Bdelloid rotifers are microscopic freshwater invertebrates. No one has ever seen a male. Thus, researchers hypothesized that these species reproduce solely by asexual means. What evidence supports this hypothesis?
Based on the information being described within the question it can be said that the main evidence supporting this is that Bdelloid rotifers exhibit much more variation in their pairs of homologous genes than most sexually reproducing species. This is mainly because sexually reproducing species there tends to be lots of crossing over which creates a mechanism that gets rid of most harmful mutations from appearing thus allowing for higher survival rates.
