What's the "genetic history" behind being black? If it means basically anything other than that your ancestors came from Africa in the past 100k years, you're m

What's the "genetic history" behind being black? If it means basically anything other than that your ancestors came from Africa in the past 100k years, you're missing many groups commonly considered "black" like Australian aborigines and Negritos. If that is your definition, then basically everyone is black. Where's the utility in that?