Edward O. Wilson is a well-known entomologist whose specialty was ant species. In his later years he concluded that he was also an expert in evolutionary anthropology. He wrote a book titled The Social Conquest of Earth in which he made the following claims.
“Our bloody nature, it can now be argued in the context of modern biology, is ingrained because group-versus-group was a principle driving force that made us what we are. In prehistory, group selection lifted the hominids that became territorial carnivores to heights of solidarity, to genius, to enterprise. And to fear. Each tribe knew with justification that if it was not armed and ready, its very existence was imperiled. Throughout history, the escalation of a large part of technology has had combat as its central purpose.”
“It should not be thought that war, often accompanied by genocide, is a cultural artifact of a few societies. Nor has it been an aberration of history, a result of the growing pains of our species’ maturation. Wars and genocide have been universal and eternal, respecting no particular time or culture.”
Perceiving our history as one being decided by the actions of blood-thirsty males is a popular conception within the ranks of male anthropologists. Female anthropologists tend come up with conceptions that are much less dominated by male violence. Recorded history contains plenty of data both for and against Wilson’s viewpoint. But what about prehistory? He claims “wars and genocide have been universal and eternal,” but could that be true?
One of the most intriguing mysteries about human history involves the exact interactions characteristic of our species, Homo sapiens, as it encountered other human-like (hominin) species both as they evolved in Africa and after they spread across the world. What we know is that we were latecomers to the vast Eurasian land mass. Other hominins had lived in those areas for hundreds of thousands of years before we arrived. It would take tens of thousands of years, but eventually all traces of the other hominins would disappear as we became the dominant species. What explains this development? Were we culturally superior in some way, or did a propensity for violence play a role? While our recent history includes plenty of examples of war and genocide, are those behaviors the result of cultural effects or, as Wilson suggests, are they inherent in our biological makeup? If so, one might expect frequent and early violent interactions between our species and the differing hominins they would encounter.
The best hope for understanding this interaction involves the fate of the Neanderthals who had a long history in Eurasia prior to the arrival of our species. A surprising amount has been learned about these people in recent years. Rebecca Wragg Sykes provides a comprehensive picture of them and their society in her book Kindred: Neanderthal Life, Love, Death and Art (2020). We will also delve into conjectures on the Neanderthals’ fate by Yuval Noah Harari in Sapiens: A Brief history of Humankind (2015), and Jonathan Kennedy in Pathogenesis: A History of the World in Eight Plagues (2023).
We will use Sykes’ dating convention: 1ka means one thousand years ago; 1Ma means one million years ago. There were numerous hominin groups that evolved in Africa with some traveling to the Eurasian continent as long as 1-2Ma. A branch would develop that around 500ka would split off to three specimens that are most associated with the population of that region: Denisovans, Neanderthals, and Sapiens (us). Neanderthals would spread across most of the continent and reside for about 3-400 thousand years. The Denisovans appear to be most common in Asian areas. Sapiens left little record of inhabitance until 70-60ka. The three groups were similar enough that interbreeding was possible. Neanderthal-Sapiens breeding was most common in European regions, Denisovan-Sapiens breeding more common in Asian regions. After about 40ka, evidence of Neanderthal existence disappeared.
Harari postulates that Sapiens dominated all others because it underwent a ”Cognitive Revolution” that allowed it to develop into larger groups and with this increase in number came more rapid introduction of new capabilities.
“The appearance of new ways of thinking and communicating, between 70,000 and 30,000 years ago, constitutes the Cognitive Revolution. What caused it? We’re not sure. The most commonly believed theory argues that accidental genetic mutations changed the inner wirings of the brains of Sapiens, enabling them to think in new and unprecedented ways and to communicate using an altogether new type of language.”
This was an hypothesis, and the credibility of this claim of a cognitive revolution has not held up well. And the more we learn about Neanderthals and contemporary Sapiens, the more similar they become in terms of capabilities. Harari suggests Neanderthals might have disappeared because Sapiens could out-compete them for resources, or that the dominant Sapiens could have implemented their first example of genocide. Yet, if two sides are to be locked in conflict, tens of thousands of years is a long time for that to finally be resolved. And resolve itself without leaving a trace.
Rebecca Wragg Sykes provides a detailed description of all that has been learned about Neanderthals and makes comparisons between their ways and those of the Sapiens. Just since Harari produced his volume, our understanding of these creatures has surged, greatly assisted by the availability of genetic analyses.
