Songbirds appear to have an extra chromosome in cells involved in sexual reproduction. The extra DNA could help explain why there are so many songbird species
Source:
https://www.newscientist.com/article/2201146-weird-chromosome-may-have-spurred-evolution-of-thousands-of-songbirds/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home