Aug 26 2008
Neanderthal Intelligence
Homo neanderthalensis (Neanderthal Man) is our closest cousin, so our fascination with them is understandable. How closely related are we? How did we interact when we shared the planet up until 28,000 years ago? Who was more intelligent? Why are we still here and they are not?
Our image of Neanderthal Man also reflects, even encapsulates, our current ideas about evolution and our recent ancestors. Originally Neanderthal Man was visualized as brutish, hunched over, and dumb – the very icon of primitive (even still reflected in those Geico cave-man commercials). This image reflected our biases more than our science. Over time the facts slowly hammered our image into at least something more physicaly accurate: Neanderthal man was fully upright, they were not necessarily any more hairy than Homo sapiens (us), and they had a brain that was on average larger than modern humans.
But despite their larger brain size, which can reasonably be explained in part by their more robust physical stature, we still clung to our belief in Homo sapien superiority. After all, we are still here and they are not. We won.
The bias that most colored our view of Neanderthal man is the belief that evolution is an inherently progressive process. Evolution, it was believed, led through imperfect and primitive stages until finally achieving its pinnacle in Homo sapiens. But Stephen J. Gould and others spent their careers smashing this image of evolution. Gould argued that evolution is not inherently progressive. It merely adapts species to their local and immediate conditions. Any “progress” is purely an epiphenomenon. Gould’s non-progressivist view of evolution has dramatically shifted the consensus view of how evolution plays out over time, but there are still those who feel (and I think with good reason) that there may be a statistical trend toward something that can meaningfully be called progress at some times in some evolutionary lineages. This remains, as far as I can tell, a point of contention.
At the very least the current view of evolution is that it is not necessarily progressive. And further we must expunge the notion that ancestor species were incomplete and in the process of evolving into their descendants. Rather, they simply were what they were – they were adapted to their environment and weren’t necessarily in the process of becoming anything. Also, almost every species that has ever lived has become extinct – extinction is natural and inevitable. It does not represent inferiority or flaws. It usually just reflects bad luck – and everyone’s luck eventually runs out.
Back to Neanderthals – they were a successful species adapted to the European ice age. Homo sapiens evolved in Africa and then later migrated to Europe and elsewhere. From about 40,000 years ago to 28,000 years ago we shared Europe with the Neanderthals. This certainly sparks the imagination – what would it be like to share the planet with another (even closely related) intelligent technological species? Did we compete with them, trade and interbreed with them, or ignore them?
So far the evidence suggests that we did little if any interbreeding with Neanderthals. So either the Neanderthals simply died out, perhaps as the ice age retreated, or they were out-competed by Homo sapiens, or something else happened. Explanatory biases mentioned above favored the out-compete hypothesis. One line of evidence for sapiens superiority lies in our superior tool kit – we had better stone tools than the Neanderthals. Specifically sapiens were able to craft more slender flint blades while Neanderthals crafted broader blades. It was assumed for decades that the more slender blades were more efficient – they used less resources, created more cutting surface, and lasted longer.
A new study by researchers at the University of Exeter, Southern Methodist University, Texas State University, and the Think Computer Corporation, have found all of these assumptions to be false. They spent three years making flint tools and comparing the results. They found that the Neanderthal stone knife was just as efficient in terms of use of resources, cutting surface, and longevity as the Homo sapiens’ more slender flint knife. The press release gives this explanation of the results:
Now that it is established that there is no technical advantage to blades, why did Homo sapiens adopt this technology during their colonization of Europe? The researchers suggest that the reason for this shift may be more cultural or symbolic. Eren explains: “Colonizing a continent isn’t easy. Colonizing a continent during the Ice Age is even harder. So, for early Homo sapiens colonizing Ice Age Europe, a new shared and flashy-looking technology might serve as one form of social glue by which larger social networks were bonded. Thus, during hard times and resource droughts these larger social networks might act like a type of ‘life insurance,’ ensuring exchange and trade among members on the same ‘team.’”
I love the experimental approach to archeology and challenging these prior assumptions. However, I think they may be premature in concluding that the slender blade had no advantage over the broader blade. What if the blade was a more efficient killing tool? Perhaps it resulted in a higher percentage of kill success in the hunt, allowing Homo sapiens to survive better during lean times or harsh winters, and simply out-compete Neanderthals for food. It does not appear that this hypothesis was tested.
