Why bigfoot cannot be Gigantopithecus

Gigantopithecus blackii. The extinct apes in the genus Gigantopithecus were close relatives of the two orangutan species. This model best represents Gigantopithecus blackii as being something like a giant orangutan.

One of my favorite topics is cryptozoology, but as much as I like it, I would be the first to tell you that it’s very much a pseudoscience.

Yeah. If you follow Sir Karl Popper’s definition that exists between a science and a pseudoscience, the most important distinguishing criterion is that of falsifiability.  That means, when we come up with a hypothesis, can we refute through the evidence at hand.

If you are to say your hypothesis is that bigfoot exists, then you’ve got a problem.

It is next to impossible to prove that something does not exist.

No one can prove that bigfoot does not exist.

All we can ever do is prove that it does.

And that’s a big problem scientifically.

The default position has to be that bigfoot does not exist until convincing evidence is brought forward, and it is only when that evidence is brought forward that we can actually ask scientific questions– because then we have material which which we can examine using the scientific method.

All that science can do with bigfoot and other cryptozoological creatures is postulate about how likely it is for one of these animals to exist. Science uses a very important law called parsimony.

Parsimony is very simply a way of thinking through potential hypotheses to see whether they might be worth exploring or whether potential explanations are likely.

All that parsimony does is reduce the amount of assumptions within a model.  The more assumptions one has in a model, the more likely one is to be wrong.  The goal is to develop explanations that have the fewest assumptions possible, for fewer assumptions means a greater likelihood of being correct.

Now how does bigfoot fit with the law of parsimony?

Not very well.

The bulk of the literature on bigfoot or sasquatch says that bigfoot is a gigantic, bipedal ape that lives throughout North America and likely derives from Gigantopithecus blackii, an extinct ape that once lived in southern China and Southeast Asia.  This extinct ape supposedly crossed the Bering Land Bridge during the last Ice Age and then came to inhabit much of North America.  This theory was first promulgated by the late Grover Krantz, a professor of anthropology at Washington State University.  This theory is the one that has the most traction with bigfoot researchers and enthusiasts, although there are other theories about what it might be (which shall be discussed later in this post).

Now, let’s think about the assumptions that exist within this model:

1. Gigantopithecus was bipedal.
2. Gigantopithecus crossed the Bering Land Bridge.
3. Gigantopithecus can live in a wide range of habitats in North America, even though it lived only bamboo forests in Asia.
4. Something that big can do an excellent job of hiding itself in a technologically advanced society, which has camera phones and digital cameras everywhere and which has access to the best camera trap technology in the world.

Let’s take the first assumption.

I think the best analysis I’ve yet seen on the purported bipedalism of Gigantopithecus is by Donald Prothero of the Skepticblog.

First of all, we need to understand what Gigantopithecus actually was.

Do we have evidence from the fossil record to suggest that Gigantopithecus was a biped?

The fossil evidence of Gigantopithecus blackii is quite weak. All we have are about 1,300 isolated teeth three lower jaws.

The original Gigantopithecus blacki specimens were found in some Chinese cave deposits, first discovered in the 1920s. They include teeth and a complete lower jaw. Unfortunately, there are no other skeletal parts known from this mysterious gigantic ape, despite decades of searching by the large number of Chinese paleontologists who now work on the deposits. More recently, Ciochon has revisited this region, and found more specimens of Gigantopithecus. He did so by shifting his focus to cave deposits in North Vietnam, which are unspoiled by the fossil poachers who robbed the Chinese caves to supply “dragon bones” for apothecaries to grind up into Chinese “medicine”. Still, even after more than 75 years since the first tooth was found, we still have only three lower jaws and about 1300 isolated teeth of this mysterious primate. There is also a second species, Gigantopithecus giganteus, from India, which (despite its name) is about half the size of Gigantopithecus blacki. A third species, Gigantopithecus bilaspurensis, comes from much older beds (6 to 9 million years old) in India, suggesting that the Gigantopithecus line goes back to at least 9 million years ago and the evolutionary radiation of early apes such as the dryopithecines (Ciochon, 1991).

