Positive selection in admixed populations from Ethiopia

Area of Science:

• Human evolutionary genetics
• Population genomics

Background:

• Adaptive selection is crucial for human environmental adaptation.
• Positive selection studies have historically under-examined diverse African populations.

Purpose of the Study:

• Investigate modes and targets of positive selection in five Ethiopian populations.
• Analyze whole-genome sequences to understand evolutionary adaptations.

Main Methods:

• Applied SFselect (site frequency spectrum-based test) for old and recent selection events.
• Utilized integrated haplotype score for recent selection events.
• Evaluated significance through simulations and considered admixture and gene functions.

Main Results:

• Identified both individual loci under selection and groups of genes possibly undergoing polygenic adaptation.
• Detected population-specific and shared signals of selection.
• Highlighted folate metabolism, ultraviolet response, and skin pigmentation as shared adaptive pathways.

Conclusions:

• Detected signals of positive selection in Ethiopian populations, indicating novel adaptations in East Africa.
• Identified numerous targets for future functional research into human evolution.