population structure

Novembre J & Peter BM 2016 Recent advances in the study of fine-scale population structure in humans. Curr Opin Genet Dev 41:98-105.

• untrained eyes may overinterpret population clusters in a PCA plot as a signature of deep, absolute levels of differentiation with relevance for phenotypic differentiation
• this is an ironic inverse of what Edwards harshly termed Lewontin's fallacy [4], and what we might instead call Lewontin's nightmare
• we first encourage practitioners to make absolute metrics of differentiation clear to audiences (e.g. F_ST, PCA proportion of variance explained)
• weak levels of differentiation, as measured by F_ST, imply that neutral quantitative traits will be weakly differentiated as well
• visually displaying the geographic distribution of a manageable number of random markers from a dataset can be helpful for students and broader audiences to gain a direct sense of levels of population structure