This microscopic animal hasn't had males or sex in tens of millions of years

Bdelloid rotifers are a whole class of freshwater microorganisms with no known males, reproducing by cloning themselves for an estimated 35 million years or more — a timespan most biologists thought should doom a species to extinction from accumulated genetic damage. They survive partly by an extreme trick: when their habitat dries out, they shrivel into a dormant state and can repair hundreds of shattered DNA strands once rehydrated, even after radiation doses that would kill most animals.

— Class described across decades of evolutionary biology research, Bdelloidea — Class Bdelloidea