|
Friday, March 31, 2006
Jane Galt comments on the immigration debate and is convinced by the argument put forth by Bryan Caplan:
When I read this analysis I couldn't help but think that Jane and Bryan are backing the Paul Erlich position in the Erlich-Simon Bet while those who favor rational immigration are backing the Julian Simon side. Now what's odd here is that Erlich, the biologist, lost the bet against Simon, the economist, because he didn't account for the role of technology and now we have two economics bloggers endorsing an analysis which also takes no account of the substitution effect of technology for unskilled labor. Galt and Caplan are arguing that comparative advantage of offering a lifetime subsidy of $89,000 per unskilled immigrant without a high school education will free up labor to more productive uses and that the subsidy for unskilled labor is preferred to the technological substitution that we see in Japan with the rise of robots substituting for unskilled labor. Another point that they neglect to consider in opposing what they call "Eugenic Immigration" are the externalities associated with importing and subsidizing unskilled immigration. Randall Parker goes into some of those externalities in this post. Seeing how they're mooting the question of Eugenic Immigration let me offer another proposition - by opposing an immigration policy Galt and Caplan set up a dynamic to enhance dysgenic trends because the US, with a mean IQ of 100, has the misfortune to be flooded with illegal immigrants with a mean IQ of 90. China, on the other hand, has a substantially homogeneous population with a mean IQ of 105, and they're already instituting neo-eugenic policies. The rise of China is an issue that is already on the rader screens of our economic analysts - now let them factor divergent IQ trends into the mix in order to get a better picture of how the future plays out. What I don't understand is how the net present value of a taxpayer subsidy of almost $1.1 trillion for the 12 million illegals in our midst compares favorably to the labor substitution effect and the economic activity that is generated from the development, manufacture and maintenance of a robotic infrastructure and how supporting a dysgenic trend in an era of lowered social mobility can be considered a winning bet. Robert Samuelson sees the storm clouds on the horizon:
And so does Paul Krugman: (discussed here)
Further, our two econo-bloggers ignore the decline in worker/population ratio from 2000 to 2005: (Bureau of Labor Statistics) White Men: 74.9% to 73.5% White Women: 58.5% to 57.4% White Teens: 50.1% to 40.7% Black Men: 68.4% to 65.2% Black Women: 61.7% to 59.2% Black Teens: 31.2% tp 25.3% and the concomitant rise (20% in 4 years) in Social Security Disability Income recipients from 6,000,000 in 2000 to 7,200,000 in 2004. A good many of these recipients are discouraged workers looking for more reliable incomes than can be found competing against wage depressing illegals. I just don't see how the analysis works to the favor of the Galt-Caplan position, be it an economic or eugenic frame of reference. I wonder if they've read Amy Chua's World on Fire for they seem to be drawing out the long-run blueprint to a US version of a market dominant minority. See this report for more on discouraged workers. Update: Randall Parker has more on this topic.
I just found the useful Freethought Multimedia website, which collects and archives the Internet audio/visual leavings of Richard Dawkins, Steven Pinker, Daniel Dennett, Michael Shermer, and a few related intellectuals. Courtesy of their Pinker section we get the video of Pinker's January talk at the Institute for Jewish Research on the Cochran-Hardy-Harpending paper.
OK...so my notice earlier was an early April fools "joke." Anyway, I apologize to Ron Edgar of the Gene Expression Omnibus, as a concerned reader emailed him. I'll try to think of something more innocuous next time. I should have just made up a fake organization.
My recent post on Sexual Selection mentioned the theory that the 'hairless' skin of humans is due to sexual selection.
