Species is used in the sciences, but it’s made it into the vernacular, and there it’s illustrated by an example like this — we don’t refer to a “race of dogs”. Race still refers to division by one or more visible characteristics, such as skin tone, hair color, shape of the skull, etc. Since there’s really only one race, the human race, there’s not any meaningful breeding barrier between “races”. Often a species is identified by whether it is more or less isolated from breeding with similar things (flower with flower, equid with equid, etc) and/or can be bred with a superficially different organism but produce a fertile offspring. Using species to identify fossil forms relies (ironically) entirely on the morphology, that is, division by visible characteristics.
Thanks for the clarification!
No, we don’t refer to races of dogs, we DO refer to BREEDS of dogs, denoting something very similar to what is meant by races of humans. No one would say there are no breeds or varieties of dogs and it is meaningless to say there is only one race of humans. Obviously there is only one SPECIES of humans currently as there is only one SPECIES of dogs. I don’t know what is taught now but when I went to school so long ago we were taught in biology class that two closely related species such as horse and donkey may be able to produce offspring but the offspring will be infertile or perhaps in rare instances they may produce a third generation but the third generation will be infertile. If they could interbreed and produce fertile offspring they were said to be of the same species regardless of differences in appearance. By that DEFINITION there could be no neanderthal DNA in modern humans unless neanderthals were actually of the same species as we.
I wish people would drop this line of, “There is only one race, the human race.” That makes no more sense than saying there is only one breed of dog or horse etc. The fact that all modern humans can interbreed and produce offspring only means they are the same SPECIES which has zero to do with the concept of race. People who say there is only one human race sound as confused but in a different way as my long dead uncle who said that black people were not human, ignoring the fact that there were children of mixed race living near him. Obviously those children would not have existed if blacks and whites were not both human but to claim that those children were not the result of mixing two racial heritages is just as foolish. Words must have meanings if we are to communicate and to pretend that race and species are the same thing is to rob words of a meaning.
The focus on morphology was driven by science. Now it must be driven out.