Note: In this series, we explore the genetic evidence that indicates humans became a separate species as a substantial population, rather than descending uniquely from an ancestral pair.
In the last two posts in this series (here and here), we have been exploring the anti-evolutionary arguments of Dr. Vern Poythress in his brief book Did Adam Exist? – specifically, his arguments alleging that that the human and chimpanzee genomes are only 70% identical. As we have seen, this line of argumentation is intended to call human – chimpanzee common ancestry into question, in part because shared ancestry is used in some methods of estimating the ancestral population size of our lineage. Since Poythress intends to argue that human ancestral population genetics cannot establish that humans descend from a population, rather than a pair, attempting to undermine confidence in common ancestry is part of the overall thrust of the book.