A set of beneficial genes carried by African emigrants, perhaps ones that assisted in childbearing, brought a selective advantage that eventually blotted out the signature of some archaic genes.

• 哈彭丁为此提出解释，例如迁离家园的非洲人带来一组有益的基因可造成某种优势（也许是顺利分娩），到最后把某些古代人种基因的特性遮盖掉了。