The physical appearance of Neanderthals, our closest extinct human relatives, has been pieced together by scientists using fossil evidence and genetic data. The term “phenotype” refers to an organism’s observable traits, like height, bone structure, and skin color, arising from its genetic code and the environment. Studying the Neanderthal phenotype gives us a clearer picture of what these ancient people looked like and how they were adapted to their world.
Distinctive Cranial and Facial Features
The Neanderthal skull was markedly different from that of modern humans, characterized by its length and low profile rather than a high, rounded shape. One of their most prominent features was a heavy, double-arched brow ridge above the eye sockets. This facial structure also included angled cheekbones and a large, wide nasal opening. Scientists suggest this large nose was an adaptation for warming and humidifying the cold, dry air of their Ice Age environments.
Another defining characteristic was mid-facial prognathism, where the central part of the face projected forward. This gives the impression that the face was “pulled” from the nose. In contrast to the prominent chins of Homo sapiens, Neanderthals had a receding chin. At the back of the skull, many Neanderthals had an occipital bun, a bony projection that contributed to the elongated shape of their head.
Postcranial Skeleton and Body Proportions
The Neanderthal skeleton reveals a body built for power and cold resilience. They were shorter and stockier than most modern humans, an adaptation that helped conserve body heat in frigid climates. This body plan included a broad, barrel-shaped chest and shorter limbs, particularly the forearms and lower legs, which minimized surface area exposed to the cold.
Their bones were robust, with thick cortical bone and large joint surfaces. This indicates they possessed great physical strength for strenuous lives. These features were not signs of disease or malformation but clear evolutionary adaptations. The combination of a compact build and powerful musculature was suited to their physically demanding lifestyle as hunters of large game in Ice Age Eurasia.
Genetic Insights into Neanderthal Appearance
While fossils provide a blueprint of the skeleton, ancient DNA offers clues into traits that do not preserve over millennia, like soft tissue appearance. By sequencing genomes from Neanderthal remains, scientists have begun to reconstruct these aspects. One of the most significant findings relates to their skin and hair color.
Analysis of the MC1R gene, which influences pigmentation, suggests that at least some Neanderthals likely had pale skin and red hair. The specific genetic variant they possessed is different from the one that causes red hair in modern humans, representing a separate evolutionary path to this trait. Further genetic studies indicate that Neanderthals were probably varied in their appearance, with different populations exhibiting a range of skin and hair tones.
Phenotypic Legacy in Modern Humans
The Neanderthal legacy continues within the DNA of many modern humans. Due to interbreeding tens of thousands of years ago, populations outside of Africa inherited a small percentage of Neanderthal DNA. This genetic material influences a variety of observable traits in people living now.
This inherited DNA has been linked to our physical and biological selves. For instance, certain Neanderthal gene variants affect skin biology, influencing traits like skin tone and how skin reacts to sun exposure. Other sequences have been associated with the immune system, shaping how the body responds to pathogens. While Neanderthals have vanished, a part of their phenotype lives on, woven into the biology of modern humanity.