If humans originated in Africa, how can we have anything other than 100% African DNA?

Question

is there some sort of cutoff point where scientists decided “everyone in Ireland 100,000 years ago will be considered 100% Irish”?

In: 12

Answer 1

It’s a matter of definitions, at the end of the day. Humans share the vast majority of our DNA with each other anyways – hell, we share most of our DNA with bananas. But the traits that help us to tell someone’s ancestry down to specific countries are the traits that either developed after humans began to migrate to various places around the world, or else they’re traits that became super common in specific populations.