Africans Asians Europeans – social constructs

While I share 99,9% of my genes with all humans beings. Of the one permille only a tenth correlats with "race" and out of these genes only a handful relate to visible features that are used as markers of "race".
There may be a gene that affects blood pressure, that is quite common in West Africa and very rare in Europe. Statistically it may be true that a certain drug is more efficient among Afro-Americans than among Euro-Americans. But since there are some Swedish Americans with that "African gene", and many Afro-Americans without it, it makes no medical sense to treat humans according to "race".
Europe is clearly a social construct. Anaximander, Anaximenes, Heraclitus, Anaxagoras, Diogenes Apolloniates, Archelaus, and Thales lived and worked in Asia, but are considered Europeans. The Himalayas are much higher than the Urals, but India is called a subcontinent, Europe a continent. Finnish and Hungarian are Uraltic languages, Persian a European. But let's assume we know where Europe is (excluding Malta, Cyprus and the Canaries, but including Rhodes and Iceland) and who is European (including Basques, Sami and Afrikaner), let's assume we can agree on the borders of Africa (without the Sinai and Madagascar), where do we put the Arabs, where the Arian Iranians?
There are some people who consider themselves as "belonging to the African race," just as their are people who considern themselves "born gay."
Social constructivism is often misunderstood as claiming "free choice". But that people are not Black or Gay by birth, does not mean they can choose the color of their skin or their sexual preferences. In a society that classifies humans by height or body type (leptosomic, athletic, pyknic) or by leg form (knock knees or bow-leg) skin color plays no social function – just like some prefer blond or black hair, some might prefer hazelnut or pink skin. Observing long distance runners, wrestlers and swimmers from different countries and very different skin color, only a die-hard racist can deny that most top long distance runners look the same; so do most professional wrestlers (and weight lifters).