Because we have only the lower jaws to go on, it’s hard to reliably estimate the size of the entire creature. Ciochon et al. (1990a) estimated that it was about 10 feet (3 m) tall and weighed about 1200 pounds. Simons and Ettel (1970) suggest it was proportioned like more like a gorilla, standing about 9 feet tall and weighing about 900 pounds. Either way, it was the largest primate that ever lived, immensely larger than a gorilla (the largest living primate), or even the biggest human giants.

What we do have of Gigantopithecus are the heavily built jaws with huge teeth, especially the molars, which have very thick enamel. Both the molars and the cheek teeth in front of them (the premolars) are very broad and low-crowned, often with their entire occlusal surface ground down flat, suggesting that these creatures ate a very tough, gritty diet. Ciochon et al. (1990b) used microscopic analysis of wear facets on the tooth enamel, and the presence of phytolith fossils from plants, showed that the Chinese apes ate mostly bamboo, as does the living giant panda.

Gigantopithecus had lived in Asia since at least the middle Miocene, about 9 million years ago, and were found mostly in eastern Asia during the Ice Ages. Careful dating of cave deposits in Vietnam which yield both Gigantopithecus and Homo erectus showed that early humans invaded China about 800,000 years ago, and that Gigantopithecus died out about half a million years later, around 300,000 years ago (Ciochon et al., 1996). Although this certainly disproves the idea that Homo erectus immediately killed off its distant cousin, there are also other possible factors, including competition with giant pandas which competed for bamboo, and also the fact that bamboo suffers from huge die-offs every 20-60 years, which may have stressed the ape population and made them more vulnerable to competition from pandas or people.

So Gigantopithecus blackii was an Asian ape that was most closely related to the orangutan that had roughly the same ecological niche as the modern giant panda.

The giant panda is a highly specialized species. Its range is entirely confined to bamboo forests, and it has always been found only there.

The giant panda is a bear, and all bears initially started out as generalists.  The same can likely be said of the ancestral apes, which were once widespread through Asia and Africa. Like the panda, the Gigantopithecus specialized from a generalist ancestor.

Specialization means that the giant panda can only be found in bamboo forests, which also means that the giant panda could never have colonized North America.  To get to North America across the Bering Land Bridge, the panda would have to be able to exist north of where bamboo forests grow in Asia.

That’s not going to happen.

So just as we don’t have giant pandas in North America, we probably aren’t going to have Gigantopithecus.

The next problem is that we cannot figure out how Gigantopithecus walked by examining three jaw bones. Grover Krantz thought that the shape of the jawbones at the back suggested that the the jaw was held in the same position as a biped, but you still would need to have a full skull in order to figure this out.

However, we don’t have a full skull.

And without a full skull, we need to pare back our assumptions a bit, and consider that it is most likely that Gigantopithecus was a fist walker– just like its cousins, the two living species of orangutan– or a knuckle-walker, like the bonobo, the chimpanzee, and the gorilla.

Bipedalism is a very unusual trait. To develop this form of locomotion, our ancestors had to evolve an entirely different kind of foot, which existed first in the Australopithecines. This form of locomotion has only ever been proven to exist within African ape species that descend from Australopithecines, which includes all the various species in the human lineage and the apes known as Paranthropus.

This trait has not been confirmed in any Asian ape species, living or extinct.

So if bigfoot were Gigantopithecus, it would have had to have evolved bipedalism in parallel with this African ape lineage to which we belong.

Now, that might be possible, but one would expect the bipedalism of bigfoot to quite different from that of humans. Parallel and convergent evolution do not use the same genetic mechanisms or anatomical structures to produce the same phenotype, but nearly every depiction and description of bigfoot show it to be bipedal in exactly the same way humans are.

That’s very hard to accept from an evolutionary perspective.

This is further made dubious with the claims that bigfoot is much larger than any human. If an animal of that size were bipedal, the simple mechanics of its locomotion would have to be very different from that of our own. Our legs and feet haven’t evolved to hold over a thousand pounds of weight erect.

