Editor’s Note: This is a guest post by David Batdorf, a Sasquatch enthusiast that is interested in taking an anthropological, bird's-eye-view of the phenomenon and an advocate for species protection. Basically, he's a Bigfoot nerd.
In my last two posts, Sasquatch: Human vs Ape and The Ambiguous Gigantopithecus, I discussed my opinions, as to the likely origins of Sasquatch. I'd like to discuss the topic further utilizing what is known about protohuman migrations, periodic glaciation and the appearance of land bridges.
I will attempt to build a hypothetical model of the potential origin of the Sasquatch, identify which common ancestor we most likely share, offer suggestions for how they got to North America and when that migration could have occurred.
NOTE: I will focus on the Bering Land Bridge. However, I would like to point out that, similarly, the Sumatran Land Bridge is affected by the same rise and retreat of the oceans, offering access to the islands and in some cases, Australia...
The difference between; "Ice Ages" and "Periods of Glaciation"
Most people refer to the most recent peak of extreme glaciation, as the last "Ice Age". The last glacial maximum or peak, in which, the first modern humans crossed the Bering land bridge, or Beringia, occurred 10,000 - 14,000 years ago. The Current Ice Age, also known as, Pleistocene Glaciation, Quaternary Glaciation or simply, "The Ice Age", has actually been underway for 2.58 million years. During this ice age, there have been several glacial periods and interglacial periods. Glacial peaks, known as a "glacial maximums", occur within glacial periods. Periods of glaciation, their peaks and interglacial periods are calculated by measuring the C02 levels in sediments and rocks, then inferring the amount of ice present and temperature changes.
Glaciers, being comprised of compacted snow, are usually formed on high mountains that collect precipitating clouds against their peaks. They slowly and powerfully flow like rivers to lower elevations, shaping the land as they go. It is this inland entrapment of water, that at times of extreme glaciation is over a mile thick, that leads to decreased sea levels and thus, the emergence of land bridges.
At our most recent glacial maximum, the Beringia land bridge was likely one thousand miles, from North to South, or roughly the distance from Seattle to San Francisco, spanned between Alaska and Siberia and not covered in ice, as many would imagine. It was a lush forest environment, much like the Alaskan and Canadian coastline and interior of today. To many of those who inhabited the region, Beringia would have been a seemingly endless, bountiful refuge as the glaciers encroached from the mountains on either side.
Narrowing the Timeline
I choose the development of bipedalism as a precursory point to divergence of modern humans and Sasquatch. If this occurred 4.75 million years ago and the period of Quaternary Glaciation began 2.58 million years ago, we can cut the amount of time we need to look at for the Sasquatch crossing to America nearly, in half.
Glacial maximums and the extremes to which glaciation occurred have been measured, dated and named, within the last Ice Age. The periods of glaciation, from the most recent to oldest with glacial peaks extreme enough to open the land bridge are: Wisconsin or Wurm; Illinois or Riss; Kansasian or Mindel; and Nebraska or Guns. Prior to Nebraska, at about 1 million years ago, there were no glacial maximums that exceed our current level of ice, today and would likely have left Beringia underwater.
Within each these named periods are multiple glacial peaks or maximums. The third peak of the Wisconsin period is where modern people from Siberia came to America 10,000-14,000 years ago. It spans the shift from the Pleistocene to the Halocene Epoch and is still in recession.
NOTE: Pleistocene Mammalian Gigantism has long been a theory of why Sasquatch is so large. In my hypothetical model, if Sasquatch shares common ancestry with us at an overall maximum of 4.75 million years ago and a first potential crossing at 1 million years ago, this gives Sasquatch 3.75 million years of evolution to adapt to a life in the Northern coniferous forest. More than enough time to do so, if only a fraction of that time. Many of those years could have been spent reacting to pressures of other mammals becoming giants and may have followed suit as a predatory or a defense mechanism.
Sasquatch, Out of Africa?!
One reason that the Sasquatch' progenitors may have been on the move is due to the Miocene to Pliocene shift that occurred 5.3 million years ago, which began the deforestation and drying out of Africa. This major environmental change began prior to our specialized bipedal adaptations and is thought to have been the catalyst for the end of our progenitor’s arboreal lifestyle, by forcing us into the growing grassland. By the beginning of our Quanternary Glacial period and Pleistocene Epoch, 2.58 million years ago, human progenitors were upright, but still very different from our more modern variants.
