Complex sentence: The exact mechanisms of the evolution and maintenance of gens is still a matter of some research, however, it is believed that in Common Cuckoos, gens-specific properties are sex-linked and lie on the W chromosome of the female.
Split into simpler sentences: The exact mechanisms of the evolution and maintenance of gens is still a matter of some research. However, it is believed that in Common Cuckoos, gens-specific properties are sex-linked and lie on the W chromosome of the female.