New Evidence Suggests Early Humans HIBERNATED In Caves, Like Bears

Did Stone Age Neanderthals wait out the coldest days of winter snuggled up safely beneath furs deep inside caves, in a state of suspended animation for months while the winds raged, and the snow piled up outside? Recently discovered evidence suggests that this may very well have happened, at least in areas of Europe that suffered from extreme cold during the Pleistocene Epoch, which is when these rugged, hardy ancestors of modern humans occupied the earth. Human hibernation is a new theory and recent evidence seems to prove it to be true. When analyzing 430,000-year-old fossilized bones unearthed at an archaeological site called Atapuerca in northern Spain, the scientists found evidence of lesions and other damage that is consistent with similar markings and deformities found on the remains of hibernating animals. This type of damage is known to be caused (at least in some cases) by interruptions in cycles of bone growth, which is an effect caused by the slowing of metabolism associated with states of hibernation. Clearly, human hibernation is here to stay as a plausible theory.

These extraordinary findings were introduced in the December edition of the peer reviewed journal L’Antrhopoligie, by Spanish paleoanthropologist Juan-Luis Arguaga, who leads the Atapuerca Foundation, and his colleague Antonis Bartsiokas from Democritus University in Thrace, Greece.

Exposed to the harshest conditions imaginable on the unforgiving Iberian tundra, desperate early humans may have had no choice but to retreat into caves and hibernate. In this dark and cold environment, they may have lapsed into “metabolic states that helped them survive for long periods of time in frigid conditions with limited supplies of food and enough stores of body fat,” Arguaga and Bartsiokas explained.

The researchers acknowledge that their speculative hypothesis sounds like “science fiction.” But they note that primitive primates, from which we all evolved directly or in parallel, are among the animals known to have hibernated. This suggests that “the genetic basis and physiology for such a hypometabolism could be preserved in many mammalian species, including humans.”

430,000-year-old fossilized human bones unearthed at Atapuerca in northern Spain, the scientists found evidence of lesions and other damage consistent with lesions and damage found in hibernating animals. Mario modesto / CC BY-SA 3.0

Human Hibernation: Some Neanderthals Likely Hibernated

While modern human beings apparently lack the capacity to slow their metabolism far enough to reach the type of stasis associated with hibernation, this doesn’t mean our predecessors also lacked this ability. Modern humans ( Homo sapiens) did not appear in Europe until approximately 210,000 years ago, according to the latest research. This means that the bones discovered in the massive ancient burial chamber found at Atapuerca, which is known as Sima de los Huesos or the Pit of Bones, would have belonged to ancestors of modern humans, most likely Neanderthals.

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Despite their close relationship to modern humans, Neanderthals would have undoubtedly possessed some unique physiological abilities or characteristics. These abilities would be been forged by the powerful and potent crucible of evolutionary biology, which allows species to develop a broad range of adaptations that have survival value. Human hibernation falls into this range of adaptation.

Climate has always been a determining factor in evolution, and that would have been even more true 400,000 years ago. Lacking the technology to construct sturdy indoor spaces with central heating, early humans would have possessed limited means to protect themselves against the ravages of bitterly cold winters. Stone Age humans would also have been more dependent on the immediate environment to furnish them with nourishment, and that means calories could have been quite scarce for Neanderthals in the winter, when plant life was dormant and most prey animals were hibernating.

If early humans did possess at least a latent capacity for hibernation themselves, the severe conditions experienced in northern Europe during the Ice Age-marked Pleistocene Epoch could have helped trigger the activation of human hibernation.

We know that bears hibernate but now scientists suspect that Neanderthals also hibernated and that’s amazing! (Raymond / Adobe Stock)

Bears And Humans Sleeping Together Through Winter?

The imaginative theory posited by Arguaga and Bartsiokas is too new to be controversial. But doubts are inevitable. While scientists have recovered sequences of Neanderthal DNA from fossilized bones, and have had some success decoding their genomes, the information obtainable from ancient remains is restricted. Without samples of fresh DNA that could be used to clone new flesh-and-blood Neanderthals, there is no way to prove beyond a shadow of a doubt what kind of physiological abilities they did or didn’t possess. Analyzing 430,000-year-old fossilized bones can produce intriguing results, but not decisive conclusions.

“It is a very interesting argument and it will certainly stimulate debate,” forensic anthropologist Patrick Randolph-Quinney of Northumbria University in Newcastle, England told the Guardian when asked to comment on the article published by Arguaga and Bartsiokas. Randolph-Quinney added “However, there are other explanations for the variations seen in the bones found in Sima, and these have to be addressed fully before we can come to any realistic conclusions. That has not been done yet, I believe.”

In support of their hypothesis, Arguaga and Bartsiokas offer one more bit of intriguing information. They reveal that among the vast collection of human remains discovered at Sima de los Huesos, excavators also dug up the fossilized remains of an ancient bear, which in fact showed signs of bone damage consistent with hibernation. If we know for sure that bears where hibernating in this region, Arguaga and Bartsiokas reasonably ask: Isn’t it reasonable to conclude that early humans hibernated since their remains show signs consistent with that assertion?

Top image: According to the latest research, just published, human hibernation among Neanderthals is a likely theory. Source: Gorodenkoff / Adobe Stock

By Nathan Falde