Deep Genealogy — I’m An Above-Average Neanderthal
Let’s talk deep genealogy.
When you hear the word “caveman,” what comes to mind?
For me, “caveman” conjures up images of a hairy man wearing animal skins, with a low forehead, huge muscles, and a stooped posture. He is pre-verbal and communicates in grunts and body motions. Ooga Booga. He carries a large wooden club and is violent and misogynistic, dragging “his” females about by their hair. And he lives in a literal cave!
You can send a sample of your spit into various companies to have it analyzed for DNA, and at least one company will tell you what portion of your genome is Neanderthal, the original “cave people.” My own DNA, at almost 2% Neanderthal, is above average, but not by much. If you are of European, Asian, or North American ancestry, you will find that you also have some Neanderthal DNA, because the source population of modern humans for all of these places was the same, and that population interbred with Neanderthals long ago.
A while back, President Biden referred to the lifting of mask mandates in Mississippi and Texas as “Neanderthal behavior.” The implication was that lifting the mandates was anti-survival and against the interests of the country as a whole. This comment set off a flurry of indignant responses from the right at being compared to cavemen, as well as a few people proclaiming their pride in being compared to a group of resourceful hunter-gatherers.
My DNA test had me feeling a little like a caveman, and it sparked curiosity about what my Neanderthal ancestors were really like. I wanted to know more about this “deep ancestry” and you might, too. How did that DNA get into my genome? And what made early modern humans so successful in displacing Neanderthals?
There is a lot of new research into Neanderthals and as usual, it turns out that many of the old ideas are not true.
Not Your Grandpa’s Neanderthals
Neanderthal is the designation for a species of human which existed from about 500,000 years ago to about 40,000 years ago. They are named for the location of the first skeletal remains, the Neander valley in modern day Germany. Originally they were assumed to be a rung below modern humans on an “evolutionary ladder” — sub-human cavemen. Early inaccurate reconstructions of Neanderthal skeletons showed them with a stooped posture, and this led to the famous “Ascent of Man” diagram, with a series of pre-humans pictured with progressively better posture. However, later reconstructions showed they walked fully upright and DNA analysis has shown they are not the ancestors of modern humans, but rather our cousins on a parallel branch of the family tree. That diagram was wrong.
A common ancestor of both modern humans and Neanderthals is the small-brained, upright walking Homo erectus. When a group of Homo erectus left tropical Africa, there were new selective pressures which caused certain traits to be emphasized. After many generations of genetic isolation from the rest of the early human population, this population was distinct enough to be a unique species, Homo neanderthalensis.
Scientists speculate that the selection pressures were mostly around a colder and more unpredictable climate. Compared to modern humans, the Neanderthals’ wider noses warmed and moistened incoming cold air; shorter, more compact bodies conserved heat; bigger eye sockets helped with vision in low light; and greater strength and endurance was useful for hunting large animals, which was a prime way to get calories during long winters. These high calorie diets also fueled a radical expansion in the brain size. These adaptations allowed Neanderthals to populate much of the Eurasian continent.
Neanderthals were amazingly successful by many measures:
- They spread out over a wide geographic area and persisted for hundreds of thousands of years.
- They controlled fire and had diverse diets.
- They developed sophisticated stone tools, made jewelry, and probably had rudimentary art and music.
- They likely had some degree of social complexity, with some distinct gender roles.
- Within that complexity, like modern human hunter/gatherer societies, they were likely egalitarian; sharing what was hunted and gathered equally was of prime importance to the survival of the community.
- They walked upright and their jaw and ear structures indicate that they were as capable of speech as modern humans.
- They made their own clothing, made tipi-like shelters, and only occasionally lived in caves.
- They cared for their injured and elderly, and they buried their dead (which helped preserve their remains for us to find).
- They were stronger and had more endurance than modern humans and could likely see better than modern humans, especially at night.
- They were highly intelligent and had brains that were physically larger than even modern humans.
The Observed Effects of Neanderthal DNA
Scientists are busy trying to find out what effects Neanderthal ancestry might have on present day humans. They compare people like me to folks with no Neanderthal DNA at almost 4000 sites on the genome. Some of those sites are part of genes that have been linked to physical or behavioral traits (although the tie between behavior and genetics is tenuous, at best). Any differences seen so far seem to be barely statistically significant, and none of the studied traits would make me more violent or misogynistic.
Among the weakly correlated traits are a slightly greater chance to have social fear, depression, promiscuity, autism, and bi-polar disorders. Those with more Neanderthal DNA were also slightly more likely to be less imaginative. Some of these traits make some sense, because Neanderthals lived in much smaller social groups than the modern humans who replaced them.
A few “Neanderthal” traits I personally have (according to 23andMe): one chromosome variant which makes it slightly harder to discard unneeded possessions (check), one variant that makes me like sweet foods more than salty foods (guilty), and one variant that makes me more likely to sweat during a workout (embarrassingly, yes).
There are also a few Neanderthal variants I have which don’t seem to have affected me: one variant that makes me less likely to be afraid of heights (nope — still scared of heights) and one variant that would make me a better sprinter than distance runner (not great at either, frankly).
Why did Anatomically Modern Humans displace Neanderthals?
After at least 350,000 years populating the Eurasian continent, the Neanderthals finally met their cousins, Homo sapiens, anatomically modern humans. These modern humans slowly took over the space occupied by Neanderthals, and occasionally interbred with them, resulting in the Neanderthal DNA which is present in my genome. Eventually Neanderthals as a separate species lost out to modern humans, and only live on in snippets of our DNA.
