The media reported last week that genes from Neanderthals protect many of us against severe Covid-19. Those genes actually come from Denisovans too: another early human species. Unfortunately, a different set of Neanderthal genes increases our chances of serious Covid. This post goes behind the news and looks at our connection to these two prehistoric creatures, as well as their genes’ impact on Covid risk. It also looks at those genes’ frequency among modern ethnic groups.
I reported in an earlier post that Homo sapiens once shared the world with at least four other hominins: four other species of upright, tool-making, fire-burning people. The four are Neanderthals, Homo erectus, Flores hobbits (Homo floresiensis), and the Denisova hominins. We know of the Denisovans only from a single fossilized finger bone, or possibly two fossils. Scientists identified them as a separate species through extracted DNA. Well, now we’ve got evidence of a fifth species in the Lord of the Rings world of prehistory, and it’s more mysterious even than the Denisovans. That’s because we have no fossils for the fifth species. Continue reading “Homo ghostus”