9.1 Signatures of positive selection
A central question in human evolutionary genetics is what genetic adaptations humans acquired as they migrated into diverse environments.
Fig. 1 (source). The history of human migrations.
The process of evolutionary adaptation leaves characteristic signatures on patterns of population genetic variation. By developing statistics to capture these signatures and applying them to human genetic data, we can uncover evidence of past episodes of positive selection.
Statistics for identifying signatures of selection can be broadly classified into two categories: frequency-based and haplotype-based.