Among human species, analysis of alternative types has been confined to Neanderthals and Denisovans, so far. And we have discovered that the Wonder that is We are not purebred. We’re mostly sapiens but our pedigree is mutt.
We have learned that up to roughly 2 percent of your genes come from Neanderthals. We may also have genes from Denisovans (a sort of eastern Neanderthal), especially if we are Negrito Filipinos, in whom 6 percent of DNA is Denisovan. Tibetans also have relatively high Denisovan contributions, and, more startlingly, it turns out that so do Icelanders. Did some Denisovan get spectacularly lost tens of thousands of years ago? (There are other possibilities; their actual range remains a mystery.)
We even learn that some modern humans have faint genetic hints from past crossbreeding with an unidentified archaic human – meaning, a hominin. The archaic signal is strongest in some West Africans, but we too may harbor genetic whispers from this “ghost,” which split off from the sapiens line about half a million years ago, the relevant scientists estimate.
Anybody else lurking in our bodies? Maybe. There is nothing in recorded human history, or police records, to indicate that humankind is fastidious in mating choices. But in the last 20 years, our image of ourselves has forever changed.
