http://en.wikipedia.org/wiki/Race_(biology)

In biology, a race is any inbreeding group, including taxonomic subgroups such as subspecies, taxonomically subordinate to a species and superordinate to a subrace and marked by a pre-determined profile of latent factors of hereditary traits.
Biologically, "race" is the correct term.

http://en.wikipedia.org/wiki/Race_(c...f_human_beings)

Anthropologically, there is debate as to whether "race" is the correct term, especially given amount of genetic mixture between races in modern cultures, but that debate is primarily driven by political correctness and not real science. Race is simply a subset of genetic traits that tend to breed true.

The "only one race" line makes a nice bumper sticker, but it isn't scientifically accurate. Humanity is a species (http://en.wikipedia.org/wiki/Species), as marked by humanity's ability to reproduce with fertile offspring.

Redefining terms for purposes of political correctness is a slippery-slope fraught with unforeseen peril. To use a racial example, since it's the topic of this thread, I was once taken to task for using the term "black" instead of African-American -- which might have made sense if the audience hadn't been multi-national. Go call a Frenchman who happens to be black an African-American and let me know how that works out for you ...