Essay Web Blog

I happened across this site, which belongs to Danny Vendramini, a TV producer and scriptwriter, with an interest in evolutionary biology.

Neanderthal face reconstructed by Vendramini, Copyright themandus.org

He has written a book called “Them and Us”, in which he propounds the hypothesis that Neanderthals were:

• Very different looking from most modern representations – much uglier, hairier, and far less human-like.
• That they were brutal, intelligent, tool-using predators, who preyed upon modern man in the areas where they came in contact, specifically, the Levant.
• That being the prey of Neanderthals was the most important factor in human evolution, and that it was responsible for the flowering of art and sculpture, the technological innovations in the tool making industry, perhaps even the flowering of language – all of which happened around 40,000 to 50,000 years ago.
• And not only that, it was responsible for the evolution of the human body type, including features that distinguish us from other apes, such as decreased hairiness, the development of a prominent and protruding nose, different body posture and gait, etc.
• Finally, he lists a whole range of human behavioral traits, such as preference for symmetrical faces, fear of the dark, abominable snowman myths across various cultures, etc. as some sort of racial memory of Neanderthals, whom we fear and despise, because they preyed upon us.

Now at first read, this appears to be the work of a misguided though enthusiastic kook. He seems to have no formal qualifications in biology or paleo-anthropology, and is self-taught. He makes the first few chapters of his book available online, and from a quick read, he seems very dismissive of arguments that run counter to his thesis, for example, the loss of body hair in Homo sapiens. He mentions other theories, such as the thermoregulation during the transition from forest living to life on the savannah, but he dismisses them so hastily that it looks like he doesn’t really understand them all too well. Some of the examples he gives (such as big cats are predators, and some of them live in hot climates, why didn’t they lose their hair?) have reasonable answers in the literature, but he makes no mention of them. Instead, he pushes his theory, that we lost body hair because of sexual selection – we didn’t want to look like those ugly, murderous Neanderthals – it became a taboo to look like them.

Profile reconstruction of Neanderthal face, Copyright themandus.org.

Superficially, some of this may make sense. We certainly can’t rule out the role of sexual selection in the loss of body hair. But making the jump from “might be possible in a mundane way” to “it was a response to Neanderthal predation” is a very long stretch. He does this in many, many different areas, not just body hair.

Now I understand that he offers this as a hypothesis. He is not saying this is how it happened, just that this is how it might have happened. Which is fine, but the supporting evidence is very thin. Further, in his enthusiasm to bring in every possible argument to bear, he adds so much speculative and flimsy stuff that it makes it seem like he can’t distinguish between science and fantasy. To name a few, he finds some supposedly “universal” human traits such as xenophobia, preference for bathing and cleanliness, loyalty to the group, self-sacrifice, patriarchy, aggression, and many more, and ties them all into some imagined “prey psychology”, which developed as a result of humans being the victims of Neanderthals.

To be fair, he is not alone in this. Many so called “evolutionary psychologists”, or evolutionary biologists in general, make sweeping generalizations and assumptions, based on the flimsiest evidence. To me, this is an example of science turning into social narrative, the trivialization of science. You don’t need rigor and reasoning based on solid evidence, you don’t need to be cautious, to make no claim beyond the evidence – all you need to do is to tell a good story, preferably sensational enough to get picked up by the popular press, and give you your 15 minutes of fame.

Neanderthal with spear, Copyright themandus.org.

Part of it is the problem of generalists versus specialists. Evolutionary biologists or evolutionary psychologists (*shudder*) are generalists, tying together a lot of details from anthropology, genetics, sociology, psychology, etc. to make some broad claim. But in doing so, they often lack the specialized knowledge of each individual field – they lack sufficient knowledge to not over-generalize, and sometimes end up making silly blunders. They tend to trivialize and gloss over problems that are ambiguous and not resolved, picking the interpretation that favors their own theory, often not realizing that the foundation is very shaky.

And then there are those who disconnect with reality altogether, like Vendramini, when he goes off about connecting “fear of the dark” to nocturnal predation by Neanderthals or similar arguments. The pity is that he doesn’t seem to realize what he’s doing. In trying to add weight to his arguments, he is throwing in every last thing he can think of. And so he’s mixing in things that have some weight and credibility (like, we don’t really know exactly what Neanderthals looked like, perhaps they were more ape like than modern representations; or we don’t know exactly what human-Neanderthal interactions were like, there may well have been violence), with things that are utter nonsense, such as fear of the dark. So the good stuff gets mixed with the bad, and taints everything as trash. Further, it creates a bad impression of the writer, in that he doesn’t seem to be able to distinguish science from fantasy.

