Genetic map of asian population
a study of SNPs has determined that the entire asian population came from a single migration from south asia.
Results showed that individuals coming from the same region, or speaking the same language had great genetic similarities, and Asia was populated through a single migration from the south.
“It seems likely from our data that they entered South East Asia first – making these populations older [and therefore more diverse],” a leading member of the consortium Edison Liu said.
that ppl from the same region or speaking the same language should tend to share great genetic similarities should surprise no one. this next part was interesting to me tho.
“So although the Chinese population is very large, it has less variation than the smaller number of individuals living in South East Asia, because the Chinese expansion occurred very recently, following the development of rice agriculture – within only the last 10,000 years.”
i’m not sure if i would have expected that. china has an array of different dialects and ethnicities, and i would have thought that would contribute to diversity. apparently, it doesn’t. at least not much genetically.
finally, one of the researchers says the findings were a “reassuring social message,” which “robbed racism of much biological support.” that’s a nice sentiment, but is it really that assuring? they’ve found that within a rather short amount of time (geologically), 10,000 years, a number of groups had diverged significantly enough that scientists could easily guess their region of origin or their spoken language. yes, we all came from one population, but now apparently we’re demonstrably different genetically. hmm. i’m not feeling especially reaassured.
UPDATE: here’s a graph from that study i saw on gnxp.
1 Comment »
RSS feed for comments on this post. TrackBack URL
I tend to rambling, but it’s not too surprising I think when you take cultural history into account. 10,000 years is about all of recorded and rumored chinese history, confirmed or legendary, and maps of chinese imperial control tend to fluxuate directly over the same area. With a consistent pattern of Sinification/standardization by the successive imperial dynasties, and especially in later time periods which has already lasted for millenia, you get melting pot syndrome between the different ethnic groups (at least in central-eastern china) that basically have intermarried and lost genetic cohesion, such that you still have general facial patterns by region but the genetic marker materials are spread all over the place.
Even with millenia-long sinification, it also helps that the main chinese population has also bottlenecked several times during some of the more famous civil war periods. The most significant I can think of is the Three Kingdoms Period to the Jin period. ref. Wikipedia because I’m too lazy to go find a real source, but between the end of the 400 year Han dynasty and the Jin Dynasty reunification the population went from 50 million to 16 million. Even discounting differences in census reach and technology, that’s a huge percentage loss in genetic diversity over roughly a hundred years. The Spring and Autumn Period and Warring States period was another period of constant war, the Song-Yuan conflicts, famines or plagues that coincided with the collapse of some dynasties, the various rebellions through the centuries, including the Taiping Rebellion.
With the chinese core territories generally secure from an influx of foreign genetic material (especially when you get conquerer groups like the Yuan and Manchu generally keeping to themselves in terms of marriage), I feel like it’s quite normal that “China,” notwithstanding its territorial assimilation of former vassal groups in the last century, has relatively stable genetic material as a whole.
The same thing happens to non-nomadic asian states in general. Except for a few shortlived imperial forays into the southern area from the Mongols and Chinese, I can’t think of much displacement in the population, between the khmer and viet and various ethnic kingdoms. Korea has maintained a rather distinct genetic profile, as well as the Japanese for the same reasons. Besides trade, there’s not much real migration between them and the rest of asia. Japan was snugly fit on a bunch of sea-islands, and Korea was either being invaded or propped up by China, Japan, or trying to maintain its own sovereignty by playing everyone off each other, but otherwise essentially staying right where they were in the Korean Peninsula, without the ability to expand outside.