"Race" comprehends three concepts: bio-genomic clusters commonality, biological race and social race.

The analysis of bio-genomic clusters has a very narrow scope and lets us infer, for instance, that a group of humans might be Ashkenazi Jews for having certain genetic conditions that predispose them to the Tay-Sachs disease. Of course, members of other groups could have the same or similar genetic condition and, actually, there are far more differences within populations than there are between them.

Race in biology means a group within a species so different from the rest that it's on a definite path towards the constitution of a new species. In this sense there are no subspecies races among humans.

Lastly, social habits and norms clearly make remarkable distinctions between ethnic groups, and this has social and economic effects.

More here: http://www.philosophersmag.com/index.php/footnotes-to-plato/87-are-races-real