Natural selection on human Y chromosomes

TL;DR

This paper reviews recent evidence of natural selection acting on human Y chromosomes, highlighting the importance of considering selection effects in population genetics studies.

Contribution

It synthesizes recent findings showing natural selection influences on Y chromosome regions, challenging the assumption of neutrality in population genetic analyses.

Findings

Purifying selection detected in X-degenerate genes

Positive selection may influence testis-related genes

Natural selection impacts Y chromosome evolution

Abstract

The paternally inherited Y chromosome has been widely used in population genetic studies to understand relationships among human populations. Our interpretation of Y chromosomal evidence about population history and genetics has rested on the assumption that all the Y chromosomal markers in the male-specific region (MSY) are selectively neutral. However, the very low diversity of Y chromosome has drawn a long debate about whether natural selection has affected this chromosome or not. In recent several years, the progress in Y chromosome sequencing has helped to address this dispute. Purifying selection has been detected in the X-degenerate genes of human Y chromosomes and positive selection might also have an influence in the evolution of testis-related genes in the ampliconic regions. Those new findings remind us to take the effect of natural selection into account when we use Y chromosome in population genetic studies.