Human Adaptation and the Prospect of Hibernation
수정일 2017년 12월 24일 일요일
등록일 2018년 12월 31일 월요일

New studies indicate that human beings might find innovative ways to adapt to cold temperatures in the future, perhaps even hibernating on spaceflight expeditions. The research focuses on TRPM8, which is a protein that regulates the mammalian perception of cold temperature, and those mammals that don't hibernate have already proven to be more sensitive to such temperatures than those that do hibernate. NPR also reports that a new discovery on the Bering Land Bridge and its surrounding environment give clues as to how else humans might survive climate change.

Owen Mason, a Ph.D. archaeological research associate for GeoArch Alaska and professor at the University of Colorado in Boulder, explains that the Bering Land Bridge was where woolly mammoths resided some 20,000 years ago. Mason highlighted finds onsite that make the point. "Right there, that's a whale shoulder blade," which is a bone comparable in size to a German Shepherd. In addition to the bones found there, closer inspection also reveals a trove of other artifacts, too. "Right here, that's an ulu knife," Mason said about what amounts to a smooth, flat, stone contrivance. "It's a specialized knife for cutting animal flesh. It's about 300 years old."

All the objects found required significant digging to unearth after a millennium of preservation in frozen soil in the Alaskan tundra. Mason elucidated that, under the grass, "there are at least 50 or 60 houses, maybe even 70, but that's just on this ridge alone. His team spent and is likely still spending considerable amounts of time digging up old, log cabins from the previous millennium. "The level of work that went into making that house — it's just amazing," according to Claire Alix, a University of Pantheon-Sorbonne archaeologist and professor at the University of Alaska Fairbanks.

Arguably the most pertinent find to human adaptation at the site, though, is what Mason and his team call a bola. It's a set of heavy weights on the ends of thread, according to him. It's considered to have been the optimal way to hunt birds at the time. "Trapping the birds as they fly seems like a very efficient means of hunting," Mason remarked. The bola did, however, serve as a means for human families to insert bird meat into their meals more often, which was especially critical at the time in light of climate change wiping out food sources.

"The device just seems to appear right around this time of climate change," Mason added. This is a necessary yet cultural means of coping with the extreme conditions. It was a behavioral necessity for the sake of human beings surviving in the area at the time. At around the same time, archaeologists speculate based on actual artifacts discovered onsite that these same early humans invented so-called wound pins. These are innovative tools used to nail an open injury together and thereby plug the wound. "You're sealing the wounded seal so that the blood is retained rather than lost as the animal is carried back to camp. That gives you something valuable in terms of nutrients."

Based on these early developments, early technology is one of the first ways humans coped with climate change despite late technology being greatly responsible for the current global warming crisis. Bill Gates advocates using technology to cope with climate change yet again. "We need to adapt to the climate change that is already affecting the planet, and develop new tools that will keep the problem from getting worse," Gates wrote on his blog Tuesday. "Innovation is key to doing both."

Experts are now saying in a study published this week that people may very well be able to adapt to lower temperatures in the future and tolerate them more easily, and they submit that the key to doing so can be found mammalian brains. Beyond that, they suggest that it may be a presently dormant ability that could be activated in human cells, which would facilitate the hibernation that other mammals already experience to cope with such temperatures. One gene that draws their attention in this regard is TRMP8, which controls a small brain region that controls the human body's response to the cold.

The study was conducted by scientists at Yale University who found hibernating animals like certain rodents in particular to hold answers. These rodents adapted over time by forming cold-sensing neurons in the brain that are less sensitive to temperatures under 20ºC (68ºF). TRMP8 is an adapted DNA strand that allows the body temperature to drop for prolonged periods without allowing the conditions to conjure stressors within the rodents, and this causes them to hibernate rather than perceive the full brunt of the cold. The Yale team, including Drs. Sviatoslav Bagriantsev and Elena Gracheva, observed this in the Syrian hamster as well as the ground squirrel.

"Future research will make it possible to confer cold tolerance to human cells with potential implications for medicine," co-authors Bagriantsev and Gracheva say. "Understanding the hibernation phenomenon, in general, will pave the way to inducing hibernation in humans, which seems necessary for long-term space flight." This, therefore, extends its implications beyond what humans can do to cope with terrestrial temperatures and conditions and may actually facilitate more challenging space expeditions, which is why the team's research suggests that the next milestone along this line of research is to genetically alter rodents "to make a non-hibernating species of mouse cold-tolerant by substituting the mouse TRMP8 gene with the squirrel" version.

Cedric Dent 기자
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