Below is a fascinating lecture which argues that
Therian (placental) mammals are genetically modified
(by retroviral infections) organisms. In essence,
human biology is shaped by stolen genes.
Paleovirology: Ghosts and Gifts of Ancient Viruses
Harmit Malik, Principal Investigator,
Fred Hutchinson Cancer Research Center
Harvard Museum of Natural History Lectures
https://www.youtube.com/watch?v=a-WG21Ck9PQ
https://www.youtube.com/channel/UChjF1Bz-Fx4WFGRqfVbjcrA
Yours,
Paul H.