Homo neanderthalensis successfully lived in the cold, harsh ice-age conditions of Europe until becoming extinct approximately 30 000 years ago. Adaptations which enabled them to survive for up to 400 000 years included:

• short and stocky bodies
• large noses
• cave dwelling
• living in groups of 8 - 25 individuals, with females moving between different groups
• each group was territorial with territories covering about 50 km2
• hunting large herbivores
• surviving on a diet of up to 90% meat, as shown by bone and faecal analysis
• cutting up meat using stone tools, which were slightly different for each group.

The genome of H. neanderthalensis has been sequenced using nuclear DNA extracted from bones. This has allowed comparisons with the genome of modern H. sapiens. From the data it is believed that the two species shared a common ancestor, most likely H. heidelbergensis, 270 000 - 440 000 years ago. There are DNA sequences in H. sapiens that are known to vary between individuals by only a single base. Researchers analysed these DNA sequences from H. sapiens populations in Western Europe, Southern Africa, West Africa, China and Papua New Guinea and compared them with H. neanderthalensis. It was found that H. neanderthalensis and non-African H. sapiens populations had 4% of their DNA in common. These DNA sequences are unique to them, and not found in the H. sapiens from the African populations.