PubMed Health⌕ Search

Biomedical subjects

Jiujin Xu

Publications and source records attributed to Jiujin Xu.

5 recordsLinked to original sources

Male demography in East Asia: a north-south contrast in human population expansion times.

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 increase in number only when a warmer and more stable climate led to more plentiful plant resources such as tubers.

Asian People↗

Recent spread of a Y-chromosomal lineage in northern China and Mongolia.

We have identified a Y-chromosomal lineage that is unusually frequent in northeastern China and Mongolia, in which a haplotype cluster defined by 15 Y short tandem repeats was carried by approximately 3.3% of the males sampled from East Asia. The most recent common ancestor of this lineage lived 590 +/- 340 years ago (mean +/- SD), and it was detected in Mongolians and six Chinese minority populations. We suggest that the lineage was spread by Qing Dynasty (1644-1912) nobility, who were a privileged elite sharing patrilineal descent from Giocangga (died 1582), the grandfather of Manchu leader Nurhaci, and whose documented members formed approximately 0.4% of the minority population by the end of the dynasty.

Alleles↗

The genetic legacy of the Mongols.

We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: approximately 8% of the men in this region carry it, and it thus makes up approximately 0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia approximately 1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior.

Asian People↗