Neanderthals, also known as Homo neanderthalensis or H. sapiens neanderthalensis, were an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. They were humans like us, but a distinct species that lived alongside early modern humans for at least part of their existence. Here are some key facts about Neanderthals:

• Neanderthals had a long evolutionary history, with the earliest known examples of Neanderthal-like fossils dating back around 430,000 years ago.
• They were adapted to living in cold, dry environments and had distinctive facial features and a stocky build.
• Neanderthals were generally shorter and had more robust skeletons and muscular bodies than modern humans.
• They had a long, low skull with a characteristic prominent brow ridge above their eyes.
• Neanderthal brains were roughly the same size as ours, although they were more elongated.
• Neanderthals were likely ambush hunters who lived in a forested environment.
• They were adaptable and lived in cold steppe environments in England and Siberia about 60,000 years ago, and in warm temperate woodlands in Spain and Italy about 120,000 years ago.
• Neanderthals were able to make sophisticated tools and weapons.
• They had a complex social life and were able to communicate with each other, although their language may have been simpler than ours.
• Neanderthals and modern humans (Homo sapiens) evolved from a common ancestor between 700,000 and 300,000 years ago and inhabited the same geographic areas in western Asia for 30,000–50,000 years.
• Genetic evidence indicates that while they interbred with non-African modern humans, they ultimately became distinct branches of the human family tree (separate species) .
• Up to 4% of the DNA of humans living outside of Africa can be traced back to Neanderthals, indicating that they did interbreed with humans.

Despite their species demise, fascinating remnants of Neanderthals can be found in the genetic material of some modern humans. The overlap shows that Neanderthals did interbreed with humans.