03 March 2011

Short Takes

* Spinal fluid biomarkers can distinguish between people suffering from Lyme disease (a tick carried infectious agent), Chronic Fatigue Syndrome (probably a viral condition with a long latency period), and uninfected individuals. This is important first, because Lyme disease and Chronic Fatigue Syndrome can present with similar symptoms, and second, because diagnosing Chronic Fatigue Syndrome and even finding ways for sufferers to convince people that they have a genuine biologically caused disease rather than simply being lazy, is a major challenge.

* The Kalash people in a remote part of the Hindu Kush Mountain range are one of the most genetically distinct populations in the world. When one has a computer break the world's autosomal genetics into the most distinct possible seven clusters, the clusters that you get are: African, European, South Asian, East Asian, Papuan, indigenous American and Kalash.

Their Y-DNA haplogroups (from a sample of about 43 people) are as follows:
L3a 22.7% (most common in Pakistan)
H1* 20.5% (most common in South Asia)
R1a 18.2% (most common in Eastern Europe and South Asia)
G 18.2% (most common in Southern Europe, Anatolia, Druze, Brahui and Pashtuns)
J2 9.1% (most common in Anatolia and where Indo-Europeans have had an impact)
R* 6.8% (most common in Thailand, Indonesia, the Phillipines and Australian aborigines)
R1* 2.3% (most common in indigenous Americans)
L* 2.3%. (most common in South Asia)

Their mtDNA haplogroups (from a sample of 44 people) are as follows:
pre-HV 22.7% (most common in Socotri, North Africa, Iran and Arabia)
HV* 4.5%
H 4.5% (the modal haplogroup of Europe)
U2e 15.9% (most common in South Asia)
U4 34.1% (most common in Central Asia)
U7 2.3% (most common in South Asia)
J1 2.3%
J2 9.1%
T* 4.5%

They speak a language from the Dardic branch of the Indo-European family (one of the more basal of the Indo-Iranian part of the late language family), and practice a polytheistic religion.

They are between areas that areas typically Central Asian and areas that are typically South Asian in genetic makeup. Their traditions place them as a lost contingent of Alexander the Great's army, but given their uniparental markers, the genetic makeup, their particularly contingent would have had to have picked up members mostly from the area from Anatolia to the Hindu Kush. Their Dardic language is also an anomaly for an isolated community claiming to descend from the Greeks, they lack common distinctively Greek uniparental markers, and their religion is close to Hinduism than it is to Greek pantheistic beliefs. An origin a millennium or two earlier (if not much more ancient) would seem to be a better fit for the facts.

Given their autosomal makeup, any new arrivals in the region from somewhere would have had to either admixed substantially with a relict population that was largely wiped out or overwhelmed genetically elsewhere such as Europe and Central Asia's pre-Neolithic hunter-gatherers, or South Asian hunter-gatherer populations disrupted by Munda, Dravidian, and Indo-Aryan populations respectively. Alternately, they might have undergone significant selectively driven evolution analogous to that found in Tibetans as a result of living at high altitudes. The case for incorporation of a relict Central Asian hunter-gatherer population is most strongly supported by the modal mtDNA haplogroup U4, which was one of the second most common types found in ancient DNA from Central Asian hunter-gatherers.

* There are a couple of kinds of invasive ants that have an unusual reproductive system. Future queens are clones of the current queen. Future drones (reproducing males) are clones of their fathers. Workers, who do not reproduce, have a mix of the queen and the drone's genes similar to that of ordinary sexually reproducing animals. (I'll try to find a reference later).

* As a thought experiment, it is interesting to consider would it would look like to have a society where a human or near human species with reproduction system in which only half of women had children, but they had an average of four and a half surviving descendants, assuring the replacement of the species. There are several different permutations of this that would be possible. Half of children could be gay. Half of the children could be infertile (perhaps clones of their same sex parent, or perhaps surgically or chemically neutered). Half of females could be in "harems" like those of alpha dominated gorillas or lions, and only alphas might have the pheromones necessary to trigger reproduction. One imagines that such a society might resemble the Byzantine courts.

Alternately, one could imagine a society where half the women were in a social class that averaged surviving three children, while the other half the women were in a social class that average one surviving child. A study of the vital statistic of a Bronze Age society in Spain based on its burials and the inferred diets of the dead, which showed a minority elite with a high protein diet surviving at much greater rates than a "middle class" (perhaps soldiers) or an even more deprived underclass (perhaps servants or slaves), with this kind of demographics.

* There is a tendency in Anglo-American political economy to imagine a society with strong property rights and weak governments as a "state of nature" against which political action should be measured. But, this sense is to a great extent ahistorical, particularly in farming and more urbanized societies. The oldest Minoan Linear A script is preserves administrative records of ration distribution systems, basically welfare states, that had strong parallels in Sumeria, Egypt, the Hebrew Bible and Rome - i.e. all of the major civilizations of the Mediterranean of the Copper Age, Bronze Age and Iron Age, and arguably via feudal societies into to the Middle Ages. There also seems to be evidence that these were command economies in which soldiers played an integral economic part, perhaps along the lines of the large role played by military owned enterprises in the civilian economies of modern Egypt and China. Likewise, fedual societies were basically agrarian economies run on a military footing with involuntary serf labor.

