Neanderthals

Neanderthals were a close evolutionary relative of modern humans that developed distinctive adaptations to Ice Age Eurasia. Fossils and genetic evidence place their lineage in Europe and western Asia by at least 400,000 years ago, with some earlier fossils showing related anatomy.¹ Their bodies were generally shorter and more heavily muscled than those of many modern humans, with broad trunks, large noses, and substantial brow ridges—features often interpreted as adaptations to cold climates, though body form also varied geographically.

They occupied environments extending from Britain and Iberia to the Levant, the Caucasus, and parts of Central Asia. Neanderthal populations were not uniform: groups living in warmer southern regions differed in anatomy, technology, and diet from those in northern habitats. Their brains were at least as large on average as those of modern humans, but brain size alone does not reveal how either species thought or behaved.

Neanderthals were capable toolmakers and flexible hunters who used local materials and adjusted their practices to changing environments. The Mousterian stone-tool tradition, associated with many Neanderthal sites, includes prepared-core techniques that produced sharp flakes and points. They used fire, processed animal hides, and hunted large mammals such as deer, ibex, and wild horse, while also gathering plant foods and exploiting smaller animals where available.

Archaeological evidence shows that some Neanderthals transported pigments, selected unusual feathers or shells, and made personal ornaments, although the meaning and frequency of these practices remain debated. Injuries found on skeletons suggest that disabled or seriously hurt individuals sometimes survived long enough to receive sustained assistance from companions. Sites such as Shanidar Cave in Iraq provide especially important evidence for Neanderthal social life and mortuary behavior.²

Neanderthals and modern humans encountered one another repeatedly rather than meeting only during a single final migration. Homo sapiens reached western Eurasia by at least 45,000 years ago, overlapping with Neanderthals for several thousand years in some regions. Their disappearance was probably caused by interacting factors, including small and fragmented populations, climatic instability, competition, disease, and gene flow into expanding modern-human groups; no single explanation accounts for every site or region.

Ancient DNA transformed the picture of this encounter. The Neanderthal genome shows that interbreeding occurred, probably mainly after modern humans left Africa, and most present-day people with substantial non-African ancestry carry roughly 1–2 percent Neanderthal-derived DNA.³ These inherited segments influence some immune responses, skin biology, and other traits, but they are not a simple measure of Neanderthal identity or behavior.

Neanderthal research includes several findings that complicate the stereotype of a uniform, brutish species. Dental calculus can preserve microscopic food remains and proteins, revealing that diets differed sharply between groups: some relied heavily on meat, whereas others consumed plants and occasionally cooked them. Genetic studies also identify substantial variation among Neanderthal populations, including signs of repeated population replacement and isolation in parts of the Caucasus and Siberia.

The name comes from the Neander Valley near Düsseldorf, Germany, where a fossil found in 1856 helped establish the species in scientific debate. Taxonomists have disagreed over whether Neanderthals should be treated as a separate species or as a subspecies of modern humans, but genomic evidence confirms that they were a distinct long-standing human lineage that exchanged genes with ours. Their legacy therefore survives both in fossils and in living genomes.

Homo neanderthalensis

The scientific name commonly given to the Neanderthal species.

Mousterian

A Middle Paleolithic stone-tool tradition strongly associated with Neanderthal occupations, though its makers were not necessarily always Neanderthals.

Ancient DNA

Genetic material recovered from archaeological remains and used to reconstruct past populations and relationships.

Gene flow

The movement of genetic variants between populations through reproduction.