After writing this I thought I would check out what is known about the evolution of human body hair. One interesting result is this Royal Society paper by Pagel and Bodmer. Their theory is that hairless skin makes it easier to remove ectoparasites like fleas and ticks, and that humans' loss of body hair was first favoured by natural selection for this reason, then reinforced by sexual selection. [Added: this was a free pdf when I got it a week or two ago, but may now require subscription. For those who want to track it down in a library, the reference is 'A naked ape would have fewer parasites', by Mark Pagel and Walter Bodmer, Proceedings of the Royal Society of London (B) (Suppl.), 270, 2003, pp.S117-119. Or you may still be able to Google up a freebie. Try searching Google Scholar for key words 'Pagel Bodmer naked ape'. When I tried this just now it still gave free access to the full text.] As P & B recognise, it isn't clear whether the advantage of removing crawling parasites like ticks would be offset by an increase in attacks by mosquitoes and other flying pests. Another obvious question is why, if hairless skin makes it easier to remove parasites, man is the only primate to have lost his body hair. Other primates certainly spend a lot of time grooming themselves and each other to remove fleas and ticks. P & B suggest that the loss of body hair was related to the invention of fire and clothing, which would have enabled humans (unlike other primates) to regulate the surrounding temperature. The selective advantage of removing parasites more easily would then not be constrained by the need to retain body hair for warmth at night. Like many hypotheses in human evolution, this one seems vulnerable to the criticism of being a 'Just So Story'. It is attractive, but difficult to prove one way or the other. And the link between the loss of body hair and the use of clothing becomes less plausible when one remembers that most modern hunter-gatherers in tropical countries (Australian aborigines, Bushmen, various pygmies), who are presumably the best model for our out-of-Africa ancestors, traditionally wore little or no clothing. The aborigines are noted for their ability to sleep naked on cold nights. I think that any successful theory for the loss of body hair will need to look more closely at the physiology and genetics of human hair development. Humans are not really hairless at all, but have dense hair everywhere except the palms of the hands and soles of the feet. The appearance of hairlessness depends on the length and fineness of the hair, which is under complex hormonal control in different parts of the body and at different stages of the life cycle. And then there is the puzzle of lanugo, the long hair which grows all over the human fetus but disappears before or shortly after birth. Explain that by sexual selection! [Added: Wikipedia has this to say about lanugo: "Lanugo are hairs that grow on the body to attempt to insulate it because of lack of fat. It is a type of pelage. It occurs on fetuses and it is normal for the unborn baby to consume the hair, which then contributes to the newborn baby's first faeces. Lanugo hair is usually shed and replaced by vellus hair at 36-40 weeks gestation. The presence of lanugo in newborns is a sign of premature birth. It is also a common symptom of serious anorexia nervosa, as the body attempts to insulate itself as body fat is lost." The 'insulation' theory sounds to me like pure guesswork: a fetus in the womb doesn't need insulation! I suppose the anorexia point might appear to support it, until one reflects that there is unlikely to be an evolved response to anorexia: in pre-modern conditions, anyone who got that thin would be doomed.]
Economist Evelyn L. Lehrer states in The New York Times:
You can read a more detailed paper at Lehrer's website. Nothing too weird, and we shouldn't read much into it as there are all sorts of variables that influence the type of person who marries outside their own religion/ethnic group...but, I am struck that most of the marital dissonance between Protestants and Jews also seems to crop up between Catholics and Jew. Genetically it seems clear that Roman Catholicism and Protestantism form a clade with multiple shared derived characters when compared to the outgroup of Judaism, but sociologically in the Catholic-Protestant-Jew trichotomy it is the Protestants that have been the odd ones out in relation to the two white "ethnic"religious groupings. In fact the Jewish and Catholic elites were both united against the WASP establishment until 1950. The diminution of the more crass forms of nativism and a more abstract and intellectual critique of Roman Catholicism non-religious Jews could agree with, and, the subsequent rise of "cultural issues" shattered the Catholic-Jewish alliance which crested during the second heyday of the Klu Klux Klan. But the bigger point might be that the nature of difference is less important than the difference in the first place. Group identity and support which dissolves with an outmarriage might be more important than the multiple stresses introduced by pairwise differences between individuals, as it seems that least ideologically Catholics and Protestants should share more because of their common Christianity.
Thursday, March 30, 2006
We've talked about the French birthrate before, so here is a story out on that topic. Note that France has Europe's second highest birthrate.
Ireland: 1.99 France: 1.90 Norway: 1.81 Sweden 1.75 UK: 1.74 Netherlands: 1.73 Germany: 1.37 Italy: 1.33 Spain: 1.32 Greece: 1.29 To obviate the questions of algebraically challenged readers (lovers of the qualitative query that some of you are), 1.9 = ((white French)/(total)) * fertility + ((non-white French)/(total)) * fertility If you assume that 20% of French women who might have children are non-white (erring on the high side), and you assume that the white French fertility is 1.5, you'd get 3.5 for the non-whites. Just plug and chug possibilities. I don't know the French language literature but my minimal knowledge of Europeans informs me that it is far less strange for French women to have multiple children than it is for Italians (as a contrast), so I don't think the high fertility can be attributable purely to non-white residents.
