Evidence for Archaic Asian Ancestry on the Human X Chromosome

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Oxford Journals Life Sciences & Mathematics & Physical Sciences 

Authors:

1. Daniel Garrigan*,
2. Zahra Mobasher*,
3. Tesa Severson*,
4. Jason A. Wilder* and
5. Michael F. Hammer*†

1. 
   
   ^*Division of Biotechnology, and ^†Department of EEB, University of Arizona, Tucson

1. E-mail: [email protected].

• Accepted October 4, 2004.

The human RRM2P4 pseudogene has a pattern of nucleotide polymorphism that is unlike any locus published to date. A gene tree constructed from a 2.4-kb fragment of the RRM2P4 locus sequenced in a sample of 41 worldwide humans clearly roots in East Asia and has a most-recent common ancestor approximately 2 Myr before present. The presence of this basal lineage exclusively in Asia results in higher nucleotide diversity among non-Africans than among Africans. A global survey of a single-nucleotide polymorphism that is diagnostic for the basal, Asian lineage in 570 individuals shows that it occurs at frequencies up to 53% in south China, whereas only one of 177 surveyed Africans carries this archaic lineage. We suggest that this ancient lineage is a remnant of introgressive hybridization between expanding anatomically modern humans emerging from Africa and archaic populations in Eurasia.