I suppose that the question should be turned around to "Why is it extremely rare to see black people competing in professional swimming?" because it is the absence of this phenotype while watching the Olympics that caused me to ask this question.
So,
- why are there very few black people competing at world class level swimming?
While I'm here I may as well ask the question:
- Why are black people faster sprinters than white people when it comes to world class level?
And of course I want biological reasons.