Genetics. 2006 Feb 19; [Epub ahead of print]
Male demography in East Asia: a north-south contrast in human population expansion times.
Y. Xue et al.
The human population has increased greatly in size in the last 100,000 years, but the initial stimuli to growth, the times when expansion started, and their variation between different parts of the world are poorly understood. We have investigated male demography in East Asia, applying a Bayesian full-likelihood analysis to data from 988 men representing 27 populations from China, Mongolia, Korea and Japan typed with 45 binary and 16 STR markers from the Y chromosome. According to our analysis, the northern populations examined all started to expand in number between 34 (18-68) and 22 (12-39) thousand years ago (KYA), before the Last Glacial Maximum at 21-18 KYA, while the southern populations all started to expand between 18 (6-47) and 12 (1-45) KYA, but then grew faster. We suggest that the northern populations expanded earlier because they could exploit the abundant megafauna of the 'Mammoth Steppe', while the southern populations could only increase in number when a warmer and more stable climate led to more plentiful plant resources such as tubers.