As far as natural selection is concerned, sex is just about everything. All activities a creature engages in are in service of reproduction. Not surprisingly, the nitty gritty cellular details of reproductive biology are thus of extreme interest to many scientists.
Biologically speaking, males are the members of a species that generate sperm while females produce eggs. But now, scientists from Japan have shown that a female fish can produce fully-functioning sperm—and would all the time, if i