Most living organisms reproduce sexually, an efficient way to exchange and shuffle genes, leading to evolution. How about organisms that do not have sex?
How do animals evolve without having sex - short science news

How do animals that do not have sex evolve, since no genetic transfer occurs in the reproductive process? A new study looked into this dilemma using the Bdelloid rotifers as animal models. They are all females and they reproduce by cloning, however, they successfully evolved into more than 500 species. The study proved incorrect a previous theory that claimed that rotifers evolve through genetic mechanisms occurring after periods of dehydration. Alternative solutions to this problem could be the transfer of genetic material from other species, or even the presence of males (although they have never been discovered). For the moment the mystery of these animals remains unsolved.

Read the full story: Imperial College London
Scientific publication: PLOS Biology