The popular press is presenting this new research as evidence debunking the “stupid” Neanderthals myth. While this is partly true, that is really just an inference from this data – not something in the data itself. There are also other lines of evidence that Homo sapiens possess intellectual capacity lacking in the Neanderthals – most notably the creation of art. Cro-magnon man left behind cave painting and carved figurines. Neanderthals did not leave behind anything that can be called art.
In fact, Homo sapiens also left behind delicately crafted stone tools – probably useless, but highly decorative. They may have done this to show off their skill. So even if the more slender blades (which were functional) were not more efficient in terms of their production, they may have represented superior skill.
The unresolved (and perhaps unresolvable) question is whether the ability and penchant for creating art represented a superior brain or simply culture. Maybe Homo sapiens benefited from the chance birth of a cro-magnon Einstein – a cave-man genius who planted cultural seeds for the Homo sapiens that the Neanderthals lacked.
Other lines of research are also addressing the question of why Homo sapiens survived when Neanderthals did not. For example, evidence suggests that Neanderthal women joined their men in the hunt, while Homo sapiens had a division of labor between the sexes that gave them greater versatility and perhaps was a decisive advantage over the Neanderthals.
Overall this is an excellent study that addresses one specific question regarding the Neanderthal-Homo sapiens debate. It also raises again the larger concept of the dominant character of evolutionary history – is it progressive, just locally adaptive, or what mix of both. But I do not think this new data ends the debate about whether or not Homo sapiens had distinct advantages over Homo neanderthalensis that enabled the former to out-compete the latter.
36 Responses to “Neanderthal Intelligence”
Leave a Reply
You must be logged in to post a comment.
I’d like more posts like this. When you discuss real scientific controversies as opposed to the false ones that have been manufactured for the media, the differences between the genuine scientific controversies and the manufactured ones are always so striking.
I suspect the larger brain in Neanderthal may have occurred due to a larger maternal pelvis which allowed for a larger brain at birth. This may actually have been detrimental to Neanderthal society. A smaller human pelvis results in substantial infant and maternal death due to cephalopelvic disproportion. With brain size limited at birth, there is greater evolutionary pressure to optimize the function of that brain, and to make trade-offs in different brain functions at constant brain size. I speculate that this may have set the stage for greater specialization in humans, resulting in a larger distribution of cognitive abilities. A village with a significant fraction of specialists in diverse technologies will outcompete a village composed only of generalists, even if the generalists have on average superior abilities. The generalists can’t have superior abilities to each and every one of the specialists.
Paradigm shifting technological advancement isn’t produced by the work-a-day generalists, it is produced by the specialist specializing in that specific technology.
Though some think it pedantic, I favor maintaining Latin forms in technical vocabulary. Homo sapiens is singular, while the plural should be homines sapientes.
You wouldn’t say “one homo neanderthaliensi” and “two homo neanderthaliensis”. It would be homo -ensis (sg.) and homines -enses (pl.).
Conversationally and colloquially we have fine alternatives — humans and neanderthals — and needn’t barbarize perfectly good and useful Latin phrases that have their place. (The real pedantry, I think, would be to quibble over the use of human to mean “pertaining to the species homo sapiens sapiens.”)
The effects of differing cultures on what is passed down is exemplified by the ancient Greeks. The Athenians left us a great treasure of art and literature while little survives from the Spartans.
The homo sapien’s tools are a lot smaller, which probably means you can carry more of them around, more conveniently. If you’re nomadic, a smaller tool could be a big advantage.
I’v been reading Microcosm by Carl Zimmer and found (pages 189, 190) a mention that Neanderthals and humans apparently did interbreed. He discusses a gene known as microcephalin, which plays a central role in the development of the brain, and notes that the version found in Neanderthals is now found in the majority of humans living today.
So it would appear that in some ways the Neanderthals are not only still here, some of their genes are “smarter” than those of our own that they replaced.
I hate to nit-pick, but it’s likely that Neanderthals did have art, although not fully developed. There has been a Neanderthal art object found that is estimated to be 35,000 years old.
http://news.bbc.co.uk/2/hi/science/nature/3256228.stm
This object seems to suggest they had the cognitive abilities to be creativity and exhibited signs of culture. Developmental psychologists have posited that artistic development begins when a person recognizes a familiar form in nature or chaos (good ol’ pareidolia), and then attempts to alter the form to bring it closer to the likeness. For example, children start off scribbling, and suddenly realize one of their scribbles look kind of like a dog, so they add a line for the tail. This face-like object fits right in to that model, suggesting that the Neanderthals were at the beginning stages of their artistic development.
