4 junio 2015
In many animal species, the chromosomes differ between the sexes. The male has a Y chromosome. In some animals, however, for example birds, it is the other way round. In birds, the females have their own sex chromosome, the W chromosome. For the first, researchers have mapped the genetic structure and evolution of the W chromosome.
http://feeds.sciencedaily.com/~r/sciencedaily/~3/70V4Kic8n2o/150604084511.htm
