Most of us harbor about 2 percent Neanderthal DNA, inherited when our ancestors bred with Neanderthals more than 50,000 years ago. This was revealed back in 2010, when geneticists salvaged enough fragments of ancient DNA from Neanderthal bones to piece together a full genome. The discovery squelched a longstanding debate over whether Neanderthals and modern humans met — they did — and mated — oh yeah.
But why do we only have 2 percent Neanderthal ancestry? And what are the effects of that