To top it all, he really appears serious about this airy-fairy stuff. He has another theory (and another whole website devoted to it), which propounds something he calls “teem theory”. In simple terms, the theory is that nasty stuff that happens to us and creates powerful negative impressions gets imprinted on non-coding regions of our DNA, and thus becomes heritable to future generations. This is what he uses to explain things like fear of the dark, xenophobia, etc. – that these bad experiences with homicidal Neanderthals became imprinted on our DNA, and continues to manifest in modern behavior.

That would be a whole other discussion and a whole other blurb on this blog, so I don’t want to get into it at this time. Briefly, he looks at instinctive behavior of a certain kind, such as certain animals instinctively recognizing their predators and avoiding them, concludes that such behavior must be coded into the DNA, since it’s untaught and not learned, therefore DNA must provide a mechanism for coding our fears. Such ideas ignore a whole realm of evidence, that a huge range of predator-avoidance behaviors are in fact learned, and that interpreting specific instances where they don’t appear to be learned is over-generalizing. Yes, there are instincts that are heritable, but the actual mechanism of how they work, what exactly is coded in the DNA, are very much unknown. Making it out to be something as specific as xenophobia is very imaginative, but poor science.

Neanderthal, hunting. Copyright themandus.org.

I see evolutionary biologists make similarly specific claims, that generosity and altruism are hard coded in our genes – all sorts of stuff like that. I consider it all very unlikely, an over-specification of something much broader. Perhaps what we are inclined for is social cohesiveness, being social animals, and specific instances of it are just a manifestation, they are not individually hard coded. It’s possible to take a population of rats, breed for either aggressiveness or docility, and in a very few generations end up with two distinct populations that are behaviorally very different in that respect. It’s been done. It doesn’t show anything very specific, other than that “fight” responses and aggression are more marked in one population than another, perhaps through some simple hormonal trigger. Going from that to very specific theories about brain centers dealing with aggression, or “cooperation” or something similar is not warranted by the evidence.

While I find his theory not convincing, it did make me wonder about a few things. What exactly do we know about how Neanderthals looked like? Forensic recreations based on bones have to be somewhat an exercise in guesswork, on prior knowledge. I agree with his point that they are not at all comparable to forensic recreations of humans. After all, we have a huge body of knowledge of what humans are supposed to look like, so our guesses are founded in a great deal of prior information. We don’t have a similar body of knowledge of what Neanderthals looked like, so our reconstructions may err on side of making them look too human (or conversely, less human) than they really were.

We have no casts of their soft tissues. We don’t know how hairy they were. We don’t know how much their noses protruded. We don’t know how big their eyes were, how erect their spines, how prominent their musculature. For all of these things, we make educated guesses, but some guesses are more educated than others. For example, the musculature is hinted at by the shape of the bones, the sites of attachment of various muscles to the bones. So this kind of guess can be trusted to a greater extent than say, the guess about how hairy they were, or what their skin was like, or how symmetrical their faces were.

So our picture can’t be very precise, there is some range of possibilities, within the constraints set by the bones. Just how wide that range is, I don’t know, and I wonder if they could have looked like the pictures on his web site. I don’t personally know of any physical evidence that goes against his reconstruction. Perhaps some more knowledgeable people can add to this. But it occurs to me that if Neanderthals looked sufficiently ape-ish, sufficiently non-human, it would explain why we find no evidence of human-Neanderthal interbreeding in the genomes. It would discourage (though not necessarily prevent) the two species from interbreeding.

I look forward to more information which should become available as the Neanderthal genome is fully sequenced and annotated.

This line of thought was provoked by an article I read talking about the importance of cooking food in the development of modern humans.

I’ve come across a number of articles that talk about the importance of a change in diet in human evolution. The theory is that human diet suddenly improved dramatically, and this marked increase in the availability of calories and nutrients was responsible for the growth of the brain. The improvement in diet is generally tied to either the switch from a primarily herbivorous diet to meat eating, and/or to cooking.

Both make sense in terms of calories and nutrients. Meat is certainly a more densely packed source of nutrients than plants. And cooking increases the bioavailability of nutrients, as it breaks up cell walls and structures that hinder our digestive enzymes from reaching the goodies inside cells.

Of course, this still leaves us without an actual mechanism. Evolution requires heritable changes in the genome. These happen largely by  accident, though their selection depends upon what is advantageous to survival and reproduction. At this point, we don’t know very well exactly which genes are responsible for the differences in our brains, say compared to chimpanzees. We don’t know when these changes first appeared. We don’t know what connection they have to an improved diet.

