman Catholic Archbishop, who described it as offensive to all faiths.

In a statement, the Most Rev Vincent Nichols said: "In recent weeks the Sikh community has acted in a reasonable and measured way in representing their deep concerns to the Birmingham Repertory Theatre.

"I regret that the Repertory Theatre, in the interests of the common good, has not been more responsive. Such a deliberate, even if fictional, violation of the sacred place of the Sikh religion demeans the sacred places of every religion."


I smell a new modus vivendi in the air here. Liberal Democrat MP, Dr. Evan Harris, an honorary associate of the National Secular Society speaks for the Enlightenment Remnant:

"While any offence caused by a play or a novel is regrettable, it is vital for free speech and the future of our creative arts that this production is not closed on the basis of protests or intense lobbying.

"These protests and the calls for the end of the nativity display at Madame Tussauds have been fuelled by the Government's ill-judged proposals to ban the incitement of religious hatred.

"It has created a climate whereby any religion's assertion is that their beliefs, leaders, icons and places of worship are protected from criticism, ridicule or parody."


I disagree with Dr. Harris that it is vital that the play not close because of protests or lobbying, it is the right of those who object to engage in peaceful measures to counter what they see as blasphemy. Where the problem occurs is when people move toward acts of violence.

More related: In Defence of Militant Secularism (via Randy). I'm not sure I would call myself a "militant secularist." I would be lying if I said that I live in fear of an established church if that establishment basically meant a few de jure platitudes and a subsidy here or there. I am not in favor of it, but I have a sense of proportionality. What I oppose though rather stridently, and I see in the guise of religious & racial communalism is the revival of pre-modern corporatism, that is, the injunction that individuals must be part of a group, as only groups are treated as atomic autonomous entities. I reject this conception of rights and duties, which I see being resurrected in the identity politics of the Left and sneaking into the West via the communalism of non-Western immigration. I do not expect other human beings to be unmoored, unhinged, unattached and egoistic in their orientation, but I expect those individuals who are communal in orientation to give space to those of us who live the lives of freelancers, who are defined by an unstable fluidity in our relations to the outside world. We will never be a majority (I suspect that cosmopolitans have lower "fitness" in terms of offspring and might emerge as a byproduct of selection forces which actually favor other personality conformations), not even a large minority, but I believe that the intellectual tumult of the past 200 years, for all its folly and error, was in large part a revolt of cosmopolitans against the strictures of communal order and conformity. We are particularly ferocious in our use of the tools that modern civilization offers. The soulless freedom, the liberty that we have won to be apart from corporate entities, is worth preserving (after all, it is in my personal interest!). I am not a utopian, I don't believe that all the world can be university educated and have a greater love of ideas than of cousin, evolutionary psychology tells me that won't be so. My aim is to make the world safe for my people, who are not defined by blood or belief, but a quirky disposition to dance with ideas and explore the bounds of our brains as if that was the end of life itself. I have suggested that my people should not deceive themselves into thinking that all are as they are, that ancient and deep bonds of belief, family and ethnic blood will be worn away by the application of ideas or the distribution of texts or even the compulsion of the gun. But neither should we accept our fate meekly and be bound again by dogmas, rites and rituals, in the straight-jacket of custom and tradition.

Addendum: I think it should be no great surprise that archbishops, CEOs and "community spokemen" should be eager to usher in the new era of "communal sensitivity" and "multiculturalism" and "ethnic harmony." Groups need leaders just as bodies need heads, and in the age of the cartel and guild there was always a big man at the apex of the chain of command. Surely many of these bureaucratic types would be pleased if the cacophony of discord and individualistic choice was suppressed so a new "order" and "harmony" was to arise in the place of the constant shifting of alliances and relative rank fluidity that characterizes the modern mob. The fact is that the super-elites will always be taken care of, and in a relatively authoritarian society power will accrue to them. A community is not an integrated superorganism, it is a social entity which in its day-to-day activities relies on the "guidance" of its leaders. Such creatures surely exist in the form of political leaders, but they do not have sacral status, but are more like hired hands for the mob. Some in the elite, either consciously or subconsciously wish to return to the pre-modern "harmony" of "order." That is why they use terms like "self-hatred" or "traitor" for individuals who seem to be acting in their own interests, because such individuals are disharmonious singletons, and their existence has no meaning outside their group. Yet I submit for some that the betrayl of the self is the cost of submission to the group.

Did I mention I wasn't a conservative?

Posted by razib at 02:18 AM | | TrackBack

December 19, 2004



The origins of phenotypic variation?

Interesting article in PNAS, Molecular origins of rapid and continuous morphological evolution, of which Science News has a good summation. The low-down is that tandem repeat mutations might be crucial in reshaping the morphology of the domestic dog. The Science News article points out that a common conception of dog breeding is that the morphological variation of breeds emerges out of the genetic background of dogs themselves, that is, the ancient ur-canids possessed enough genetic diversity to give rise to the Chihuahua and the Great Dane. These findings instead suggest that a high mutational rate on functional locii is driving the morphological changes of various dog breeds. Wolves and other canids do not diversify into such varied forms probably because functional constraints purify these mutations out of the population. As some have noted, humans, like dogs, also evince a great deal of morphological diversity. It seems plausible that with the rise of culture and diverse lifestyles that humans also removed functional constraints from their morphology, allowing sexual and environmental adaptation work with the mutations that might normally have been been purified.

Addendum: This paper on dog phylogeny offers an interesting point:


Six of 12 ancient Latin American haplotypes are grouped in clade a and include sequences found in dog remains from Bolivia, Peru, and Mexico...No sequences from clade a have been found in samples from over 350 modern dogs (17). The upper bound of a 95% confidence limit for the frequency that sequences from clade a could have in this modern sample and be missed (an observed frequency of zero) is 1.0% (24). Consequently, the absence of clade a sequences from modern dogs suggests an extensive replacement of native American dogs by those introduced by Europeans...genetic analysis of a diverse sample of 19 Mexican hairless dogs (xoloitzcunitle), a distinct ancient breed that has been present in Mexico for over 2000 years (25), only revealed mtDNA sequences previously observed in dogs of Eurasian origin (26). The absence of ancient North and South American dog haplotypes from a large diversity of modern breeds, including the Mexican hairless, illustrates the considerable impact that invading Europeans had on native cultures.

This reiterates the divergence between morphology and ancestry, the morphology of the Mexican hairless dog remains despite the fact that the neutral markers seem to have been replaced by admixture with Eurasian lineages.

Posted by razib at 02:49 PM | | TrackBack


Explanations anyone?

According to David Buss, "the younger woman involved in a love triangle is at a high risk of being killed". If she's usually killed by the older woman, that one's pretty easy to figure out.

So what explains the apparent high risk of pregnant and new mothers being killed, even by those who are not sexual rivals or, in some cases, the father (e.g. Peterson case)?

Posted by jeet at 01:21 PM | | TrackBack