FAIL - OP never suggested skin color was a main factor. There are hundreds of visible phenotypes that tend to group and therefore categorize people by origin. It's clear enough that skeletal remains can often be identified by racial origin. I expect most ppl can make an accurate guess in a large fraction of cases, between (for example) Chinese, Korean and Japanese East Asians after seeing the fully clothed individual.
[Deleting two paragraphs quoted by Babbylonian, upthread.]
Species is generally defined by distinct groups than can't successfully interbreed, while 'race' is an old but correct term for populations with a species that generally exhibit distinct phenotypes. So Oats and Wheat are distinct species, but all across Europe in the middle ages there were distinct 'land-races' of wheat. More commonly called 'varietals.
Yes it's always absurd when people are so cowed by political thinking that the deny reality, and agree that 2+2=5 for political reasons.
No. I once suggested to a small group that Hillary Clinton didn't look particularly Greek, and all the politically blinded Lefty zealots gasped and whined as tho' I had used the N' word toward her. I don't think her features, hair, skin tone are particularly Mediterranean (tho' I'd be the first to admit low accuracy on this categorization). I harbor no negative stereotypes wrt Greek ppl generally.
It's silly, but no - it is not acceptable in this Liberal PC gulag to suggest national/regional origins.
Why is this a "problem" ? Yes, we are one species and individuals interbreed across phenotypic boundaries and therefore introduce added genetic variability into sub-populations. "Black" isn't just skin color - for example it isn't used to refer to Hindus with much darker skin color than Obama. The term seems to mean something like "some significant African ancestry" (where African means the more West/Central/South excluding perhaps Berbers and more recent S.African migrants from Euope & India.
The problem is that SOME overly-sensitive people take offense at any sort of categorization, and also in recent decades we entertain the PC nonsense POV that no one should ever be offended. It's sort of a passive-aggressive anger, derail the conversation thing.
Yes ppl should take umbrage at false or over-inclusive generalizations, abt any groups, including ethnic, national or racial groups. I'd argue that false elevation of groups is at least as harmful as false denigration. OTOH there are evidenced generalization that really do need to be discussed and nearly impossible when some of the dishonest participants in the national debate believe that the term "racism" roughly means "doesn't agree with me" and use the accusation of racism to derail discussions of fact.