Decentralized market driven economies with contract rights and private property as an important organizing principle doesn't really emerge as the predominant component of the economy until after the Middle Ages end in Europe.

* NPR made some notable observations about the Middle Eastern oil states that are experiencing revolutions at the moment. Generally speaking, these states don't impose significant taxes on non-petroleum activities. Oil money funds government operations including strong military forces and a significant welfare state. This helps explain why the oil rich states of the Middle East have managed to survive while being so undemocratic. Historically, constitutional monarchy and republican government in cases like Rome, England and France have their roots in the need of a monarch to obtain consent of representatives of people who were going to be required to pay taxes to support the state. Taxes are the price of democracy.

* Some of the dates assigned to remains used to argue for an early presence of modern humans in Europe engaged in relatively primative economic industry have been revised upon further examination to more recent dates. Remains previously touted as more than 30,000 years old, which had "long been considered to be the earliest evidence of the remains of modern Homo sapiens anywhere in Europe" in Southern France and Southwest Germany have been re-examined within the last decade and determined to have actually been less than 10,000 years old.

This also influences how one conceptualizes the Chatelperronian lithic industry in Europe, which in turn relates to how smart we think the Neanderthals were. The prior and more primative Mousterian industry is clearly associated with Neanderthals. The industry that follows the Chatelperronian is associated clearly with modern humans. The Chatelperronian has traditionally been associated with Neanderthals as well, but some researchers have argued for it as "an independent development by Neanderthals (d'Errico et al. 1998)" while others "see the Chatelperronian as the result of the acculturation of Neanderthals by modern humans (Mellars 2005)." People care, because if the Chatelperronian was an independent Neanderthal invention, then maybe they were pretty smart and advancing their technology just as the humans did when climate conditions improved. In contrast, the opposite extreme would be to argue that admixture of modern human traits into Neanderthal populations is the only reason that they were able to innovate as much as they did even in the relatively primate Chatelperronian era. Between the two extremes is the possibility that the Neanderthals were capable of mimicing modern human Upper Paleolithic lithic industries, even if they would have been hard put to develop it themselves.

John Hawks, approaching the same underlying question of Neanderthal intelligence from another angle wonders if the ability of people born blind to repurpose their visual centers for language doesn't suggest that language is less hard wired, and hence, less likely to require genetic evolution, than has been often assumed: "Kaschube and colleagues showed that the apparent developmental robusticity of the visual cortex could be maintained by simple rules of self-organization. It doesn't take specialized genetic control to create a visual cortex, it just takes information structured in the right way to flip a few genetic triggers" and the right kind of environmental exposures. As he explains:

The blind subjects tell us that the ground for language processing is almost as fertile elsewhere in the cortex. Many brain areas have the genetic equipment to recruit and organize neurons into useful circuits for language processing. Language development is developmentally robust because it can rely on a rich language environment, not because of genetic standardization. The basic problems of language evolution must be explained by showing how robust language communities emerged. I don't preclude genetics, far from it -- weaker language environments may have become stronger because of evolutionary change. But that evolution must have been substantially domain-general, because language processing is not specifically canalized by genetics.

I like this scenario because it means we shouldn't be looking for lots of language-specific genetic changes in the last few hundred thousand years. The Neandertal genome suggests that there may not have been any at all.

My second speculation: If the language environment determines the instantiation of language processing, then brains must be substantially different in the way they process language. Children experience different language environments -- not only different languages, but different microenvironments within language communities. Only strong genetic controls could canalize brains despite the differences in their language environments. In brains where language processing emerges readily in the visual cortex, genetic controls cannot possibly synchronize brains in the face of environmental variation.


* A case is being made that the strong genetic discontinuity between South Asia and Southeast Asia, despite the lack of an obviously inpenetrable geographic barrier is attributable to the effects of the Toba volcano erruption, that while not wiping out the modern human population in South Asia, did seriously disrupt and reshape it:

Oppenheimer . . . [suggests] that the prolonged ash cloud could have devastated all or most of India, especially both M and N related populations in the east and south, closest to the volcano. He hypothesizes that this area could then have been repopulated by M dominated groups immigrating from the east, who might then have spread, in a cline, to the rest of the subcontinent, while N-related groups to the west could have repopulated India from that region. This could have left India populated by more recent M and N hapolotypes than those found farther east[.]


He also associates this event with the distribution of tone languages which are found in Africa, "scattered among so many indigenous peoples of Southeast Asia, southern China, Indonesia, Taiwan, the Philippines, and Melanesia" and in "northernmost reaches of the Indus valley . . . "would have been a likely spot where a branch of the Out of Africa migrants, who could have broken from the main group to travel north along the banks of the Indus, might have been able to survive the effects of Toba with their African traditions more or less intact. If tone language was part of their HMC inheritance, then that could explain the prevalence of tone language in this area today." Suggested musical linkages that might be legacies of this connection are discussed here.

1 comment:

Stan Morris said...

Utopias aren't as interest in as dystopias are. No conflict