Fig. 4.

Identification of a known adaptive allele in a human population using multiple ancestry-based methods. We compare multiple methods to detect a well-known example of post-admixture positive selection in an admixed human population from Santiago, Cabo Verde on the Duffy-null allele protective against P. vivax malaria (Hamid et al. 2021). (A) iDAT from Hamid et al. (2021), (B) ancestry outlier detection using a three standard deviation cutoff, and (C) the object detection approach developed in this paper. African ancestry in black and European ancestry in white. The image represents the entirety of chromosome 1 for 172 individuals. The dashed vertical line indicates the position of the adaptive allele. The inferred bbox using object detection (C) is in yellow, closely matching the true bbox centered on the adaptive allele (red) in size and location. The other two methods infer multiple and/or longer regions as potentially under selection.