So one part of evolution, that which is related to the genomic changes responsible for our large brains, is mostly unknown to us. Therefore, I think that ideas such as the change-in-diet leading to big brains scenario, tend to ignore the unknowns and focus only on the natural selection side of evolution. They make certain assumptions, for example, that a large brain will be selected, because it enhances survival and the chance to reproduce. This can be somewhat justified if one thinks about  it (large brains, specially the growth of the forebrain is what allows us to make long range plans, analyze complex problems, etc.), and also there is fossil evidence that shows that in fact it was selected. Then there is the assumption that a large brain requires a nutrient rich diet, which can also be justified on the basis of the caloric expenditure in maintaining a large brain. A commonly offered statistic is that for a person at rest, of the amount of energy required to stay alive, the brain uses 20%, or 1/5th. The brain is obviously much less than a fifth of the body in terms of mass, yet it uses an extraordinary amount of energy, in proportion. If you keep the total mass of an organism constant, but increase the size of the brain in proportion to the rest of its body, then such an organism will require a more nutrient rich diet. In effect, you have increased its energy requirements, but have not given it bigger jaws to chew food, a bigger gut to digest it, bigger claws to hunt with, etc.

In fact, both anatomy and the fossil record show that humans became less capable of acquiring food as their brains grew, if we look solely at such biological markers such as tooth/jaw size. Homo erectus had smaller jaws than his ancestors, which would have made it harder for him to grind foods down and extract the most energy from them. Our gut became smaller, and less capable of extracting energy from plants. Our muscles became weaker, less capable of overpowering other animals through brute strength alone.
One would think that the timing of these changes would have some correlation with our behavior or change in diet, or the control of fire (for cooking). Unfortunately, the timing is much harder to pin down. No one really knows when humans first learned to control fire. Homo erectus, with his small jaws, evolved 2 million years ago, but the evidence for the widespread use of fire by humans at this time is scanty at best. Most anthropologists don’t believe that fire was used by humans this early, at least, not in any regular, controlled manner, such as would be needed for cooking. Soft tissues don’t fossilize well, so while we can study humans and chimps today and recognize that the chimp gut is much more suited for eating raw plant material than the human gut, we don’t really know when we evolved our more carnivorous digestive systems.

This leaves a chicken versus egg conundrum. Which came first, the big brain or the adaptations to the big brain lifestyle? Which was responsible for the other? This may be a silly question on the face of it, because obviously one is useless without the other. What’s the point of having a modern jaw or gut if you don’t also have the bigger brains that give you the means for filling that gut with food? On the other hand, how do you sustain that brain and give it energy without eating a more nutrient-rich diet?

So it seems that speaking in terms of absolute causality, one thing causing the other is somewhat simplistic. They probably both happened together, one reinforcing the other, and happened gradually. We didn’t go suddenly from a chimp-sized brain to a human-sized one, as we know from the fossil record. There are many intermediate stages of the brain growing progressively larger. The change in diet, therefore, and the behavioral changes accompanying both the change in diet and the larger brain, must have happened concomitantly.

It’s interesting at this point to bring in the factor we’ve ignored all along – that there must be genomic changes that produce all the anatomical differences – jaws, teeth, gut and brains. These genomic changes also need to be accounted for, and tied into the selection mechanism. A high nutrient diet is obviously not enough; otherwise large cats such as lions and tigers would be smarter than us. They might not cook, but they eat enough high nutrient food to be able to support bigger brains. They have evolved as long as us, why didn’t they learn to cook,  why didn’t they evolve bigger brains?

This brings us back to selection, and fuzzier areas of anthropology such as social behavior and interactions, etc. We have bred dogs for a few thousand years, for example, and we have breeds of dogs today that look very different from each other. Not only is there is a difference in size and color of the fur, but there are also differences in the brain. Some breeds of dogs are smarter than others. We did this by a fairly simple process of selection – pick dogs that have the traits you want, breed them to produce a new generation, keep selecting for the desirable traits and reinforcing them through successive generations. Even with no knowledge of DNA or even Mendellian genetics, our ancestors were able to do this for dogs. We have also bred cows, pigs, goats, sheep, etc. – the modern domesticated forms of which are quite different from their wild ancestors. Not to mention the similar and parallel process of breeding food plants.