Wednesday, March 29, 2006
Moebius Stripper responds to a comment left on her blog by a student (not her student though) who wants to set Moebius straight about the grand purpose of education. Some highlights:
I really can't do justice to what Moebius Stripper has written. Go read the whole thing.
In a flashback to the IQ by state hoax, the Times has published a list of IQs by country for most, but not all, European countries. The ranking is attributed to Richard Lynn, without references.
The IQ range of 107 (Germany) to 89 (Serbia) resembles real IQ by US state data. Razib whispers: Beware of British newspapers!!!
You want to know what John Hawks sounds like? He'll be on Radio Open Source tomorrow (there should be a web feed). I talked to David Miller about getting John on the show before he became famous in Slate, so I am going to take a little credit for this. John and Spencer Wells will be "facing off." John, can you ask Spencer to make his email address more accessible? I'm tired of people emailing me and asking about ways to contact him!
Update: John was really amused throughout the whole show. Spencer Wells asked kind of sarcastically (?) if I was "Richard Dawkins." No, I'm not, Spencer :) Thanks to Chris Lydon for giving a shout out to me at the end of the show. Also, Brendan said that both John and Spencer were on the show at my suggestion, so that's cool, I guess I'm a "scientific activist" of sorts now?
Delayed Brain Development Associated with Greater Intelligence
posted by Razib @ 3/29/2006 12:25:00 PM 
 
A few days ago I received an email from a reader asking me about the possibility for differentiation of populations because of the postgenomic era, eg., the use of multiple markers to achieve separability. They brought up the near disjoint character of the Duffy antigens between Europeans and Africans (ergo, its historical utility in calculating white admixture into the African American population). One thing I offered is that if a derived allele is near fixation (near 100% in group X), then it will likely be characterized by high frequencies in many other groups and one might find it more worthwhile to search for populations that remain in the ancestral state. In other words, resistence to the acquisition of beneficial alleles by particular local populations, or, more likely, their insulation because of time and space from the region of the origin of a current selective sweep, will be more common than the detection of locally stable clusters of high derived allele frequencies. My hunch is that highly beneficial alleles that emerge within a population will most likely be beneficial in other populations and deme-to-deme gene flow is a powerful force. For example, I think something like lactose tolerance is relatively common, an allele which swept through distinct and varied populations in Eurasia where cattle culture was feasible. This doesn't people separability is not possible or plausible, obviously Risch's work falsifies that manifestly, rather, I think that the pairwise comparison of nearly disjoint allele frequencies across populations is going to be a lot less interesting than the richly complex relief of gradients which will track geography and history ways we don't even understand yet.
Crooked Timber has done a web seminar on Chris Mooney's Republican War on Science
I was especially happy to see John Holbo's piece, "Mooney Minus the Polemic?", which points out the exception of science friendly libertarians and their own disdain for the liberal abuses of science: [hypothetical libertarian soliloquy:] Liberals are the ones who are always refusing to look at the facts. Look what they did to poor Larry Summers because he tried to speak truth to power! They buried their heads in the sand when The Bell Curve came out! Whimpering "frankenfood." Postmodern nonsense! What the academy needs is a return to reason! The comments thread of "The Stars and Stripes Down to Earth (posted for Daniel Davies by HF)" includes some suggestions re: a Democratic war on science along the same lines. Overall, Chris [link to his site at ScienceBlogs] does a good job of handling the criticism.
Monday, March 27, 2006
Check it, got this note from Adam Bly of Seed:
If BusinessWeek is reading my other blog, shouldn't you be? :)
Sunday, March 26, 2006
This whole conversion story in Afghanistan has been in the news recently. The Christian Science Monitor attempts to put the issue of conversion from Islam to another religion in an international perspective. Most readers of this weblog know that I am cautious about making large generalizations without qualifications, but I will offer that as a civilization, "Dar-al-Islam," has particular issues with conversion when set against "Hindu" or "Christian" civilization. Though the difference is quantitative, not qualitative, some facts are so naked that caveats can not truly cover up the shame.
