All Humans Have Some Trace of Neanderthal DNA

DNA contains all the information that makes up all living things, but it also reveals interesting facts about our past. For one thing, all humans share 99.9% of the same genes, with the 0.1% caused by substitutions, deletions, and insertions in the genome (an important tool for understanding diseases). We also know, thanks to DNA, that humans are much less genetically diverse than other animal species. This means that all 8 billion humans today grew from a population of only 10,000 breeding pairs of Homo sapiens, and that our ancestors likely experienced genetic bottlenecks that caused serious population declines.

Amazingly, glimpses into our human lineage are also locked away in our DNA, because every human on the planet has some genetic material adopted from a completely different species of human — Neanderthals. Although Homo sapiens are the only human species on the planet today, the Earth has played host to upwards of 20 different human speciesthroughout millions of years. For a time, Homo sapiens shared the planet with Neanderthals (Homo neanderthalensis) and even interbred with them. Remnants of those dalliances still live within our chromosomes, passed on from generation to generation. Although Europeans and Asians share the largest percentage of Neanderthal DNA (around 2%), Africans also share a small percentage (which wasn’t discovered until 2020).