And the feet are another problem, if bigfoot were Gigantopithecus, why does it almost always have feet that are almost exactly like scaled-up human feet? Human feet are so different from other apes (which look like hands) that it would be one of the greatest examples of parallel evolution for the Gigantopithecus to have evolved feet that are that much like ours. Never mind that some purported bigfoot tracks in Florida, Louisiana, and Texas, depict four-toed tracks that look suspiciously like those of alligators.

Then, there is the whole fossil record problem. There simply is no evidence of any kind of ape in Northeast Asia, except for humans. And there is no evidence for any ape species anywhere in North America. Now, there are primates native to North America. Yes, but you have to remember that Mexico and Central America are part of North America, and there are New World monkeys living there.

No apes, except for people.

Furthermore, one would think that with so many camera traps being installed in North America for scientists to study wildlife and for hunters to plot out deer movements, we’d catch a glimpse of a sasquatch once in a while. It hasn’t happened. Many bigfoot researchers will say that bigfoot is too smart to be photographed by one of the devices, and it’s not like humans have ever been caught on film with a camera trap. Oh wait, they have.

So for the assumptions behind whether Gigantopithecus is bigfoot, it seems that they may be too much to fit the law of parsimony.

These assumptions don’t hold up under careful scrutiny of the evidence we already have and what we already know about animals that we know exist.

Now there are two other theories about what bigfoot might be.

One of these is the Paranthropus hypothesis.

This one originated with Loren Coleman, and it is a little bit better at paring away the assumptions than the Gigantopithecus hypothesis.

As I noted earlier, Paranthropus was a genus of bipedal apes that evolved in Africa from the Australopithecines, which is the same root stock from which we descend.

If bigfoot is Paranthropus, it would explain why the bipedal locomotion is so similar to ours and also why the feet are so similar.

However, there are just as many problems with this hypothesis.

One of the biggest is we have no evidence of Paranthropus species existing outside of Africa. Africa is a long way from Washington State and Texas.

Further, Paranthropus was much smaller than bigfoot. The biggest individuals in the genus were only four and half feet tall.  Like Gigantopithecus, it was a highly specialized ape, believed to have lived on grubs and roots. Our direct ancestors, which were also derived from the Australopithecus lineage, had a much more varied diet, which allowed our ancestor to thrive during conditions of drought.

A specialized diet means that Paranthropus, like Gigantopithecus, was unable to become very widespread.

Neither of these animals could fit the descriptions of bigfoot, which come from virtually every part of the United States and Canada.

So Paranthropus also has too many assumptions.

Then, there is another hypothesis– one that isn’t often discussed but one that works better than the other two.

This one is that bigfoot is actually a human species.

Now, this sounds a big moonbattish.

But this hypothesis actually reduces the number of assumptions from either the Gigantopithecus hypothesis and the Paranthropus hypothesis.

We have an example of offshoot of Homo erectus that became much smaller than its ancestor. Remains of diminutive hominins were found on the Indonesia island of Flores. These remains were dated to between 95,000 and 17,000 years ago, and while some scientists contend they represent nothing more than unusually small people, the bulk of the evidence suggest that it was a unique species of human that became smaller through insular dwarfism.

Perhaps bigfoot is an offshoot of an early human lineage that became larger when it migrated into North America. Perhaps instead of developing fire, bigfoot evolved very thick fur to deal with the cold.  It would also suggest that the furriness of the sasquatch in the Patterson Film is distinct from the fur we see on other great apes. Great apes don’t have thick fur around their mammary glands, but if sasquatch evolved its furry coat from an entirely different evolutionary path than the other great apes, it would make a lot more sense that it evolved from the human lineage, which has lost most of its hair.

If bigfoot were in the human lineage, it would make sense that it would have had bipedalism and the very human-like feet. The breasts of the purported sasquatch in the Patterson Film are much more in keeping with those of a female human. Other great apes don’t have fatty breasts, but whatever is in the film clearly does. Apes only have breasts when they are nursing, and there is no evidence the Patterson film creature had a baby.

It would be very unusual for an ape to have evolved so many distinctly human traits in parallel, so if bigfoot is anything, it is most likely in the human lineage.