“While there has been a lot of back-and-forth debates over this, today it appears that Neanderthal vocal chords could make pretty much the same range of sounds as ours. There were perhaps some subtle differences in vowels…but their breath control wasn’t appreciably poorer, giving them the ability to utter lengthy sound combinations. Moreover, though their inner ear shape was slightly different, it was similarly finely tuned to sound frequencies generated by speech. If this anatomy in humans is regarded as specialized for language, then the Neanderthals cannot have been so different. The same thing is true of brains: in your head right now, Broca’s area is busy understanding the words on this page, and it was also well developed in Neanderthals, with neurons that would have lit up as well-practiced hands knapped a Levallois core, or even when children watched elders butchering.”
The understanding of Neanderthals has been hindered by a form of Sapiens supremacy theory. They compared well with Sapiens when it came to stone-age technology.
“The enduring myth that Neanderthal technology was stuck in some kind of cognitive mire, bogged down by minds unable to innovate, is false. These were neither unsophisticated nor fixed and unvarying people…Elemental boundaries—what the geology made possible or prevented—surely imposed constraints, but thanks to technical mastery and a laser focus on what they wanted, creative responses were possible. As routinely as breathing, Neanderthals paid attention to their rock: selecting the choicest types, playing with novel ways to fragment, shifting concepts and skills as needed.”
When Sykes considers the disappearance of the Neanderthals, she points out that they were a considerably less robust society than Sapiens. Perhaps they had a lower sex drive, or maybe they tended to be introverts rather than extroverts. Though they had lived for hundreds of thousands of years and survived many environmental challenges, they mostly confined themselves to small, relatively isolated groups with not a lot of genetic mixing. In fact, their population had been in decline for some time when Sapiens arrived.
“Though some Neanderthal lineages were less genetically isolated than others, overall the wider population had been slowly withering for hundreds of thousands of years. For all their cleverness, flexibility and resilience, the archeology does suggest they had weaker and smaller social networks made up of small groups that rarely came together in large gatherings. Long-distance lithic movements get more extreme and more common as the Upper Paleolithic develops, and crucially, things other than stone begin to be carried far. Shared symbolic networks reflecting connections with far-flung communities are what define the post-Neanderthal world. Being welcomed at the fires of friends many valleys away might make the difference between infants getting by on milky dregs, or tiny hollow bodies being laid down in cold crevices.”
“Small tragedies over thousands of years could ramp up as localized genetic pools became cut off and sluggish. In contrast to long histories of genetically small worlds and within-group reproduction visible (but not universal) in Neanderthals, so far no early H. sapiens genomes point to similar processes.”
“Climate meltdown, plus a much more crowded continent, could have provided the stage for our persistence and the passing of the Neanderthals.”
Since Sykes was writing her book during the Covid pandemic, it did occur to her that a severe disease that hit the continent could have contributed to the end of the less socially robust specimens. That brings us to the view espoused by Jonathan Kennedy: if there was conflict between Sapiens and Neanderthals it was waged by the pathogens each brought to the battlefield.
All species harbor microbes that can cause disease. Those that survive the infection will gain immunity and continue on. The disease will become endemic in a given population as new members are added (generally through birth) and become infected. Wherever a given population goes it will carry its pathogens with it. The Neanderthals living in Eurasia for hundreds of thousands of years in a colder climate and low population density would have developed a set of pathogens to which they were immune. Sapiens, emerging from tropical Africa where the density of species that could transfer pathogens to them was much higher, would carry with them a much higher pathogen burden. There are many instances in recorded history in which the peoples with the most complex microbial burden dominate over those with the less powerful microbial array who then can become extinct. Think of the European invasion of the Americas.
Kennedy suggests that Sapiens and Neanderthals interacted at a border region where pathogens were exchanged, and interbreeding allowed the exchange of genes developed to aid immunity. Sapiens, with the greater pathogen burden would gain immunity to Neanderthal pathogens faster than that species could respond to Sapiens diseases. Once significant numbers had gained immunity, Sapiens could penetrate into Neanderthal territory and encounter peoples with no immunity to them and decimate the population. It would take many thousands of years for Sapiens to distribute itself through the vast areas inhabited by the Neanderthals, but the end result was inevitable.
Each of the three viewpoints could have played a role in the Neanderthal demise. It is likely to never be understood in detail. However, it is encouraging that none demand violence as an explanation. While it’s appropriate to be disappointed that wars and violence have played such a huge role in our societies, it is unnecessary to conclude we have always lived that way.
Sykes’ suggestion that the Neanderthals created a society/culture which was not designed to survive certain changing conditions is intriguing. Perhaps it is something we should be concerned about as our societies face new threats arriving at an accelerating rate.
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