Neanderthals, our closest evolutionary relatives, became extinct due to a combination of anatomical and cognitive disadvantages, suggests new research published in the journal “Proceedings of the Royal Society B.” Scientists from the University of Oxford and the Natural History Museum in London have discovered that Neanderthals had larger eyes than modern humans, leading to significant differences in brain structure and function.
Neanderthals, who lived across Europe, Central Asia, and the Middle East for up to 300,000 years, had brains similar in size to those of Homo sapiens. However, a new analysis shows that the organization of their brains was different. A larger portion of the Neanderthal brain was dedicated to vision and body control, necessary for coping with the long, dark nights at higher latitudes where they evolved. This adaptation meant less brain capacity was available for higher-level cognitive processes such as social networking, innovation, and cultural development.
Lead author Eiluned Pearce from the Institute of Cognitive and Evolutionary Anthropology at the University of Oxford explains, “Since Neanderthals evolved at higher latitudes and had bigger bodies than modern humans, more of their brain would have been dedicated to vision and body control, leaving less brain to deal with other functions like social networking.”
This limitation in cognitive function likely impacted their social structures. Smaller social groups would have made Neanderthals less resilient in the face of environmental challenges. They had fewer allies during times of resource scarcity and were less capable of maintaining cultural knowledge and innovations over generations. This made it harder for them to adapt to the harsh and fluctuating climates of their time, contributing to their eventual extinction.
Comparative studies of the skulls of 32 Homo sapiens and 13 Neanderthals showed that Neanderthals had significantly larger eye sockets, suggesting bigger eyes and a larger visual cortex. This anatomical difference is believed to have restricted their ability to form large social groups, crucial for survival in challenging environments. The archaeological record supports this theory, showing that Neanderthals transported raw materials over shorter distances and had fewer symbolic artifacts, indicating limited trade and communication networks.
While Neanderthals were highly intelligent and well-adapted to their environment, the cognitive and social advantages of modern humans gave Homo sapiens an edge. Modern humans living at higher latitudes evolved larger brain areas dedicated to vision, similar to Neanderthals, but they also retained larger frontal brain regions for social and cultural functions. This enabled them to develop advanced tools, create warmer clothing, and form larger, more cooperative social networks.
The research concludes that these differences in brain organization and social cognition likely explain why Neanderthals went extinct while modern humans thrived. As Pearce noted, “Overall, if Neanderthals had smaller groups, this could have led to their extinction along a variety of pathways.”
In summary, the combination of larger eyes and bodies, requiring more neural matter for vision and physical control, left Neanderthals with less brainpower for social and cultural development. This ultimately may have contributed to their inability to survive the harsh climates of Eurasia and compete with their more cognitively versatile Homo sapiens cousins.
