Figure 4.

Fraction of human polymorphic positions carrying derived alleles in Neandertal and human DNA sequences. (A) Neandertal sequences of increasing length that overlap human polymorphic positions were assessed for having the derived or ancestral (chimpanzee-like) allele. Blue points are for Neandertal data, red points for the corresponding sequences in the human reference genome (hg18). (B) Sequences of length 60–78 nucleotides were split in half and re-analysed (‘30–39'). Derived alleles are preferentially lost when fragments size is reduced.