There are "Muslim" nations where conversion to other religions is socially acceptable. Albania and Indonesia are two such cases. In Albania the dereligionization of Communist period has been followed by a feeding frenzy of religious activity as Muslim and Christian groups have entered the country and turned it into a rational choice competitive marketplace of memes. I am to understand the current issue of First Things has an article by Stephen Schwartz where he notes that Muslim clerics in Albania do not begrudge conversions to Christianity (specifically, Roman Catholicism, another one of Albania's traditional religions, as evidenced by Mother Theresa). In Indonesia after the 1960s there were widespread conversions to Hinduism by Communism sympathetic nominal Muslims (whole villages sometimes converted due to animus against orthodox santri Muslim landlords and their right-wing thugs), and to this day there tends to be acceptable religious flux in this nation as Christians, Hindus and Muslims make conversions from each other's camp. In Africa there are also many conversions from Islam to Christianity, I recall Pat Robertson bragging that thousands of members of a tribe that was traditionally Muslim was converted to Christianity in Burkina Faso thanks to the activities of missionaries. Nevertheless in wide swaths of the Muslim world standard sharia injunctions against conversion away from Islam are normative. For example, in Pakistan and Bangladesh Christian missionaries have targeted the Hindu minorities because the Muslim majority will not tolerate evangelization. The same pattern can be found in Malaysia, where Christians proslyetize amongst Buddhists, Chinese folk religionists and Hindus, but avoid the Muslims for fear of political retribution. I also recall that back in the 1990s Go Chok Tong warned Christian fundamentalists about upsetting the religious balance of the city-state in part because of anger from the Muslim Malay minority. How to interpret this? First, one must note that horror at conversion to another religion has never been limited to Islam, one only need to look at the Hebrew Bible, or injunctions against Jews owning Christian slaves and statues against Judaizing to know that other branches of the Abrahamic family tree have been ill at ease with individual defections of creed. The long history of interaction between pagan and Christian in Europe between the 4th and 12th centuries was one of transition from the former to the latter, in large part because reversion from the latter to the former was rarely accepted. Within bounds Christians still are not especially comfortable with conversion away from their own flock, the "anti-cult" movements on the fundamentalist fringe of American Christianity are often focused on critiquing New Religious Movements which are perceived as a missionary threat bent on "stealing" their youth (in the course of being instruments of Satan of course). In The Future of Religion Rodney Stark and William Bainbridge report data which shows that Americans who are most supportive of the Great Commission are also the least favorable toward allowing non-Christian missionaries to freely operate within the United States (Seventh Day Adventists were an exception). I also recall years back when John Paul II proudly told Indians that the Catholic Church would not turn aside from its missionary program in South Asia, this, at the same time the Church was vociferously objected to the intrusion of evangelical Protestants into Latin America (Roman Catholics might fairly contend that the analogy does not work because the latter case was "sheep stealing," but of course my understanding is that Catholicism has always been a missionary religion in Protestant lands where such activity is feasible). There are several issues here. First, intolerance and disgruntlement at defection from group identity is normal. The recent flair ups against Christian missionaries in India and the occassional "Satanism" hysteria in the United States show that it lurks under the surface in cultures where conversion is accepted and protected. I think it is to some extent an emergent property of human "groupishness," of "doing what your neighbor does." In some societies, like the United States conversion from various religions to others is common enough that the social stress is limited to an interpersonal level, community censure is simply too weak to be powerful. There are exceptions, for example I have heard of Mormons who leave the religion not being able to live a normal life in parts of southeastern Idaho because day-to-day interaction is not possible due to ostracism. But in most of the United States the intersection between religious pluralism and social mobility results in a cocktail where "church shopping" is common. Other nations are not like this. And to some extent the United States is an aberration, the only real analogy being countries like Albania where traditional religious institutions have been totally demolished and have not had the time to recover and monopolize the social space they once held. Most nations with long histories do have "established" churches, whether via custom or law. Russia has the Orthodox Church. Sweden has the Lutheran Church. Malays are Muslim. Spaniards are Roman Catholic. Jews are, well, Jews. These are what I term "cartel cultures" where higher order religious goods & services are monopolized by one particular umbrella institution. Some of these cultures have sizable secular minorities who no longer participate in the transactions mediated by the monopoly (communal prayer, mass, etc.), but there is little competition from other umbrella institutions. In cultures like Russia the monopoly religious institution is not just a religious institution, it is an organic and necessary part of the communal culture. This inseparability means that defection from the Russian Orthodox Church toward a Protestant