Recent discoveries in Science and Nature, have suggested the Genome is much younger than was previously thought. Cf.
https://www.nature.com/articles/nature.2012.11912
https://www.nature.com/articles/nature11690
Their work suggests mankind's genome has been degenerating via mutations only over the past 5000-10,000 years, and that this is "important to fully understand our evolutionary history".
This does appear to fit in with other data on the existence of the earliest civilisations, being of relatively young origin, and the questionable nature of Darwin's conjecture :
Cf.
https://www.researchgate.net/publication/331324292_Retraction_Note_A_brief_history_of_human_evolution_challenging_Darwin%27s_claim?isFromSharing=1