Data from: Sex uncovered special issue: selective maintenance of recombination between the sex chromosomes

A hallmark of many sex chromosomes is the dramatically reduced rate of
recombination between them in the heterogametic sex (e.g., between the X
and Y). Sexually antagonistic selection is thought to be the main
selective driver of this reduced recombination, with tighter linkage
strengthening the association between alleles favourable to females and
the X, as well as alleles favourable to males and the Y. Nevertheless,
many sex chromosomes retain substantial levels of recombination over
millions of years, and some old sex chromosomes remain homomorphic with
few signs of recombination suppression and the chromosomal degradation
expected to follow. This paper explores the selective factors that can
maintain recombination between the sex chromosomes. Specifically, by
analysing the dynamics of genes that modify the rate of recombination, I
present results demonstrating that certain forms of selection – all
involving overdominance in males – can positively maintain recombination
in the pseudo-autosomal region. To understand these cases, one has to
revise our standard view of sexual antagonistic selection as involving two
partners (males and females) to three partners (the X in females, the X in
males, and the Y).