All animals have physical features that help them live in their environments, of course. A fish’s body is perfectly suited to life underwater, just as our human bodies are adapted for surviving on the land. What is a bit more nuanced and intriguing, though, is when we find specific adaptations to local landscapes, ones that are so much a part of us that they show up in our genes—and what this means for our felt connections to our homelands.
One such case was discovered in the summer of 2010 when genomic scientists found DNA mutations in the genes of Tibetans that allowed them to easily acclimatize to heights.
Could the rest of us have similar deeply ingrained connections to our home grounds—forests, oceans and tundra?
Genetic makeup vs. athletic training
In a study conducted by evolutionary biologists at the University of California, Berkeley, a comparison of the genomes of 50 Tibetans and 40 Han Chinese showed that ethnic Tibetans split off from the Han less than 3,000 years ago and since then have rapidly evolved a unique ability to thrive at high altitudes and low oxygen levels. The researchers identified 30 genes with DNA mutations that were more prevalent in Tibetans (and presumably Nepali Sherpas) than in the Han Chinese. One mutation in particular spread from fewer than 10 percent of the Han Chinese to nearly 90 percent of all Tibetans, the fastest genetic change ever observed in humans. That widespread mutation is near the “super athlete” gene EPAS1, a gene nicknamed for its link to improved athletic performance.
When a person born and reared at low altitude ascends the high mountains, his or her functional traits change over time as acclimatization occurs. For example, when you or I journey to the Himalayas, our bodies compensate for the thinner oxygen levels by producing more hemoglobin, increasing the blood’s ability to transport oxygen. But more hemoglobin also thickens your blood, making it harder for the heart to pump, which sometimes leads to acute altitude sickness. Tibetans produce less hemoglobin in their blood yet function well at altitude. So while a person born and reared at low altitude can ascend the high mountains and allow his or her functional traits to change over time as acclimatization occurs, such a person may never acquire a close physiological resemblance to people born and reared at high altitude.
For these Tibetans, then, body and place are physically connected.
Inner landscapes
It seems to me, then, that mountains are in Tibetans. And although we don’t yet have the science to prove it, I would guess there are landscapes in other peoples, too. Indigenous cultures around the world often speak of their innate connections to their native grounds. Someday, after a long enough time has passed, we may find that here in the United States there are oceans in Easterners, prairies in Midwesterners and open spaces in Westerners.
Others of us instinctively know that a certain landscape is “in our blood,” so to speak—even if we, ourselves, weren’t born to it. Someone who has lived all of his life in the interior of the continent may know that he is an “ocean person,” or someone from the South may feel that she is more comfortable in Northern climes. Some native flatlanders might find they need to live in sight of a mountain. Will we discover someday, then, that that is the result of a strange and rare fleck on a speck of a gene from a distant relative, or will the landscapes that call us always be a matter of the heart?
Is there a certain landscape that’s in your blood? Is it the one you were born to, or the one that never fails to inspire you?
Here’s to finding your true places and natural habitats,
Candy
Nice piece. Thanks very much, Candice.
Yes, I have the northern forest band from coast to coast of the US in my blood!
Fascinating.
great article!
Very nice article . This may provide useful help in in depth studies in the field of high altitude adaptation physiology.
I find your articles always refreshing & insightful. Thanks.
This is absolutely fascinating information, as is the question it engenders. As a born and bred Midwesterner, I have always had a deep feeling for mountains and have had many of my most fulfilling and soul satisfying experiences among them; this is despite a degree of acrophobia that precludes any actual mountain climbing, as well as a couple of bouts of mild altitude sickness.This has long led me to wonder if my Norwegian and Austrian genes are somehow responsible for my preferred terrain.
The change from 10% of a population having a genetic adaption to suit high altitude living to 90% must have been the result of natural selection. The physical advantages the gene conferred must have enabled those with it to survive better and reproduce more successfully at high altitudes than those without it. Assuming 10% of Han always carried the high-altitude geneotype, they and their progeny with the same genetic inheritance so out performed those Han who did not have the gene (even if they could physically adapt to high-altitude living) that over 100 generations, the genetic trait had become almost universal among Tibetans.
It will be interesting to see whether different selection criteria in modern times will favour a different set of genes. Those genes favouring intelligence, inventiveness and adaptability may prove to be more valuable to the survival of future generations than mere physical endurance which favoured their ancestors.
I would back the Han rather than Tibetans to prosper over the next 100 generations!
Interesting and thought provoking. Am I genetically predisposed for mountains, classical music from quality orchestras, cats and travel? Or is it just wanderlust!!
Thank you so much for this post Candy.
I observed something different last year and since you mentioned Sherpas, I thought I’d just mention it here. I was in the Khumbu region in Nepal last year same time and it so happened that my trekking and climbing schedule coincided with that of another Sherpa who was US based, and had been there for about five years. So we just happened to walk a few stretches together.
At about 4000 m or so, my Sherpa friend started feeling the first effects of AMS and just ignored them more out of ego than anything else i.e. “How can a Sherpa get mountain sickness” – you see, it is “sacrilegious”. Continued climbing and at 4200 m, just couldn’t manage anymore and had to head back while yours truly, this plains-born and bred man continued. So while I agree with the genetic mutations bit, possibly the immediate environment also has a reversal effect on such acclimatizations. And now this might become the subject for someones PhD (if it hasn’t already)!
Very nice comment. You are right there must be an in depth research on this issue. We have to see genetic mutation as well as current habits and environment.
I so enjoy your site and hope to travel with you one day. Like Leslie, I love being in nature. I have a small farm in a rural setting. Of course we being encroached upon, mining, road expansion, development. I especially love the Swampy, Mucky places there is so much life there. I definitely do not have a city gene.
I believe the same is true of Andean native people.
While I love Manhattan’s cityscape, my being responds best to nature. I love seashores, lakes, ponds and rivers; mountains, woods and farmland; snowscapes anywhere; rolling hills, intriguing mountains, as well as flat lands against the backdrop of any type of higher ground. I love the aromas of nature, the sounds of water, and the beauty of almost anything in a natural, undisturbed settings. The one gene I’m pretty sure I don’t have is the one for climbing heights!