Misestimation of Expected Genetic Differences – A Statistical Note on Some Recent Papers

The expected magnitude of phenotypic differences between human populations under genetic drift is often underestimated. This commentary challenges recent claims of minimal differences by addressing statistical weaknesses in Lala & Feldman[1], Gusev[2][3], and Roseman & Bird[4], specifically the misinterpretation of polygenicity’s role in genetic drift, the failure to adjust for diploidy, and the use of non-standard effect size metrics. Using typically-reported FST values and heritabilities, medium to large phenotypic differences are expected under genetic drift across major human biogeographic ancestry groups. It is noted that specific phenotypic differences may also be shaped by other evolutionary forces, such as convergent or divergent selection, as well as environmental factors. By clarifying the mathematical basis for expected differences, this comment advances the discussion on genetic variance and its implications for human phenotypic diversity.