This hypothesis is not widely accepted in the bigfoot researchers community, which is paradigmatically attached to the animal being Gigantopithecus. One of the reasons for not considering bigfoot to be part of the human lineage is really quite simple: the bulk of bigfoot researchers want to kill one.

I remember watching the old In Search of… series (in reruns), and I distinctly remember the bigfoot episode. There was an debate about whether one should be killed in the name of science.  One researcher said that it would be immoral to kill one, because a bigfoot is a part of the human lineage.   If bigfoot is part of the human lineage, then it would have constitutional rights in the United States. Killing one would be homicide.

Esteban Sarmiento, a functional anatomist and primatologist, echoed some very similar views on the possibility of what bigfoot might be. Sarmiento is a bigfoot skeptic and pretty good scientist. He contends that bigfoot could not possibly be an ape. However, from his description of the evidence, he appears to be imply that bigfoot, if it exists, must be in the human lineage.

Sarmiento, though, wouldn’t exactly address the question of whether Bigfoot exists or whether he believes the tales about wild, hairy beasts that have drifted out of dark, wooded river bottoms and foggy rain forests for decades. What Sarmiento did say, though, is that, based on his studies of great apes in Africa, Sumatra and Borneo, whatever Bigfoot is, he’s not an ape.

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“A great ape (chimp, gorilla or orangutuan) can’t do this. I guarantee there’s no great ape that can do this,” Sarmiento says, pointing to the frame in the film when the creature turns in full stride to look over its shoulder at the camera. “A gorilla couldn’t do this. It can’t turn its head. An ape would have to stop and turn around to look at the camera.” Apes can walk on two legs, he said, but not with the stride and gait the Patterson Bigfoot uses. That’s a human trait.

“And the breast is covered in hair. Gorillas don’t have hair on their breasts. Apes only have breasts if they’re nursing, but there’s no baby in the film,” Sarmiento said. “Females usually have a baby around, and I don’t think it would leave and not take the baby.” Sarmiento added that the bottom of the Bigfoot’s foot in the film isn’t an ape’s foot with an opposable toe and even noted that it looks somewhat like a padded house shoe.

So what is it? What does the film show? “If I can’t show it either way, why would I make the call,” Saremiento said. “If it’s real it has to be a whole new species. Is it a man in a monkey suit? I don’t know. If I said that and it turned out not to be, then I’d look stupid.”

Sarmiento was addressing a bigfoot research convention when he made these remarks, and he’s a very highly qualified scientist trying to discuss things with people who “believe.” Sarmiento knows that he can’t say anything definitive about bigfoot, other than what the law of parsimony would suggest it might be. That’s not what most people in an audience of bigfoot researchers wants to hear.

In the end, the law of parsimony, also known as Occam’s razor, requires us to pare around on this assumption. This assumption fits best with what we know about bipedalism in primates and the fossil record of the various ape species.

The problem with this hypothesis– which should be obvious to anyone with a rudimentary understanding of human evolution– is there is no evidence of any other human species living in the New World, other than modern humans. There is copious evidence of virtually all other human species in the Old World, but not a single piece of evidence of any other kind of human in the Americas.

So the best pared-back potential hypothesis also has a major flaw.

And with none of these assumptions fitting the evidence that already exists, the best assumption is that bigfoot doesn’t exist as a biological entity.

However, this assumption cannot even be raised to a hypothesis. One cannot prove that something doesn’t exist.  It simply not falsifiable.

Now, does the law of parsimony always work?

Of course not.

Sometimes, evidence is revealed that is totally unexpected– which leads to the rewriting of everything that we thought we knew about a particular subject.

But until someone produces a bigfoot body, we’ve got to go with the assumption that it doesn’t exist.

None of these potential hypotheses fits with what we already know. And all require us to make assumptions that are either quite faulty or potentially quite faulty.

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I hope my more science literate readers will forgive my cavalier usage of the terms hypothesis and theory in this post.  I fully understand that we are operating within a pseudoscience here, and none of these hypotheses is actually a good scientific one, which is why I am remiss to come up with a term other than how a layperson would understand the terms “theory” and “hypothesis.” They are sort of interchangeable in the American vernacular.