I saw this before. Not bad. I enjoyed it.
As far as the title, yes we do descend from all of our ancestors. By definition.
But he’s making the point that after a given number of generations we won’t have any DNA sequence left in our chromosomes from distant ancestors.
It’s just math.
Right-oh.
“… we won’t have any DNA sequence left in our chromosomes from distant ancestors.”
We will have some DNA from distant ancestors, or we would be born chickens or rabbits.