I wish I cold explain it to you correctly, but I probably cannot. Let's assume, for example, that the Asians and the Native American had a common ancestor. Let's assume, likewise, that Europeans and Eurasians also stem from a common stock somewhere in the past. Next, let's assume that both of these branches lead back to their own common ancestor, and that that ancestor had in turn a common ancestor with African races. Now, from that first human, trace the branches forward, using genetics somehow as they did, and find the person who is equally distant (or close) to every modern human genotype. Amazingly, when they did find him in that tent in Kazakhstan, he appeared as if he could "pass" in almost any part of the world, except the darkest parts.
As I say, I am not really doing their presentation justice, but, FWIW, that's what I got out of it.
Thanks. Though your description sounds more like “the most average human.”
I guess I’ve never really understood what is meant by “direct descendant,” much less “more direct descendant.” How is one person a more direct descendant than his cousin?