The concept of race isn't just about recognizing biological variation in the human species; it's about asserting that this variation is divided into distinct groups.I don't think you get the point of my race debate thread. No one's arguing that there's different subspecies of human in existence today. To use a crude analogy, we would all agree that domesticated dogs are members of the same species (Canis lupus familiaris) but we would agree that there's different "breeds" of dogs. That's much like what is found in humans in terms of variation. Accepting that there's biological variation within the human species does not, in of itself, lead to racism. Scientific racism is pseudoscience.
I don't think the comparison with dog breeds is valid. Breeds are distinct because they've been artificially bred to distinct standards. Even within those standards, heredity doesn't guarantee breed: a purebred dog with purebred parents of the same breed but that doesn't meet the breed guidelines isn't considered an "official" example of the breed. Also, most dogs ("mutts") have no breed.