Isn't it true though that you can tell someone's race by their genome, skeletal structure, and other physical traits apart from skin color? Additionally, is it not also the case that race is generally agreed to result from geographic isolation, and that if that persisted long enough, speciation might occur?
Not stating this is reality. I'm genuinely curious what the science is on this.
No, unless with "race" you mean something other than the ordinary meaning of the word. You can find those differences and draw lines between populations, but they don't overlap very well with the folk interpretation of race.
The traditional concept of race (i.e. the one where "white", "black", "asian" and so on are well-defined terms) is scientifically untenable (fact) and socially harmful (opinion).
There are some narrow use-cases where the concept can be fruitfully applied. For example, some diseases are correlated with genetic characteristics themselves correlated with race. If you are a physician making a diagnosis, the patient's race is usually very apparent; you can and should make use of that information. But that's just keeping the English friar happy, correlation does not imply causation.
Not stating this is reality. I'm genuinely curious what the science is on this.