Why did humans take over the world while our closest relatives, the Neanderthals, became extinct? It's possible we were just smarter, but there may be surprisingly little evidence to support this.
Neanderthals had large brains, language and complex tools. They dealt in art and jewellery. They were clever and suggested an interesting possibility. Perhaps the elemental differences weren’t at the person level, but inside our societies.
Two hundred and fifty thousand years ago, Europe and western Asia were the lands of the Neanderthals. Homo sapiens lived in southern Africa. Estimates vary, but perhaps 100,000 years ago modern humans migrated from Africa.
Forty thousand years ago, Neanderthals disappeared from Asia and Europe, replaced by humans. Their slow, inevitable substitute suggests that humans had some advantage, but not what.
Anthropologists once considered Neanderthals to be dumb bastards. However, recent archaeological finds show that they rivaled us in intelligence.
Neanderthals mastered fire before we did. They were deadly hunters, taking down large game akin to mammoths and woolly rhinos, and small animals akin to rabbits and birds.
They collected plants, seeds and shellfish. Hunting and foraging all of those species required a deep understanding of nature.
Neanderthals also had a way of beauty, creating beads and cave paintings. They were spiritual individuals who buried their dead with flowers.
Stone circles present in caves could also be Neanderthal temples. Like modern hunter-gatherers, Neanderthal life was likely steeped in superstition and magic; their skies stuffed with gods, caves inhabited by ancestral spirits.
Added to that is the undeniable fact that Homo sapiens and Neanderthals had children together. We weren't that different. But now we have encountered Neanderthals over and over, over many millennia, at all times with the identical result. They disappeared. We stayed.
Hunter-gatherer society
Perhaps the important thing differences were smaller at the person level than on the societal level. You can't understand humans in isolation, just as you may't understand a honey bee without considering its colony. We value our individuality, but our survival is linked to larger social groups, just because the fate of a bee is determined by the survival of the colony.
Modern hunter-gatherers provide our greatest guess at how early humans and Neanderthals lived. People akin to the Khoisan of Namibia and the Hadzabe of Tanzania gather their families into traveling groups of ten to 60 people. Teams come together to form a loosely organized tribe of a thousand or more people.
These tribes lack hierarchical structures, but are united by a typical language and religion, marriages, kinship and friendships. Neanderthal societies can have been similar, but with one major difference: smaller social groups.
Tight tribes
This is indicated by the evidence that Neanderthals had less genetic diversity.
In small populations, genes are easily lost. If one person in ten carries the curly hair gene, then in a bunch of ten people, one death could remove the gene from the population. In a bunch of fifty people there shall be a carrier of the gene – many backups. Over time, small groups are likely to lose genetic variation, leading to fewer genes.
In 2022, DNA was recovered from the bones and teeth of 11 Neanderthals present in a cave within the Altai Mountains in Siberia. Several people were related, including the daddy and daughter – they got here from the identical team. They also showed low genetic diversity.
Because we inherit two sets of chromosomes – one from our mother and one from our father – we feature two copies of every gene. We often have two different versions of a gene. You can get one blue eye gene out of your mother and one brown eye gene out of your father.
But Altai Neanderthals often had one version of every gene. According to the study, the low diversity suggests they lived in small groups – probably averaging just 20 people.
It's possible that Neanderthal anatomy favored small groups. Being strong and muscular, Neanderthals were heavier than us. Therefore, each Neanderthal needed more food, which meant that the earth could support fewer Neanderthals than Homo sapiens.
Neanderthals can have eaten mainly meat. Meat eaters would get fewer calories from the land than meat and plant eaters, again resulting in a smaller population.
Group size matters
If humans lived in larger groups than Neanderthals, this might give us a bonus.
Neanderthals, strong and expert with spears, were probably good warriors. The frivolously built humans probably counterattacked, using bows to attack from a distance.
But even when Neanderthals and humans were equally dangerous in battle, if humans were also outnumbered, they may herald more warriors and absorb more casualties.
Large societies produce other, more subtle benefits. Bigger teams have more brains. More brains to unravel problems, remember the knowledge of animals and plants and techniques of constructing tools and sewing clothes. Just as large groups have greater genetic diversity, they may even have greater diversity of ideas.
And more people mean more connections. Network connections grow exponentially with network size, in accordance with Metcalfe's law. A 20-person team has 190 possible connections between members, while a 60-person team has 1,770 possible connections.
Information flows through these connections: news about people and animal movements; tool techniques; and words, songs and myths. Moreover, group behavior becomes increasingly complex.
Consider ants. Individually, ants usually are not intelligent. But interactions between tens of millions of ants allow colonies to construct elaborate nests, obtain food, and kill animals over and over larger than the ants. Similarly, groups of individuals do things that nobody else can – design buildings and cars, write complex computer programs, fight wars, run corporations and countries.
Humans usually are not unique in having large brains (whales and elephants have them) or in having huge social groups (zebras and wildebeests form huge herds). But we’re unique at combining them.
To paraphrase the poet John Dunne, no man – or any Neanderthal – is an island. We are all a part of something greater. Throughout history, people have created increasingly larger social groups: gangs, tribes, cities, nation states, international alliances.
Perhaps then the flexibility to construct large social structures gave Homo sapiens a bonus over nature and other hominin species.
Nicholas R. Longrich, Senior Lecturer in Paleontology and Evolutionary Biology, Life Sciences on the University of Bath.
This article has been republished from Conversation under Creative Commons license. Read original article.
Image Source: Pixabay.com
