If New Englanders thought this
winter was unbearably cold, you clearly haven’t spent any time in Siberia
during the winter. Siberian winters can reach lows of -25°C (-13°F) and when comparing that to Amherst, MA temperatures of 5°F
and 15°F,
it would seem like we live in Florida compared to Siberian natives! It’s
shocking to think that 0.5% of the world’s population lives in such cold
conditions, but studies have shown that natural selection on the human genome may
play a key role in helping indigenous Siberian people to adapt to the frigid
north.
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A recent study
performed by Alexia Cardona, member of Toomas Kivisild’s genetic group at the
University of Cambridge, and colleagues observed 10 Siberian groups that made
up much of the native population and analyzed DNA samples in order to seek out
genes that evolution favored to help humans adapt to survive and reproduce in
cold climates. The DNA analysis proved successful because three genes;
UCP1, ENPP7 & PRKG1 were naturally
selected within various Siberian groups. The gene
UCP1 was selected for more in southern Siberian groups, and helps the
body’s fat directly produce heat rather than producing chemical energy for
muscle and brain function. The other two gene variants positively selected,
ENPP7, which functions in the metabolism
of fats in meat and dairy, were found selected for in most of the Siberian
region. The other gene,
PRKG1, was
greatly selected for in northeastern and central Siberian regions, and is
concerned with shivering and the constriction of blood vessels in order to
prevent heat loss. Alexia Cardona notes that these results, “
show how, over the more than 25,000 years that modern humans have lived in Siberia, various people have adapted to the region’s cold weather and meaty food sources through selection on multiple genes that control several biological mechanisms.” This new study really sheds to light how humans are constantly evolving and adapting in order to survive and reproduce and how natural selection is the key to all basic biological life. In this case, native Siberians would be unable to survive and reproduce in such cold conditions if it weren't for natural selection favoring these specific genes. Therefore, without natural selection favoring these types of genes, Siberia would not be the same as it is today and people would be unable to survive there.
So now begs the question, if Siberian natives have naturally selected genes to help them adapt to colder climates, do other people in cold
climates like Russians in the winter, or even people here in New England, share
those same naturally selected genes or are we all stuck bundling up, shivering,
and dreaming of the summer sun?
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Posted by Gabrielle Wertheim (3)
Considering that this has caused a difference in physiology simply based on where these people live, do you think that there may be other stronger physical changes in humans in the next one to two thousand years? What about in the next five thousand years?
ReplyDelete-Ashley Sterpka (1)
I definitely believe that natural selection will continue to evolve stronger physical changes in humans in the next however many thousands of years, especially with these new discoveries being made, like in Siberia.
DeleteGabrielle Wertheim (3)
I think that basically people developed extra characteristics to better suit their environments, the golden rule of Darwinism: adaptation. Different people living in different areas will develop different adaptations to assist in making living easier.
ReplyDeleteNick Mulone (3)
I completely agree, its a perfect example of Darwinism: adaption. I'm pretty certain that if these native Siberian people didn't have these types of genes to help them survive such temperatures, they wouldn't be living there! This is definitely a "survival of the fittest" type of situation because the natives that didn't have these cold climate genes most likely didn't survive to reproduce and only the natives with these positively selected genes survived to reproduce. Its fascinating to see natural selection and adaptation firsthand like this.
DeleteIt's hard to imagine that a species like ours where survival has more to do with socioeconomic status than environmental adaptations can still be undergoing natural selection. I wonder how gene expressions in an African person would compare with a Siberian person in the distant future.
ReplyDeletePosted by Poya Jafari (2)
I wonder how long it took for those three genes to be singled out as they are today. It's an interesting thought, but I doubt that over the 400 years since Europeans settled in New England their genes have changed much. It's more possible that Native Americans share similar genetic traits. I'd be interested to look into that.
ReplyDeleteLindsey Dugas (1)
Interestingly enough, the article actually makes a point that it is believed that Siberians are the original population of Native Americans and that there is a possibility that Native Americans also posses these cold adapted genes. Unfortunately, its not quite known how long ago these genes were singled out, but it is believed that earlier humans, including Neanderthals, which occupied cold climate areas may have already had these genes in order to help them adapt, however, that has not been exactly discovered and confirmed yet.
DeleteI was thinking the same thing as I read the conclusion of the post. I'm sure if Siberians have these adaptations that they would likely also be visible in Native Americans, especially those in the colder regions. It would also be interesting to see if various indigenous people from colder regions originated from a specific sub-group, or if they adapted these traits independently.
DeleteMichael Ball (1)