Neanderthals were an archaic human species which separated from our own modern human lineage early in the Middle Pleistocene era, approximately 2.6 million to 11,700 years ago. From fossils that have been discovered, we know that they then spread across Europe and Asia and lived there from approximately 400,000 years ago up to 40,000 years ago. Because they did not live within Africa, we can see their contributions to modern-day humans in every population outside of Africa.
Scientists were able to fully sequence the Neanderthal genome in 2010, and further sequencing has taken place in more recent years, revealing more about our distant relatives, and allowing scientists to build up a picture of how they may have looked. We also know a little about their behaviours from artefacts found with their remains.
They walked upright like us, and are likely to have had a stocky build with a prominent brow ridge. Their remains show that they were well adapted to living in colder climates.
Although the popular depiction of a Neanderthal is that of a club-weilding brute capable of little more than grunting to communicate, recent studies (beginning in the 1980s and published from the early 2000s) have shown that they were in fact capable of language, complex tool use,and even creating art.