There is much evidence that the exodus from Africa may have happened much earlier than was thought, 30-40 years ago. Homo erectus, was one of the first, longest lived and the second-most widespread of our Genus (second, only to our own subspecies of H. sapiens). They were also the first candidate for the widespread, but not complete global population, for a number of reasons. They are found at 1.8 million years ago and survived, at least, to 500,000 years ago. Some say as little as 65,000 - 35,000 years ago.
Like modern humans on their way to Siberia, Homo erectus' movement from Africa to Eurasia was also controlled by climate change and glaciers, even at their tropical latitude. Sea levels, controlled by the glacial maximums, flooded and drained the rout out of Africa many times during the unimaginably-long reign of H. erectus.
Looking back over the periods of extreme glaciation, one could argue that; IF Sasquatch likely shares a common ancestor with humans, to support a bipedal primate; AND that bipedal ancestor was not our own subspecies; THEN their ancestor's exodus from Africa would have been limited to the waves of H. erectus or H. heidelbergensis that made it to East Asia. (I will explain why I feel Heidelbergensis is unlikely)
There is, of course, no evidence of Sasquatch being related to Homo erectus or Homo heidelbergensis, but there were many hominids living in Africa in the late Pleistocene... however, no other species are documented to have left for Asia, until our own subspecies did somewhere between 125,000-80,000 years ago. Anatomically modern humans appear in africa at 200,000-150,000 years ago, or over 1.5 million years after H. Erectus spread from Africa and likely, as a secondary descendant of the H. erectus that remained in Africa. Erectus has been found from Africa, to Europe, to the East Asian/Chinese coast, all the way down through Sumatra.
Why I choose Erectus
There are many popular theories involving P. bosei or Neanderthal man or H. heidelbergensis as possible origins for Sasquatch, as a surviving relic Hominin. I have personally entertained many of these hypothesis, however, through more research into these amazing species, I found them all to be unlikely.
Paranthropus bosei is out, due to a lack of evidence of ever having left their relatively small geographical niche. This is likely due to their specialized diet and adaptations and likely what lead to their demise.
Neanderthals were highly developed tool/weapon makers and users of fire. Their genetic closeness and somewhat recent, shared lineage with us makes it unlikely that these are the non technological, morphologically different Hominin that we seek.
The Homo heidelbergensis question is one that I have looked at in detail, because some pieces seem to fit. Unfortunately, the more I looked, the less likely it became. The Heidelberg Man is the likely progenitor of anatomically modern humans, the Neanderthal and arguably. Their oldest fossils have been called into question, as they may potentially be that of Erectus and the more recent fossils are said to be proto-sapiens, not Heidelbergensis. Their range was similar to that of Erectus, however, slightly smaller and much more recent. The argued beginning of their reign is 800,000 years ago, or about the same time Erectus was already in East Asia. H. heidelbergensis did not arrive in NE China until 280,000 years ago, at the earliest. This only allows them the same, reasonable access that we had to Siberia in the interglacial period before the most recent, Wisconsin glacial period. Heidelbergensis also began their evolutionary journey with the knowledge and technology of the later, more evolved and advanced Erectus, in Africa.
Homo erectus is unique, because many of the adaptations passed to modern Hominin, like brain size, complex tool making and the use of fire, were developed over their approximate 1.5 million year reign. Brain size is of particular interest, as it lead to the other cultural and technological advances associated with Homo that were passed on to the Heidelberg Man and then us, in Africa. There is an interesting correlation with brain growth and the speed of adolescent development. In the Turkana Boy fossils, we find evidence that adolescent growth was much more rapid than in our own species. This leads to less time for brain growth, similar to nonhuman apes. We find that their cranial vaults began very small in comparison to modern skulls and that their children developed much faster, probably due to environmental stresses to grow up fast. It wasn’t until around 800,000 years ago, in the time of the first transitional Heidelbergensis, that Erectus’ brain was nearing the size of a modern human.
