Evaluating signatures of sex-specific processes in the human genome

Abstract

Comparing levels of genetic variation between the X chromosome and autosomes can reveal the different demographic histories of males and females of a species. Taking this approach, two new studies report that the effective population sizes of men and women differ, but they disagree as to which sex outnumbered the other.

Figure 1

Contrasting patterns of X-chromosomal and autosomal diversity. Data are from Keinan et al. and Hammer et al.. (a) Pairwise sequence diversity values for the X chromosome (π_X) and autosomes (π_aut). (b) Ratios of X-chromosomal to autosomal sequence diversities (π_X/π_aut), with and without divergence corrections used by each study. A horizontal line is drawn at 0.75, the expected value for the ratio. YRI, Yoruban (Ibadan, Nigeria); CHB, Han Chinese (Beijing, China); JPT, Japanese (Tokyo, Japan); CEU, CEPH (Utah residents with ancestry from Northern and Western Europe),.