So even without postulating major and sudden changes in the genome, those which suddenly introduced a “game changer” mutation so far as the brain was concerned, it’s possible to see that humans could have become progressively smarter simply if the natural variation in smartness among a population was selectively reinforced over generations, the same way we breed dogs. Of course, this doesn’t mean that you can breed dogs to a human level of intelligence, there may well be certain required mutations, and these have to happen first. You can’t select for what doesn’t exist. But at a point where we don’t fully understand the nature of these key mutations, we can’t really talk about how essential they were. Perhaps they could happen in other species too. Perhaps there are a dozen different ways to get the same result, and if mutation “A” doesn’t happen, mutation “X” can provide the similar benefits. I’d rather not speculate about this until we have more information to speculate with.

So I think such articles (as the one referenced above, which talks about the relation of diet to human evolution) speculate about the remainder of the problem, the mutually reinforcing effect of the selection of traits which are part of the natural variability of a population, and the behavioral consequences of selecting such traits. You set a species on a certain path, on which a greater reliance on the brain cuts out some options while expanding others, and the options that are promoted require even greater brain power to work well. It’s interesting to speculate what put us on this path, why we seem to be the only species on it. What set of circumstances came together at the right time for this to happen. The drying climate and spread of grasslands, the change from an arboreal to a savannah type lifestyle, the appearance of bipedality at this critical juncture when these big new ecological niches suddenly opened up, the development of more and more hand flexibility with a greater range of movement in the opposable thumb (compared to other primates), the social interactions, etc. There were so many changes happening at roughly the same time to the same species, somewhere this set us off on a path to bigger brains.

The article that set me off on this line of thought, of course, talks about something narrower. It talks about the relationship of cooking to gender roles, the development of the male-female bond, which is marriage today. This seems less an evolutionary question than an anthropological one. The evolutionary part is the importance of cooked food in the development of our brains, which I have speculated about. The anthropology part is relating this importance to something else, namely male-female pairing. I am not qualified to speculate about the anecdotal evidence offered about some primitive societies where food is more important than marital fidelity. Nor do I have any evidence that women tended the home fires, though it seems likely if men were the hunters and spent less time at the home camp. This seems to be supported by fossil evidence, such as hunting related injuries, as well as by anthropological evidence. You can speculate that the importance of cooked food was critical enough to shape our behavior patterns in other ways, such as pair-bonding between males and females. But just because a theory seems to make sense doesn’t mean it’s true, so I guess we’ll need to see some more physical evidence before placing much value on it.

I saw a re-run of the History Channel show Journey to 10,000 BC recently. My expectations from the History Channel continue to sink as they produce low quality shows full of factual errors and outright speculation presented as fact. They have turned into the Pseudoscience Channel.

Despite the broad sweep implied by the title “10,000 BC”, the show was limited to the North American continent, completely ignoring interesting events such as the beginning of agriculture, the domestication of animals, and the first monumental stone architecture, that were happening elsewhere in the world.

The show focused on the human occupation of the North American continent. It mentioned the prevailing theory that the paleo-Indians were of Beringian origin, who migrated from Asia across a land passage over the Bering Strait, which existed at the time due to lower sea levels. The Beringian people were of Siberian stock, but the show inexplicably chose Caucasian-looking actors to portray them. This discrepancy was later cleared up when they introduced the Solutrean Hypothesis, advocated by a number of people, including Dennis Stanford of the Smithsonian Institute.

The Solutrean Hypothesis proposes that the Clovis Point Culture was of European origin, specifically, an offshoot of the Solutrean Culture in Eastern France and Spain. The Solutrean industry is characterized by pressure-flaked bifacial stone points, which appear to resemble stone points found in ancient paleo-Indian sites such as Cactus Hill in Virginia, and the later Clovis Points. The idea is that Solutrean people moved across the Atlantic to the east coast of the North American continent, across a northern passage that consisted of large masses of packed ice interspersed between land masses (Iceland, Greenland). These people “followed the seal herds”, using animal skin boats to cross the stretches of water between land masses and ice packs, and eventually made their way into the Americas. The archeological finds at Cactus Hill appear to pre-date the Clovis Culture, and are inferred to be the remains of the early settlements of these Solutrean people from Europe. Sometime around 13,500 years ago, these people developed the fluted Clovis Point (an elongated Solutrean-like stone tool, with fluting at the base to allow it to better fit a spear haft), and the Clovis Culture spread across the continent.

Solutrean, Cactus Hill and Clovis Points

To support this theory, the show pointed out that most Clovis sites have been found in the Eastern US, indicating that the Clovis culture may have spread from east to west, which would be contrary to a west-to-east migration of people who had arrived via the Bering Strait and the Pacific coast.