DavidCT wrote, “The effects of differing cultures on what is passed down is exemplified by the ancient Greeks. The Athenians left us a great treasure of art and literature while little survives from the Spartans.”
Well yes, but the Spartans didn’t engage in art and literature. They engaged in politics and war. They were, perhaps, the greatest influence on Plato’s Republic, which describes a civilization nearly identical in organization and ideals to Sparta. The Republic in turn has had a great influence on many aspects of Wester society. To say little survives from Sparta compared to Athens is like comparing apples and oranges.
I f we out-competed them, we’re an invasive species. Nice to know we are what we abhor.
Obviously this is highly speculative work, but it’s fascinating and likely fruitful, at least in getting us to consider what makes us what we are, culture, tools, problem solving, art…
I would think it is, like so many things, a combination of factors we have considered and factors we have not.
You ever read “Eaters of the Dead”?
It was made into a movie called “The Thirteenth Warrior”.
It is an ancient poem translated recently. There is a suggestion that the Eaters of the Dead might have been Neanderthals.
Also, just look at the average kid graduating HS in the US these days. No progressive evolution here in the states at least.
Fascinating post.
The implications of elevating the status of Homo neanderthalensis must be disquieting to creationists, and religious folk generally. A large brained higher primate…. Did he display conciousness? Make decisions? Have a personality? Did he have a ‘soul’?
As for the interbreeding question, perhaps this is early evidence of the discovery of fermentation, and subsequent discovery of ‘beer goggles’….
In case it appears from my earlier comment that I just didn’t understand what I was reading, here’s a bit more on Neanderthals and results of apparent interbreeding with humans:
Excerpt from High-Achieving Genes article found at:
http://www.forbes.com/2007/02/25/genghis-khan-descendants-lead_achieve07_cz_cz_0301khan.html:
“While some chunks of DNA are common today thanks to the conquest of kings or historical flukes, others have become widespread thanks to good old natural selection. People from time to time have been born with mutant genes that gave them a slight reproductive edge, one that their offspring enjoyed as well. These lucky mutants might be less likely to die of malaria, for example, or be better able to tolerate lactose or handle the complexities of full-blown language. In any case, their versions of genes spread through the human population while others dwindled away.
We’ll never know exactly who first carried those adaptive genes. But ultimately that doesn’t matter. It’s the genes, not the people, who have achieved this kind of greatness. The starkest proof of this comes from a gene called microcephalin, which is involved in brain development. All humans carry some version of microcephalin. One version is far more common than the others, found in 70% of all people.
Recently scientists at the University of Chicago compared the different versions of microcephalin to figure out how long ago they all originated from a single ancestral gene. The answer was startling: over a million years ago–long before our species emerged. But weirder still, the most common version of microcephalin only began to spread 37,000 years ago. What was that version of microcephalin doing in the intervening time?
The best explanation for this finding is that the most common version of microcephalin in our species came to us from Neanderthals. Neanderthals and humans evolved from a common ancestor that lived in Africa about half a million years ago. The ancestors of Neanderthals moved out of Africa and arrived in Europe about 300,000 years ago. These rugged, barrel-chested people survived the vast flux of Ice Age rhythms, hunting and building shelters. They had Europe to themselves until about 45,000 years ago, when modern humans arrived from Africa.
The slender, clever Africans came to stay. Over the next 15,000 years or so, Neanderthals shrank back into remote mountain refuges, while modern humans spread across the continent. And then the last true Neanderthal died–yet another species hurled onto the ash heap of extinction.
Neanderthals and humans presumably could have interbred, just as closely related species of other mammals do today. And the microcephalin study suggests that they did. Their Neanderthal-human hybrid children carried genes from both species, but it appears that most of the genes from the Neanderthals gradually disappeared from the human gene pool.
Microcephalin was different, though. Humans who carried the Neanderthal version had more children than those who didn’t, and the gene spread steadily.
Scientists don’t yet know why this particular Neanderthal gene gave humans such a reproductive edge. But scientists do know that microcephalin helps build brains. Its name–which means “tiny head”–comes from the devastating birth defects that can be produced when the gene is crippled by a mutation. So it’s possible that the human mind itself was reshaped by a Neanderthal gene.
