Monday 7 January 2008
The roles of fossil human populations in the origin of modern humans have been enigmatic. Earlier (archaic) human populations were biologically similar and were in recurrent temporal and geographic contact, making interbreeding between ancient populations likely.
Regardless of the taxonomic status of these populations, adaptive alleles may have introgressed from archaic populations into modern humans.
When an introgressed archaic allele has a selective advantage, even rare interbreeding can lead to its spread or fixation in later human populations.
Several genetic loci are candidates for such introgression, including microcephalin, a gene influencing brain development.
Hawks J, Cochran G, Harpending HC, Lahn BT.A genetic legacy from archaic Homo.Trends Genet. 2008 Jan;24(1):19-23. Epub 2007 Dec 3. PMID: 18063439 [PubMed - in process]