I took an anthropology class this past semester, and it we learned about "Human Variation" and the "rules" various people who have studied this sort of thing have come up with.
Bergman's Rule states that more slender people tend to populate warmer climates, while more robust people tend to populate cooler climates. And as an example, take a look at the Inuit who tend to be heaver-set.
Allen's Rule says that protruding parts (limbs) tend to be shorter in cooler climates than warm climates. Again ... the Inuit tend to have shorter arms and legs, and bigger torsos.
Quoting from my text:
"The rationale behind these theories is that the long-limbed, lean body type often found in equatorial regions provides more surface area in relation to body mass and thus facilitates the dissipation of body heat. In contrast, the shorter-limbed body type found among residents of cold regions promotes retention of body heat because the surface area relative to body mass is less."
Through some experimentation they also discovered that facial structure may be affected by environment - it appears that those who live in cold climates have plumber faces and noses with very narrow or small nostrils. The theory is that the small nasal openings is a way of protecting the lungs from cold air, and the faces have more fat which keeps them warmer.
Just a theory here ... having lived in a cold climate all my life ... and having spent a great deal of time throughout my life outside in the cold, perhaps I've got the body type and facial adaptations (see "chubby cheeks" in photos :)) to be able to handle it. I can cycle (or ski or whatever) for hours in bitterly cold temperatures with no adverse effects, and yet it seems to affect others. In fact, I feel the cold in my fingers and toes ... and my ears if they are adequately covered ... but my face simply does not feel the cold.
cedo
12-21-05, 08:40 AM
I have the "equatorial" body type. Add to that a low body fat, and I have a hard time maintaining core body temperature in extreme cold. Nonetheless, I love winter commuting where increased physical activity keeps me quite toasty. Not a day goes by, riding the elevator up in the morning, where people comment on how "brisk" it outside (singe digits) and I often remark that my problem is keeping cool!
joeprim
12-21-05, 09:00 AM
I think this is also true of deer with the addition od ear size. The furthur south you go the larger their ears to keep them cool along with the charicteristics you mention for people.
Joe
DCCommuter
12-21-05, 09:45 AM
I've also read that the Innuit have different blood vessel routing, that more of their blood is in the body core to conserve the heat.
I've noticed that my body adjusts to the cold and kicks up the thermostat when I'm exposed to the cold. I love being out in the cold all day, and then coming inside and feeling toasty warm at room temperature.
Bekologist
12-21-05, 10:36 AM
most mountaineers and high altitude climbers are tall, lean and lanky...but that's probably just advantageous to the sport, versus a biological precedence for mountaineering....
you can condition yourself to adapt to cold extremes better than adapting to heat, and I always choose vacations to cooler climes if possible due to this. I grew up in a very cold environment, too, so perhaps I have 'adapted' more than my pure biological disposition. my BMI is pretty low, but I don't shy from the cold.
Native American wisdom has you running around in the snow barefoot to toughen up your ability to handle cold. I think going outside to stand in the snow, barefoot, on your porch, while you sip your morning beverage, and stand there untill you can't stand it any longer, does wonders for your cold tolerances. At least localized.
Generally speaking, long distance swimmers are fatties for warmth, but not lap length swimmers, and fat lugers have an advantage over skinny lugers, but that's just gravity.
But hey, anything that justifies that extra weight....
rich007
12-21-05, 03:39 PM
most mountaineers and high altitude climbers are tall, lean and lanky...but that's probably just advantageous to the sport, versus a biological precedence for mountaineering....
Westerner mountaineers yes, but if you spend some time in the Himalayas, around local Sherpas, who are basically Tibetans, you'll see that they are smaller and 'chubbier', closer in appearance to the Inuits of the North.
One of my rather stranger encounters when climbing in Nepal and Tibet was to see young Tibetans walking in flip-flops when outside temperature was close to, or even below, 32 F... My climbing buddy from New Zealand who lives in Nepal explained to me that Tibetans are physiologically better adapted to altitude (and cold) than any other 'race'. Their blood flow to extremities doesn't get reduced, or cut off, to preserve core body heat, so when you shake their hands, or even touch their bare feet in a camp, after all day walk in around freezing temps, they are warm. Non-Tibetans hands are cold, or even slightly frost-bitten after similar exposure. When faced with extreme cold, the circulation slows down, but never cuts off, unlike ours.
Plus, they naturally hyperventilate when going higher up to prevent AMS (altitude mountain sickness) and I'm not talking about controlled hyperventilation during heavy exercise (such as climing, biking at altitude), everyone can do it. What I'm talking about is a hyperventilation during rest and sleep, they breathe more rapidly and deeply, unlike us, lowlanders, who usually have more interrupted and shallow breathing. Because of that, IIRC, their oxygen saturation in blood at altitude is always higher when compared to lowlanders.
The continued circulation to extremities and higher oxygen saturation is a reason why they are able to work harder and suffer less cold injuries (esp. frostbite) at extreme altitude (above 5,500 meters)... Their abilities high up on Himalayan mountains are superhuman, and only in recent, 10 or so, years they have been getting 'some' credit for it...
