Do you think this is a racist statement/theory? I think it is very touchy, but is ok to at least discuss.?

I was reading one theory on why Black Americans tend to dominate (in numbers) for certain sports. The author acknowledges that certain sports, such as basketball, will see a proportionately higher number of successful black athletes due the popularity of said sport within their particular demographic group (i.e. b-ball is popular in urban, poorer neighborhoods). However, the author also puts forth the idea that Blk Americans who have a direct linage to slaves brought from Africa (describing the vast majority of America’s Black population), have inherently "stronger" genetics--a "survival of the fittest" situation created for those transported over slave routes. That is, the arduous journey on board the brutal conditions of slave ships, served to create a condition which naturally favored the survival of only the most "fit individuals". This, he believes, leads naturally to the greater likelihood in finding “natural athletes” who are Black over those whom are White.