Although the show mentioned a couple of times that this theory was “controversial”, it failed to mention the large body of evidence against it, nor did it even attempt to offer equal time to any of a number of mainstream archeologists and anthropologists who oppose it. It continued to represent the paleo-Indians through Caucasian actors, going so far as to present a hypothetical confrontation between these Caucasians, and the Asian Siberian people who arrived through the Bering passage. The confrontation ends in a fight, with the implication being that the Asians possibly wiped out these early Europeans. There is a lot more about the end of the Clovis culture, with the concomitant disappearance of the native mega fauna with the climate cooling of the Younger Dryas, a hypothesis that this may have been caused or aided by an asteroid impact, etc.

While controversy sells, this account shortchanges the truth in many ways. The Solutrean hypothesis is not widely accepted, and is contradicted by several lines of evidence. Its support rests upon a similarity between the appearance of Solutrean and Cactus Hill / Clovis points. Such similarities may result in a number of ways. Tools develop to fulfill certain functions, and a bifacial pointed tool that can be attached to a wooden stick to form is spear is singularly handy for bringing down large game, which both the Solutreans and the Clovis Point people did. After all, there are only so many ways you can design a hammer, or a knife. If the tool is to be used for a particular purpose, its design will naturally lead to a form suitable to that function, whether done by Solutreans in France, or paleo-Indians in the Americas.

There are a number of unexplained factors to consider. How did these Solutrean people cross the Atlantic? Proponents of this hypothesis believe they used animal skin boats. No evidence of such a boat building Solutrean culture has ever been found, but the proponents claim it could easily have been lost, since you would expect to find its remains along coastal regions, which have long since been submerged as the ice melted. There is a distinct lack of other Solutrean features in the Clovis Point people, other than these bifacial stone points. There is an unexplained 2,000 – 3,000 year gap between the end of the Solutrean industry in Europe, and the emergence of Solutrean-type tools in the Americas. Where were these people then? Where is the evidence that they kept this industry alive in the meantime?

There is little evidence of any European inheritance dating to this period in modern native American populations. Earlier studies showed a significant prevalence of haplogroup X in the mitochondrial DNA of native Americans. Haplogroup X is found predominantly in west Asia and Europe. However, the latest research shows that all current native American populations are likely descended from a single group in Berengia, which took part in a series of migrations along the Pacific coastal route into the Americas, between 18,000 to 15,000 years ago. These are, in fact, the pre-Clovis people.

Haplogroups A–D are also frequent in Asia, suggesting a northeastern Asian origin of these lineages. However, the differential pattern of distribution and frequency of haplogroup X led some to suggest that it may represent an independent migration to the Americas. Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple migration models.

- Fagundis, et al. Amer. J. Human Genetics, 82: 1-10, March 2008

None of this was mentioned in the documentary. Nor was there any mention of the range of pre-Clovis sites that have been found along the Pacific route (such as the 14,300 year old human coprolite found in a cave in Oregon, or the Monte Verde site in Chile, dated to 14,500 years old). The Monte Verde II site is the oldest reliably dated human settlement in the Americas, at least 1,000 years older than any other. If the paleo-Indians could reach and settle a point thousands of kilometers farther from their point of entry into the Americas than Cactus Hill, or the Clovis sites along the east coast, why could they not have reached the east coast sites, which are much closer? Just because we have found more Clovis sites along the east coast does not imply an eastern origin to the people. There is every reason to believe that there were pre-Clovis people scattered throughout the continent, and that these people could easily have been descendants of paleo-Indians from Berengia. Clovis point is simply a tool making industry, and it says little about the nature or origin of the people who developed it.

Presenting such a one-sided account of a controversial hypothesis which has found little acceptance in academia does a disservice to the audience. Most people who watch the History Channel are not experts in this field, and will tend to accept it at face value. When the bulk of the program consists of a couple of these controversial scientists presenting their theory, interspersed with shots of Caucasian actors stalking mammoths, the average viewer is left with the impression that this is in fact what happened.

The show had numerous other factual errors. Twice, the narrator claimed that the Columbian mammoth hunted by these Caucasians was the “largest land animal since the dinosaurs”. This is completely untrue. Apparently, they forgot the indricotheres. Even worse, they ignored other larger mammoths, such as the Imperial mammoth that lived right here in the Americas, or the even larger Sungari mammoth or Steppe mammoth from Siberia. Surely they could have avoided such mistakes if they had just run the script by even one expert. There were numerous instances of cheap shoddy work. The CG effects were horrible. The mammoths look like something out of a cheap computer game.

Having a low budget is not a crime, but distorting science to present controversial theories that are probably wrong as fact is unforgivable for a science program. It only supports my contention that the History channel is all about entertainment, and has little to do with facts.