We don't ignore it. There's just not very much high quality evidence, and — unlike climate change — knowing that the distribution curve for blue vs green people is shifted over 5 IQ points gives virtually nobody any actionable information. Generally, in fact, it's leapt upon by people who don't understand the evidence or enough statistics as a cover for their prejudice.
What's so supposedly obvious? The best sprinters and marathon runners both are "black" according to conventional racial categorization. If you want to tell whether someone is likely to be a good sprinter, looking at their "race" alone is practically useless.