I may have to give Nova another chance. It won't be easy, though.
I pretty much haven't watched it in about 20 years, since the program on the "wild man" of Hunan Province, China. In the intro, they said it was based on the work of Ohio State physical anthropologist Gary Poirier (pronounced as French). I thought "What a coincidence, I took physical anthro at Ohio State from Frank Poirier (pronounced the way it's spelled, of Armenian decent). And he's interested in the same kind of stuff."
Then they showed "Gary Pwa-ree-ay" and it was the guy I had at OSU, Frank Poirier. The whole show was based on his work, he was on-camera a lot, and they got his name completely wrong. Made it hard for me to take "Nova" seriously after that.
There was also the NOVA episode about how MIT invented radar in WWII. (Hint: MIT didn't invent radar.)
Anyway, Clayton Cramer recommends the episode on Kennewick Man, and is even planning to use it in the American History class he teaches. So I may have to break my two decade NOVA fast.
From a teenager, I wondered why the possibility of humans in the New World prior to about 20,000 years ago, was so taboo. Then I heard an anthropologist stating, with heavy emphasis, that DNA evidence proved beyond any doubt that the ancestors of today's Native Americans arrived in the New World more recently than 20,000 years ago, and therefore any evidence of humans in the New World prior to then, must be rejected.
And the penny dropped. The problem was that any humans in the Americas prior to 20,000 years were not ancestors to today's Native Americans, but were replaced by them. That overturns the whole "First Americans" noble savage narrative. Hence the taboo.
Kennewick Man stirred this pot but good, since his remains were first identified as Caucasian, then as possibly related to the Ainu, the aborigines of Japan. (The Ainu themselves were originally identified as Caucasian by the first Europeans to study them.) And he was carbon-dated to 9,300 years ago.
So Kennewick Man gives us this picture: an aboriginal New World population is displaced by the ancestors of today's Native Americans. This is inconceivably anti-PC. If Kennewick Man turned out to be Caucasian, it would be Slartibartfast's-signature-on-the-glacier-level proof that God exists and has a sophomoric sense of humor. Native American tribes in the Kennewick area wisely invented a cultural aversion to DNA testing of ancient, unidentified remains. Who knows how many faculty clubs would have been littered with exploded brains otherwise.
BTW, one of Poul Anderson's "Time Patrol" novels features a time-traveling anthropologist studying an encounter between New World aborigines and Palaeo-Indians. I suspect it's a lot more accurate than the politically correct narrative where the aborigines never existed.