The cultural conditions of star-shaped phylogenies
In the generality, I think intergroup selection of paternal lineages is the answer to why star-shaped phylogenies are so evident in the phylogenetic record ~4,000 years ago. More precisely, most of the major clades of R1a, R1b, and I1 undergo massive expansion after a sharp reduction in effective population size around this period. The R […]
Y chromosomal star-phylogenies as inter-group competition between paternal lineages
The figure to the left should be familiar to readers of this weblog. It is taken from A recent bottleneck of Y chromosome diversity coincides with a global change in culture (Kamin et al.). Over the past few years a peculiar fact long suspected or inferred has come into sharp focus: some of the Y […]