I finally got a copy of Paabo's recent book. See earlier profile in the New Yorker.
Neanderthal Man: In Search of Lost GenomesThe essential difference between moderns and pre-moderns is likely a qualitative increase in cognitive ability. See Neanderthals dumb?
(p.213) ... we estimated that the total number of DNA sequence positions at which Neanderthals differed from all humans living today will be on the order of 100,000. This will represent an essentially complete answer to the question of what makes modern humans "modern," ...
(p.253) [last paragraph of the book!] ... One can imagine putting such changes into cell lines, and into mice [or monkeys] ... in order to "humanize" or "neanderthalize" biochemical pathways or intracellular structures ... One day, we may understand what set the replacement crowd [moderns] apart from their archaic contemporaries, and why, of all the primates, modern humans spread to all corners of the world and reshaped, both intentionally and unintentionally, the environment on a global scale ...
See also The genetics of humanness, The Neanderthal Problem, and Genetic engineering of monkeys using CRISPR.
