Positive selection of lactase persistence among people of Southern Arabia

Frequency patterns of the lactase persistence (LP)-associated -13,915 G allele and archaeological records pointing to substantial role played by southern regions in the peopling and domestication processes that involved the Arabian Peninsula suggest that Southern Arabia plausibly represented the center of diffusion of such adaptive variant. Nevertheless, a well-defined scenario for evolution of Arabian LP is still to be elucidated and the burgeoning archaeological picture of complex human migrations occurred through the peninsula is not matched by an equivalent high-resolution description of genetic variation underlying this adaptive trait. To fill this gap, we investigated diversity at a wide genomic interval surrounding the LCT gene in different Southern Arabian populations.