All of the above adaptions are not possible to achieve through training, or conditioned exposure to cold, Tibetans acquired it through genetic mutations of living at high altitude for generations.
Satyr
12-29-05, 08:38 AM
I took an anthropology class this past semester, and it we learned about "Human Variation" and the "rules" various people who have studied this sort of thing have come up with.
Bergman's Rule states that more slender people tend to populate warmer climates, while more robust people tend to populate cooler climates. And as an example, take a look at the Inuit who tend to be heaver-set.
The Inuit also subsist primarily on fatty foods (and consequently also have high rates of colon cancer/osteoporosis) which could explain aspects of the heavy-setness. This of course doesn't contradict any cold-weather adaptions.
balto charlie
12-29-05, 11:12 AM
My take on it is eons of evolution and not because you 'happen to live there". Skinny eskimos died because they couldn't withstand the cold thus they did not reproduce, Navaho Indians tend to be large with slow metabolism and the theory here is feast/starvation lifestyles. Some years food was plentiful, other years it was scarce. Those with slower metabolism survived and those with higher metabolism died out during famines. Again the gene pool is altered. My personnal info: Hispanic/Irish background, born in LA but spent 30 years in Mid Atlantic region,, average build, 6 ft. tall, dislike the heat, thrive in cold, big nostrils(tho' I can't really measure them) I think one can adapt to their climates to some degree but I doubt it would change their overall appearance. All this said: I really dont' know the answer but it's fun to speculate
willtsmith_nwi
12-29-05, 05:21 PM
This is evolutionary stuff. It really doesn't apply to you personally.
It means that natural selection stochastically (statistically) favored certain body types in certain areas. Those body types were more prolific hence they dominate the gene pool in a given region. But you will notice that within those populations there is still genetic variation that pops up through recessive traits. It's the beauty of evolution that maintains "losing" designs inside the DNA of "winners". Suddenly the climate might change the rules of the game and all the "winners" will die off.
In North America, this means even less because the vast majority our population is imported AND mixed with other races (Country ancestory no longer forms a basis for race, only contintental anscestory.
I've found that trying to racially stereotype environmental capability to a race is a pretty tricky business. About the best thing you can say is that black folk resist sun cancer better than white folk.
The human body itself has a tremendous capability to adapt. And you do not need to be inuit to get fat enough to resist the cold.
Just measure you tolerance for 50 degree weather in the fall. You'll be dawning pants and fleeces. When 50 degrees comes in spring you're wearing shorts, sandals and t-shirts. The body adapts.
Just a theory here ... having lived in a cold climate all my life ... and having spent a great deal of time throughout my life outside in the cold, perhaps I've got the body type and facial adaptations (see "chubby cheeks" in photos :)) to be able to handle it. I can cycle (or ski or whatever) for hours in bitterly cold temperatures with no adverse effects, and yet it seems to affect others. In fact, I feel the cold in my fingers and toes ... and my ears if they are adequately covered ... but my face simply does not feel the cold.
GGDub
12-30-05, 09:53 AM
I think the body can adapt to cold quite quickly. At the beginning of winter, I always need to cover my face when riding or when working in the field by January, I can ride in -20c without covering my face.
A few years ago, I was doing a geotechnical investigation on Baffin Island in february. My drilling crew was predominantly inuit. It was -30c out (the high for the day) with a good wind and these guys had there coveralls open and weren't wearing toques (winter hats). They were skinny guys as well so the body fat theory didn't hold.
What's even more amazing was that the year before one of the worker's uncle had fallen through the ice while out hunting with a buddy. His friend couldn't safely get to him so he went back for help. This guy apparently survived 2+ hours in the water before he was rescued and came out with some hypothermia and mild frostbite!
ItsJustMe
12-30-05, 12:34 PM
I heard in a bio class in college that people from races that developed in warm areas and cold areas have different responses in their extremeties when it gets cold. Those in warm areas shut down their extremity circulation to conserve heat. Those in cold areas also shut down to some extent, but not as much, to avoid frostbite, and (I can't remember exactly) maybe increase circulation if they begin to approache frostbite.
timmhaan
12-30-05, 12:45 PM
... but my face simply does not feel the cold.
yep - this is where we are different. even in relatively warm upper 20's and low 30's my mouth area gets numb from the wind. sometimes it's hard to talk even because i just can't move my lips enough. i have very little fat on my face, actually my whole family is like this.
mimis
12-30-05, 02:11 PM
My body type is of the heavy torso and indeed i can't tolerate the heat,i sweat too much (how embarassing in social terms..). Winter cycling is my favourite and my best performance season of the year! Keep givin' us food for thought
Black Bud
01-02-06, 05:02 AM
I find that I get hot cycling all year long! Yes, describing me as a "Clydesdale" would not be inaccurate... I am definetly plump! And, my face does stay warm...the reason I use a balaclava is to warm up my breath...so I don't end up short of breath and cough my way to work!
I get cold only...after I stop! ;)
My problem: Hands and feet...both due to the lesser circulation and simply the exposure to the wind...they get hit the hardest that way. So...extra socks and thicker gloves are de rigure!