Biology and taxonomy aren't really my main areas of scientific interest, but from what I could remember/find "race" is typically used in biology as a synonym for "subspecies." And it also seems that there's a fair amount of debate on whether different human races (in the coloquial sense) are truly different subspecies, either from genetic or morphological standpoints.

 

E.g., one quote I came across in a WP article:

 

"It is often stated that human genetic variation is low compared to other mammalian species, and it has been claimed that this should be taken as evidence that there is no natural subdivision of the human population."

 

Then again, astronomy and cosmology are the only scientific topics I really stay current on (other than CS) - so I could be talking out my arse.