You've prompted me to look up the definition of race. 'Ethnic groups' seems to be the definition for the dictionary and 'sub species' with regards to animals. It's another reminder as to why labels are often not much use other than to develop pre-conceptions.
I'm a pasty redhead, so what dark skin tells me is that you are less likely to get sunburnt than me! Lol!
RE: Why Race Really Truly Isn't an Actual Thing