Where did Asians migrate from?
A new study shows all Asians probably originated from Southeast Asia and migrated northward, indicating Japanese landed in their present location via the Korean peninsula.
In a paper titled “Mapping Human Genetic Diversity in Asia,” published online in Science on Dec 10, members of the Human Genome Organization`s Pan-Asian SNP Consortium reported on the genetic patterns of 1,923 individuals from 73 Asian populations, including 90 Koreans.
The team of researchers – from 10 Asian countries as well as investigators from the United States – reported a clear genetic diversity arising from northern to southern latitudes, suggesting there was one major inflow of human migration into Asia arising from Southeast Asia. Previously, it was thought that there was a multiple inflow from both southern and northern routes.
This is the first time that studies on human genetic diversities have extended research to Southeast Asian and East Asian populations.
The analyses proposed a model in which ancestors of today`s Asian populations arrived first in India before migrating to Thailand, Malaysia, Indonesia, and the Philippines. From there, it suggested groups traveled north, mixing with the populations already living in these regions.
This accordingly suggested the ancestors of Koreans, Chinese and Japanese to be the latest to settle in East Asia. The study also revealed no meaningful genetic differences between the three ethnic groups, which together make up 1.5 billion people.
“On the basis of variation at a large number of independent SNPs, we observed that there is substantial genetic proximity of Southeast Asian and East Asian populations,” the researchers wrote.
“More than 90 percent of East Asian haplotypes could be found in either Southeast Asian or Central-South Asian populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50 percent of EA haplotypes were found in SEA only and 5 percent were found in CSA only, indicating that SEA was a major geographic source of EA populations,” the study stated.
Scientists also disclosed the corresponding relationship between genetic ancestry and language groups.
“Our results show that genetic ancestry is strongly correlated with linguistic affiliations as well as geography. Most populations show relatedness within ethnic/linguistic groups, despite prevalent gene flow among populations,” they wrote.
These insights were noted by researchers to have important implications for the study of genetics and disease, and for both interpreting past and designing future human migratory patterns.
HUGO President Edison Liu, also the executive director of the Genome Institute of Singapore, in a statement released yesterday, referred to the study as “a milestone not only in the science that emerged, but also the consortium that was formed.
“Ten Asian countries came together in the spirit of solidarity to understand how we were related as people, and we finished with a truly Asian scientific community. We overcame shortage of funds and diverse operational constraints through partnerships, good will, and cultural sensitivity.”
The next goal was said to expand this collaboration to all of Asia, including Central Asia and Polynesian Islands, with more detail in genomic analyses and structural variations.
(jyan2787@googlemail.com)
By An Ji-yoon
2009.12.12
Solpeer6's Blog 
Leave a comment