You have to be careful with "explain" - sure you can "explain" anything with a presumed genetic disposition. That is in general not really a proof, only yet another theory. I just wanted to point out that there are alternative explanations.
For example, Europeans tend to be really good at soccer, whereas Americans suck at it. Is it genetic? I highly doubt it, since the European genes are readily available in the US. It has a cultural reason (simple statistics - popular sports - higher percentage of kids trying it - higher percentage of talents being discovered).
I want to add to this a question, because I truly don't know: who are the kids picking up running 100m distances as their main sport? What is their motivation? I can imagine why people get into team sports, for example, but I can't imagine a huge number of people go into 100m running out of intrinsic self motivation, simply because it is so much fun to run 100m?
So maybe the "system" matters much more for 100m running than for most other sports. The system being things like "scholarships in exchange for sports", the way talent gets identified and promoted, and so on. Just saying that this would be another aspect that might distort the statistics.
I recently heard the quote "Jamaica is too small to have their own drug testing agency"...
For example, Europeans tend to be really good at soccer, whereas Americans suck at it. Is it genetic? I highly doubt it, since the European genes are readily available in the US. It has a cultural reason (simple statistics - popular sports - higher percentage of kids trying it - higher percentage of talents being discovered).