The mosaic of lactase persistence in Africa: from gene-culture coevolution to continental demography

Lactase persistence (LP), the genetically determined capacity to digest lactose beyond infancy, stands as a prime example of rapid, recent human adaptation and gene-culture coevolution. Across Africa, the distribution of genetic variants associated with LP reveals intricate patterns reflecting a complex interplay between the cultural innovation of dairying, intense positive selection, adaptation to varied environments, and diverse, continent-spanning migratory events. This review synthesizes current knowledge from genetics (including ancient DNA), anthropology, and archaeology (including lipid residue analysis of pottery and paleo proteomics of ancient dental calculus) to explore how LP variants function as powerful bioarcheological tracers of African demographic history, dietary shifts, and cultural transitions within the African continent. By integrating evidence from these multiple disciplines, I aim to illustrate how the evolution and dispersal of LP alleles mirror significant demographic events and cultural innovations throughout Africa's prehistory, highlighting one of the strongest examples of recent human adaptation.