Gut microbes may put barrier between species

Removing bacteria in wasps saves crossbred offspring from death

Nasonia  vitripennis (shown) and N. giraulti wasps may remain distinct  species because of their gut microbes, not just genetics, a new study suggests. 

M.E.Clark/Wikimedia Commons

SNOWBIRD, Utah — The bazillion microbes teeming inside bigger creatures may be an overlooked but vital part of what divides the big organisms into species.