Modern humans (Homo sapiens) evolved separately from Neanderthals about 300,000 years ago in Africa from Homo erectus. About 45,000 years ago, as small groups of these anatomically modern humans left Africa, they encountered Neanderthals in the part of the Middle East known as the Levant. This was a key moment because as these early humans encountered each other, the physically weaker modern humans began to displace the physically stronger Neanderthals. This process took about 5000 years until the last enclaves of Neanderthals disappeared. There was something different about modern humans which contributed to their success. What was it?
The old idea was that modern humans were just superior to Neanderthals and they out-competed them or killed them off. Recent studies have revealed that it was more complicated than that. There are several theories.
It could have been diseases. The modern humans came from Africa, which had a huge gene pool by comparison, including many species of primates which would share diseases with early modern humans. In addition, modern humans lived in groups that were likely at least three times bigger than typical Neanderthal groups, which increased their daily exposure to pathogens. These modern humans would have evolved resistance and immunity to multiple diseases to which the Neanderthals had no previous exposure. Think about how the European and African diseases affected New World humans, reducing Indigenous populations by as much as 95% after first contact. This might have given modern humans the advantage they needed.
It could have been hunting and warfare techniques. Neanderthals were powerful hunters, but they did not develop projectile technology. Analysis of their tools and the many healed bone fractures suggests that Neanderthals killed their large prey animals up close and fought in close quarters. The bone fractures on Neanderthal remains reminded scientists of modern day rodeo cowboys’ fractures. This was dangerous and difficult. Modern humans developed the bow and arrow about 80,000 years ago, which was a safer and more effective way to hunt, and to make war.
It could have been habitat loss. Fossil evidence suggests Neanderthals had evolved to be effective predators on large animals. Without projectile technology, they would not have been able to extirpate a prey species from a given area, thus ensuring the sustainable continuation of their food source. Modern humans with projectiles would have been killing machines by comparison, possibly eliminating the primary food sources for Neanderthals.
It could have been climate. Although Neanderthals were physically evolved for colder temperatures, modern humans had evolved social structures that allowed them to cooperate in large groups, which may have been more adaptable in the face of changing climates.
It could have been any of the above reasons or a combination, but much of the speculation about the advantages held by modern humans focuses on differences in social grouping size between the two species. Research shows that Neanderthals stayed in small direct kin-based groups of 20 to 40 people, while modern humans lived and moved in larger groups, likely 100 to 150 people (as shown by evolutionary anthropologist Robin Dunbar). Next month I will take a deep dive into early human social dynamics.
Getting Beyond the Old Ideas of Neanderthals
What does this have to do with the ongoing topic of these essays, which is: what does it mean to be a white, heterosexual, Midwestern male in today’s world? At the outset of this essay I asked about the word “caveman,” and I noted that the stereotypical picture of a Neanderthal is linked with violent masculinity.
When someone calls you a Neanderthal, they are putting you into an out-group with their name calling — which is trademark behavior of Homo sapiens, with our large and complex social groups. Whenever there is an out group, there is the risk of generalizing and harmful stereotypes. But it is also a very typical Homo sapiens behavior to include people and work together for a common purpose. By including people and challenging stereotypes, we can begin to see the world as it is and not just through our filters.
It is important that we examine stereotypes about ancient people because any stereotype, even of an extinct species of early humans, reveals as much about the people who have the stereotype as it does about the object of the stereotype. In this case, early scientists, mostly white men, projected violence and misogyny back onto the Neanderthals.
Violent masculinity is based on defending heterosexual male privilege. Our old ideas of Neanderthals were a defense of this version of masculinity, essentially saying that “this is how it has always been.” But research is showing that neither Neanderthals nor early modern humans were simply macho “cavemen.” Rather they, like modern hunter/gatherer societies, were likely people who relied on men and women working together as equals. They were part of complex societies, and they were successful because they developed empathy, caring, and social awareness.
The early scientists assumed superiority for themselves and for modern humans and they assigned grunts and stooped posture to these “inferior” Neanderthal humans, who were originally erroneously assumed to be a step below us on an evolutionary ladder. Coincidently, white scientists also projected violence and inferiority onto the Indigenous people of their day. We are the inheritors of this thinking, and until we examine it, we cannot step outside of the superior/inferior binary.
Why Do I Care About Neanderthals?
It is ironic that when someone wants to insult someone else, they sometimes call them a caveman or a Neanderthal. The implication is that the person being insulted is less intelligent or less evolved. Every indication is that Neanderthals were highly intelligent and well adapted for their environment. They survived as a species on this planet for several hundred thousand years, which is longer than modern humans have been around. Perhaps we could learn something from Neanderthals? Their way of life did not destroy their habitat, as ours is doing.
When I think about my own Neanderthal DNA and learn about the lives of Neanderthals, it encourages me to rethink any sense of superiority I have towards any other groups of humans. Each person or species is adapted to the life they lead. Each is intelligent and physically adapted for what they do. And each person or species is worthy of respect.
As successful and intelligent as they were, Neanderthals lost out to anatomically modern humans, and went extinct. Why? An exploration of that “deep genealogy” question will be the subject of next month’s story.
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Notes on sources:
When I became curious about Neanderthals, the internet was my friend. Psychology Today has a good series of articles, which I reference below. Also science magazines and newspapers love to write stories about new discoveries through DNA analysis and fossil records. I invite you to follow me down that rabbit hole.
Psychology today articles:
Robin Dunbar on human evolution:
Basic info about Neanderthals:
https://www.vox.com/science-and-health/2018/11/15/18095687/neanderthal-nature-savages-hea