In evolution, it seems, achievement is a very strange thing. A gene may break free from its ancestral species and go on to enjoy greatness, even as that species vanishes into extinction.”
Carl Zimmer is the author of At the Water’s Edge and Evolution: The Triumph of An Idea, among other books.
Is it Neanderthal or Neandertal? I think either/or is good.
nwtk2007said “You ever read “Eaters of the Dead”?”
The ancient poem is Beowolf (leader of the Viking group is “Buliwyf”), with the writings of Arab travelers like Ibn Fadman (who was a real person, who mostly wrote about the Vikings who plied the Volga, the Rus, http://www.nordicway.com/search/Vikings%20in%20the%20East.htm ) thrown in for fun. And like all Michael Crichton books, it is a very silly book.
Not really anything to do with Neanderthals. But I wouldn’t put it past Crichton to write another silly book with that kind of premise.
The common variants in microcephalin don’t seem to affect cognitive parameters very much.
http://www.sciencemag.org/cgi/content/full/317/5841/1036a
The connection to brain size occurs in null mutants; the brain is ~1/3 the size. A reduction in brain size to 1/3 for the absence of the gene could occur for many reasons and does not necessarily imply that variations in the gene are responsible for the normal regulation of brain size.
Microcephalin analogs in flies encode proteins that are critically important in DNA replication in early embryos. Disruption of DNA replication could make any organ smaller simply by pathologically reducing cell number.
I am extremely skeptical of any significant Neanderthal influence on human genetics related to cognition. Presumably any Neanderthal genes would be rarer in humans in Africa and there doesn’t seem to be much real differences cognitively between Africans and non-Africans. There isn’t a large difference in brain size or in language or tool making. That is, the variation within African and non-African populations is considerably greater than the variation between African and non-African populations.
daedalus2u,
Why would Neanderthal genes be rarer in humans in Africa than elsewhere when both Neanderthals and humans originated in Africa?
In any case that’s a bit beside the point as to the question of whether there is sufficient evidence of Neanderthal/human interbreeding in Europe.
And have there been any studies of the effects of possible interbreeding between the portions of those populations that didn’t join in the migrations?
Apparently it should be neanderthal, not neandertal as the name was set before the german spelling reformation and therefore shouldn’t change.
However, “Neander Thal” (“Neander Valley”) is pronounced “neandertal”.
Roy Niles: because Neanderthals never lived in Africa, and gene flows have until extremely recently been OUT of Africa, not into it.
Nitpicking:
From article excerpted above:
“The ancestors of Neanderthals moved out of Africa and arrived in Europe about 300,000 years ago.”
Oh and while no longer relevant to the specific question, your assumption that gene flows until recently were only on a one way African street is seriously flawed as well. Think Egypt, for example.
In timescales of hundreds of thousands of years, Egypt IS “extremely recent”.
And note that “the ancestors of” the Neanderthals left Africa.
As did the ancestors of humans. And of Egyptians.
True, Roy, but not relevant to my point, which is that no Neanderthals lived in Africa. By your logic, since the ancestors of the American Indians came from Africa, American Indians lived in Africa.
Well, you are simply wrong, bad analogies notwithstanding. Neanderthols originated in Africa in the same sense that humans did. To quibble that the European versions never actually lived there has no relevance to my original response to the post made by Daedulus.
No, neanderthals originated in Europe, presumably from Homo erectus ancestry. Really. Look it up.
-However, “Neander Thal” (”Neander Valley”) is pronounced “neandertal-
Pronounced…not spelt. When Dave asked the question i assumed he was querying spelling.
Quite correct, eiskrystal. I was digressing.
Quote from Zimmer’s article I cited above:
“Neanderthals and humans evolved from a common ancestor that lived in Africa about half a million years ago. The ancestors of Neanderthals moved out of Africa and arrived in Europe about 300,000 years ago. These rugged, barrel-chested people survived the vast flux of Ice Age rhythms, hunting and building shelters. They had Europe to themselves until about 45,000 years ago, when modern humans arrived from Africa.”
Quote from myself:
“Neanderthols originated in Africa in the same sense that humans did.”
Quote from Nitpicking:
“No, neanderthals originated in Europe, presumably from Homo erectus ancestry. Really. Look it up.”
Since the discussion was about the possibility of Neanderthal genes having remained in the present day populations of either Africa or the rest of the world, I don’t get the nit that’s supposedly been picked here.
