310: Three major beetle groups come up one testicle short

Three major beetle groups come up one testicle short | Science Blog:

A surprisingly large number of beetles are missing one of their testes, the male gonads of insects. As far as the researchers who discovered this can tell, the insects are not in any way bothered or impaired by this absence.

That group of beetles shares a suite of characters, their missing testicle is their inheritance from a common ancestor.