Christianity is far more threatening than simply lapsing in practice. This might explain the phenomenon of Jews and Muslims in Christian cultures expressing more hostility toward converts to Christianity from their own ranks as opposed to the non-religious who reject the creedal points but do not replace them with an alternative set of beliefs. Unbelief does not necessarily imply rejection of the community, but alternative beliefs do. The cartel system has been the modus vivendi for many cultures over the past few thousand years. The millet system under the Ottomans was one of the more explicit manifestations of this, each religious leader was responsible for his own community. Elsewhere, rabbis in much of Eastern Europe became princes of their people, and where Roman Catholics were a minority they organized their own counter-cultural institutions against the Protestant majority. In The Netherlands the "pillar" system reflected the self-organization of Catholics, Protestants and the unaffiliated. Of course this system isn't etched into our cultural DNA. Small-scale peoples do not construct doctrines and institutional churches which promote and execute creeds and practices. Nevertheless, the basic tools were already in place, ostracism and other social pressures already had developed to an advanced stage to enforce group conformity and coherence. They were simple scaled up, with an extra layer of rationalistic sophistication (theology, doctrine, etc.) wielded by a specialist class (clerisy) sitting atop the system. Where does this leave us? In regards to Islam as it is practiced and enforced in much of the Middle East and South Asia it seems that the cultural form is simply a refined expression of a common stable state. Familial, clan and ethnic honor are intertwined with religious profession in a set of interlocking contingent norms and practices with serve as cultural boundaries. In some parts of the Muslim world, in the Balkans, Africa and parts of Southeast Asia the magnitude is attenuated and there is more give and take with other cultural communities. Similarly, in India and and in much of Europe conversion from one religion to another is legal, but subject to social costs and strain. In the United States and South Korea and in parts of Africa conversion is so common, and switching so ubiquitous, and the pace of economic and social development so rapid, that the normal modus vivendi has been overturned and religion has become, to some extent, McChurch. It has been torn away from custom and tradition and stability of generations, and into more ad hoc fluid organizations which serve individualized needs and preferences. This is important because to some extent in international contexts there seems to be tendency to frame the debate as if the religiously fluid situation in the United States is the norm throughout the world, or that it should be. George W. Bush is a Methodist, his father is an Episcopalian, while his brother converted to Roman Catholicism. Karl Rove is not religious. Marvin Olasky, the father of "compassionate conservatism," is a convert to evangelical Christianity from Judaism. The point is that George W. Bush's experience has primed to see conversion as only a personal choice, when in most of the world it is a profoundly transgressive act that is a rebuke to kith and kin. The recent problems caused by South Korean Christian missionaries in Iraq also point to the same mentality, taking for granted religious conversion as a normal part of life when it isn't. Some of the Christian Churches of the Middle East have a nearly 2,000 year old history, so they are particularly affronted when evangelicals from the United States attempt to "convert" their youth. Myself, I think the instability of the new world is a byproduct of radical individualism. I like this, I enjoy the choice that volition it introduces into the self-creation of individuals. But, I do not think that its future ascendence is going to be without bumps and rocky patches. And, I don't think it is "normal" in any straightforward sense of the word, humans are a social animal, and the customs and traditions of almost all traditions rebels against the radical choice which enslaves the culture to the whim of the individual.
I need an estimate of the fraction of selected variants that involve an amino acid change, as opposed to noncoding changes in promoters and enhancers and such. Something for mammals would do. Can anyone find one?
Seems like a Jersey principal was instructed to cheat on state tests.
Good thing the cheater was caught, so that this thing won't ever happen again. ADDENDUM: From the Wikipedia article on Camden:
La Griffe has a nifty solution all ready to go for just this kind of situation.
Nothing big enough for its own post, just a bunch of things that caught my attention:
PLoS Genetics: AVPR1a and SLC6A4 Gene Polymorphisms Are Associated with Creative Dance Performance We therefore hypothesize that the association between AVPR1a and SLC6A4 reflects the social communication, courtship, and spiritual facets of the dancing phenotype rather than other aspects of this complex phenotype, such as sensorimotor integration. PLoS Medicine: Are Racial and Ethnic Minorities Less Willing to Participate in Health Research? Nope. TSC: The Stone Age Trinity wherein a libertarian realizes that humans have an egalitarian instincts which will get in the way of a libertarian society. TNR: Blue State Blues -- Criticizing "red state snobbery", Jonathan Chait writes "I wonder if Wolfe and his fellow travelers realize how much their mau-mauing of blue staters is, well, Maoist." -- Ironic new meaning of "Red state".
Saturday, March 25, 2006
A paper in PLoS Genetics, Assumption-Free Estimation of Heritability from Genome-Wide Identity-by-Descent Sharing between Full Siblings, describes a way to determine heritability using actual genotypes in leiu of estimated kinship coefficients.