Prior to this, there was around 1 million years of crude tool use and no concrete evidence of an ability to use, make or control fire. More interesting, still, is the fact that there is little-to-no evidence of tools even as simple as a bilateral hand-axe in Eastern Asia, prior to the coincidental appearance of Heidelbergensis, some 500,000 years after Erectus settled there. Also, Erectus does not decidedly use fire until 300,000 - 400,000 years ago, in Europe, well into the time of Heidelbergensis and possibly even Neanderthal.
When looking into the other potential candidates, I cant help but note the fact that Erectus may have crossed into the Americas as early as 350,000 years ago, but would not have been joined by more modern or evolved Hominin in China until 280,000 years ago, or 70,000 years after the potential crossing.
Did Erectus travel to Siberia and become isolated from the waves of subsequent Hominin, or were they already in the Americas and simply returned to Asia, after much evolutionary stress and divergence? Unfortunately, there is no concrete evidence that this actually occurred.
What Does This All Mean, Exactly?
This means that these early, relic humans were migrating, separating and diverging since their evolutionary debut. The H. erectus people likely gave way to Heidelbergenisis (who gave way to Neanderthal and “us”), Florensius and a host of other distinct, post-African, geographical variants, likely including the Red Deer Cave specimen and possibly the forbearers of the Denisova specimen.
Why not, Sasquatch? I would argue that this is a likely scenario, for the above and further reasons. Homo erectus is the most likely candidate to carry the traits of bipedalism to Sasquatch half-a-world-away, while maintaining a less technological lifestyle, as was seen in early East Asian finds. This also means that, in a hunt for Sasquatch fossils, we should be searching the sediment at less than, but a maximum of, 1.8 million years and that Sasquatch divergence from us is less than that total amount of time. Probably MUCH less.
I am not suggesting that Sasquatch is Homo erectus. My hypothesis is that Sasquatch was, like so many other Hominin, preceded by Homo erectus and became their own specific variant. The obvious conclusion in this model, therefore, would be that Sasquatch is of the Genus Homo, so technically, a human... yeah, I went there. Are you surprised?!
Now, Back to Beringia!
If we know that H. erectus was in China by about 780,000-680,000 years ago, we could assume that they may have made it farther North, as this was during an extremely long interglacial period and routs would have been open and very inviting, by today's standards. Beringia would not be potentially open again until the Mindel/Kansasian period, about 350,000-250,000 years ago. This would be the first potential crossing in this model. It is likely that H. erectus was living in East Asia long before the documented fossil find and had access to the earlier, deep glacial peaks, however, there is no evidence to support such claims, so I default to the following period.
We know that the mammalian megafauna had been migrating from Asia to N. America for some time, by 350,000 years ago. H. Erectus, being a mammal eater, would likely have followed his quarry, just as the Native American ancestors did. This is, of course, assuming that they were able to adapt to the climate.
For Erectus, this would have been a test in evolution, rather than our anatomically modern ancestor's ingenuity and environmental manipulation. Like other mammals of the time, thick coats and a gigantic stature would have done the trick to conserve heat and make use of available calories, as well as offer protection from enlarged prey.
If these natural occurring adaptations took place over the course of a minimum of 380,000-480,000 years (divergence between modern human and Neandethal has been dated at 500,000 years), is it possible that Sasquatch was a new and highly adapted variant on Erectus that crossed into America at a maximum of 350,000 years ago? Was that group separated from the Almas and Yeti of Asia by the rising oceans in Beringia? Were the subsequent openings of Beringia and meetings between the cutoff cousins an explanation for the variations seen in different areas in Asia and N. America?
If you take divergent evolution into account, look at what we have become and what the first H. erectus were and imagine something with a completely different set of climate and habitat needs... AND the unimaginably-long timeframe... maybe, Sasquatch is not so far fetched. Future Siberian fossil finds of H. erectus could potentially answer many, longstanding questions... this, I feel, is the missing piece to the puzzle. Siberia has produced more preserved specimen (Mammoth, etc...) than Alaska.
In Conclusion
For Sasquatch to exist as a bipedal North American Hominid, there has to be a Hominid that transported the traits of bipedalism from Africa to Siberia and then on to the Americas. If that Hominid was not a Homo sapiens subspecies or other post-African cousins, which I find unlikely, then it must have roots in an earlier, widespread Hominid.
Because of the dispersal of fossils in the scientific record, I suggest that the most likely candidate is the prolific creator of Homo species, the well traveled and diverse, Homo erectus.
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