Roy, There are many genes that humans and Neanderthal share derived from their common ancestors. There are many genes that humans share with other mammals also derived from common ancestors.
Shared genes from a common ancestor don’t address questions of recent interbreeding. I thought we were discussing the possibility of humans and Neanderthals interbreeding, not the presence of shared genes from common ancestors.
Humans and Neanderthal may have been similar enough that interbreeding was possible. Even then, it may or may not have happened. It may have happened and all descendants of Neanderthals have died without reproducing in which case there would be no uniquely Neanderthal genes in the present human gene pool.
The references that I cited were to evidence that the interbreeding more likely than not DID happen – and to evidence that there WERE uniquely Neanderthal genes in the present gene pool.
These references are not to some pseudoscientific source – quite the contrary. But so far, no-one seems interested in dealing directly with what may be counter to the thrust of the original post.
That’s not, or at least shouldn’t be, my problem, as I made an observation, not an assertion of it’s accuracy (although such an inference could doubtless be drawn). To find some alleged fault with the semantics of my commentary misses the point completely – that there is evidence from at least one reputable source that runs counter to the assertions in this post.
Attacking the messenger instead of the message – isn’t that one of the fallacies that we’re supposed to pay heed to here?
There are numerous ways in which experienced interrogators look for relevant information in a subject’s memory that he will have been unable to forget, or in the alternative, will be unable to accurately remember.
These various tools mentioned should be used as a stopgap for the inexperienced. After that, they mostly tend to get in the way of the pattern recognition that the experienced agents will have come to rely on.
Oops, I posted the above under the wrong topic.
Roy, there is evidence that one variant of microcephalin has a fairly recent origin. There doesn’t seem to be any evidence specifically linking that to Neanderthals. The loss of microcephalin does cause profound microcephaly. It does not seem that variants of microcephalin are related to regulation of normal brain size.
I think the early suggestions that microcephalin was related to brain size and was derived from Neanderthals was quite speculative and seems to have not been verified. It seems like all it has going for it was the time association. If when the Neanderthal genome is sequenced they find the now more common variant of microcephalin, that may increase the likelihood of gene flow from Neanderthal to human. But the gene flow could have been the other way, the microcephalin variant may have occurred in the human line and then been transferred to Neanderthal.
Evans, P. D., N. Mekel-Bobrov, E. J. Vallender. R. R. Hudson, and B. T. Lahn, 2006,. Evidence that the adaptive allele of the brain size gene microcephalin introgressed into Homo sapiens from an archaic Homo lineage. Proc Natl Acad Sci USA 103 (48):18178-83
Roy, I have read that paper. Unfortunately microcephalin doesn’t regulate brain size. Complete loss of it causes pathologically smaller brains, but that does not mean that the normal gene “regulates” brain size.
We’re not talking specifically about brain size, we’re talking (or at least I am) about genes thought to be from neanderthals having apparently replaced similarly functioning genes used, and still used, by and from humans. The allegedly wholesale replacement seems to have been based on their relative utility.
A further point being made was that rather than having completely died out, they had left their mark as part of the hybrid that all humans are, as well as virtually all other species of life.
The notion put forth that we are still here and they are not is a bit silly if you consider that all of us who are here are a combination or hybridization of an unknown number of ancestral species. It may be even more silly to propose that somehow we have won over this particular species, if it still contributes to the usefulness of arguably our most important apparatus.
I have studied the history and evolution of that anthropomorphic cartoon, Neanderthal with an anthropological fascination for quite a few years..
What is interesting is that Neandertal is a Contemporary carnivorous Ape.
There have been many interesting changes over the years in the “image” from the Missing Link, to Venerated Ancestor ..shaved, dressed and promoted like a Comic Book Hero..transformed into an adolescent sexual fantasy in Clan of the Cave Bear..and now…the sad truth emerges again..This carnivorous ape shares 99.99999% of our genes but that was said about Chimpanzees a few years back.
To put that in perspective..I believe that Chimps and Neanderthal share 96% of our genome. Dogs share 90%.
Down Syndrome is change of One Gene.
Now..it is very amusing to see the Scramble to save this Disney character..Notice all the cutesy articles and documentaries featuring Neanderthal babies and their “human characteristic …damage control on the DNA testing..
It is an interesting study of Humans..to watch the invention and evolution of this anthropomorphic Cartoon..the creation of popular mythology masquerading as “science.”