Evolution of sex chromosomes in Sylvioidea songbirds
Sex chromosomes were discovered more than 100 years ago. They have been studied intensely from a theoretical perspective since then, giving rise to a large body of testable predictions about their evolution from autosomes. A common feature of sex chromosomes is recombination suppression between the sex chromosome copies (X and Y in male heterogametic systems, or Z and W in female heterogametic sys