Integrating sex-bias into studies of archaic introgression on chromosome X

• Evidence of interbreeding between archaic hominins and humans comes from methods thatinfer the locations of segments of archaic haplotypes, or ‘archaic coverage’ using thegenomes of people living today. As more estimates of archaic coverage have emerged, ithas become clear that most of this coverage is found on the autosomes— very little isretained on chromosome X. Here, we summarize published estimates of archaic coverageon autosomes and chromosome X from extant human samples. We find on average 7 timesmore archaic coverage on autosomes than chromosome X, and identify broad continentalpatterns in this ratio: greatest in European samples, and least in South Asian samples. Wealso perform extensive simulation studies to investigate how the amount of archaic cover-age, lengths of coverage, and rates of purging of archaic coverage are affected by sex-biascaused by an unequal sex ratio within the archaic introgressors. Our results generally con-firm that, with increasing male sex-bias, less archaic coverage is retained on chromosomeX. Ours is the first study to explicitly model such sex-bias and its potential role in creating thedearth of archaic coverage on chromosome X.

Subject headings

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)