Editing Sex-determination system (section)

=== Sex-chromosome turnover ===
The '''sex-chromosome turnover''' is an evolutionary phenomenon where sex chromosomes disappear, or becomes autosomal, and autosomal chromosomes become sexual, repeatedly over evolutionary time. Some lineages have extensive turnover, but others don't. Generally, in an XY system, if the Y chromosome is degenerate, mostly different from the X chromosome, and has X [[Sex-chromosome dosage compensation|dosage compensation]], then turnover is unlikely. In particular, this applies to humans.<ref>{{Cite journal |last=Vicoso |first=Beatriz |date=December 2019 |title=Molecular and evolutionary dynamics of animal sex-chromosome turnover |url=https://www.nature.com/articles/s41559-019-1050-8 |journal=Nature Ecology & Evolution |volume=3 |issue=12 |pages=1632–1641 |doi=10.1038/s41559-019-1050-8 |bibcode=2019NatEE...3.1632V |issn=2397-334X}}</ref><ref name="Zhu-2024" /><ref>{{Cite journal |last1=Palmer |first1=Daniela H. |last2=Rogers |first2=Thea F. |last3=Dean |first3=Rebecca |last4=Wright |first4=Alison E. |date=November 2019 |title=How to identify sex chromosomes and their turnover |journal=Molecular Ecology |volume=28 |issue=21 |pages=4709–4724 |doi=10.1111/mec.15245 |issn=0962-1083 |pmc=6900093 |pmid=31538682|bibcode=2019MolEc..28.4709P }}</ref>

The ZW and XY systems can evolve into to each other due to [[sexual conflict]].<ref>{{Cite journal |last1=van Doorn |first1=G Sander |last2=Kirkpatrick |first2=Mark |date=2010-10-01 |title=Transitions Between Male and Female Heterogamety Caused by Sex-Antagonistic Selection |journal=Genetics |volume=186 |issue=2 |pages=629–645 |doi=10.1534/genetics.110.118596 |issn=1943-2631 |pmc=2954476 |pmid=20628036}}</ref>