title: Parallel divergence and degradation of the avian W sex chromosome.
abstract: Sex chromosomes are ubiquitous in birds but our understanding of how they originated and evolved has remained incomplete. Recent work by Tsuda et al. on tinamou and ratite birds suggests that, although all bird sex chromosomes evolved from the same pair of autosomes, the Z and W sex chromosomes have diverged from one another several times independently. This parallel evolution of the avian W presents a means for comparison in studies of sex chromosome evolution, which could help us understand more about the general forces that shape the development of all types of sex chromosome.
authors.affiliation: Uppsala University, Evolutionary Biology Centre, Department of Evolutionary Biology, Norbyvägen 18D, SE 752 36, Uppsala, Sweden.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Mank
authors.forename: Hans
authors.initials: H
authors.lastname: Ellegren
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001717:Birds; D012730:Sex Chromosomes; D019849:Sex Determination Processes