From the synopsis: Quantitative geneticists attempt to understand variation between individuals within a population for traits such as height in humans and the number of bristles in fruit flies. This has been traditionally done by partitioning the variation in underlying sources due to genetic and environmental factors, using the observed amount of variation between and within families. A problem with this approach is that one can never be sure that the estimates are correct, because nature and nurture can be confounded without one knowing it. The authors got around this problem by comparing the similarity between relatives as a function of the exact proportion of genes that they have in common, looking only within families. While children inherit more or less exactly half of their genomes from each parent (and thus -- usually -- have a coefficient of kinship of 1/2) due to the mechanism of two hapolid genomes combining at feritilization, for full siblings the actual coefficient is merely distributed around a mean of about 1/2. Due to chance segregation, some siblings have an actual relatedness which is greater than 1/2 and others less than 1/2. Here's the actual distribution of relatedness that they measure:  The rest of the synopsis: Using this approach, the authors estimated the amount of total variation for height in humans that is due to genetic factors from 3,375 sibling pairs. For each pair, the authors estimated the proportion of genes that they share from DNA markers. It was found that about 80% of the total variation can be explained by genetic factors, close to results that are obtained from classical studies. This study provides the first validation of an estimate of genetic variation by using a source of information that is free from nature–nurture assumptions. They get a h^2 of 0.8. My reading of there paper is that this may be an underestimate: We have ignored the contribution of the sex chromosomes to genome-wide IBD. In humans, the X chromosome accounts for 4% of genes and 5% of physical length [29]. If all chromosomes account for genetic variation in proportion to the number of genes or physical length, then our estimate of heritability will be biased downwards by about 4% to 5%. This is a very important paper for several reasons. First, it should permit the verification of heritability coefficients for phenotypes like IQ where there has been some dispute. Second, it will permit the estimation of heritability in tandem with mapping projects that have sibs. I imagine there are already suitable datasets out there waiting to be mined.
Some horses are fast, and some horses are Secretariat. After the great horse's death an autopsy revealed that his heart was about three times as big as it should have been, certainly a prescription for early mortality. The greatest racer of them all seems likely to have been a biological freak, where some developmental or genetic quirk allowed him to pound away with a macro-heart. None of Secretariat's offspring replicated his magnificence. This makes sense, a classic case of regression to the mean. If one assumes that Secretariat's massive but healthy heart was the byproduct of an exceedingly rare combination of beneficial genes, then sexual reproduction will likely break apart such favorable variations.
But there could be other reasons that Secretariat's offsprings weren't quite what he was, circulatory physiology aside. A new study has just come out which concludes that mitochondrial genetics might play a crucial role in the respiratory performance of a horse.
Mitochondria are of course only passed through the female line, so none of Secretariat's offspring would have had his particular respiratory engine. You can read the full paper on the site of the company that is sponsoring this research. I can't help but wonder if some Arab sheikh knew this all along....
CNN has a short feature on the "Muslim Madonna," Deeyah, you can see the video here.
Addendum: There is a controversy about the veracity of this young woman's claims. Prior facts are important here in judging the likelihood of various scenarios. My own view is that this is self-promotion leveraging upon some real background issues.
Friday, March 24, 2006
The fallacy of "ontogeny recapitulates phylogeny" is one of the truisms of our age. I am trying to think of a nice way to get across another idea, that phylogeny does not necessarily imply morphology (or phenotype). In other words, this is the inverse of convergent evolution, where phylogenetically distant kinds exhibit similar morphology because of canalization via the same selective forces in concert with structural constraints. Here I am speaking toward cases where phylogenetically close organisms seem to exhibit extremely differentiated morphologies. Consider the relationship between chimpanzees, humans and gorillas. One line of phylogenetic research implies that gorillas are an "outgroup" to the chimpanzee-human clade, but, to the homocentric mind it seems that our own species exhibits a range of morphological features which set us apart as particularly distinct from our anthropoid cousins. In other words, morphologically one could argue that chimpanzees and gorillas form a phenetic clade,1 while chimpanzees and humans form a phylogenetic clade. Most long time readers of GNXP know the "back story" to this post. 3 years ago I posted an email from Henry Harpending where he offered that in some cases some human populations exhibit greater phylogenetic similarity (neutral loci) than one would suspect based on physical ins |
