Seems like an Eskimo type build would be a better body for cold climes re heat retention. Why are European Nordic types so (relatively) tall?
For one thing, the climate in the Nordic countries isn’t anywhere near as cold as Siberia (where the Inuit are originally from). The Inuit also lived in the Arctic region much longer than the ancestors of the current Germanic peoples in the Nordic countries. It would probably make more sense to compare the Inuit with the Sami, who aren’t nearly as tall as their Scandinavian neighbors, but we don’t really know how long they lived in the Artic regions of Europe.
BTW, the “Nordic” girls in that photo don’t look very tall. It’s hard to tell without a reference, but the don’t look particularly long limbed.
Google wasn’t delivering long limbed Scandinavian goodness. This was my other choice of Google Image Swedish person photos. Be glad you got the girls.
The OP is basing the question on a big assumption. There’s a good description of historical changes in height of populations here: http://news.bbc.co.uk/2/hi/health/3625031.stm
And I think Mr. Mace has hit on the main point here. It isn’t being short that is an adaptation to the cold, it’s the surface area:body ratio, usually measured by limb to trunk ratios. A tall person will actually be be better adapted to the cold than a short person, provided both have the same build.
The principle at work here is that the body loses heat by the skin and it generates heat via the muscles. A sphere gives the minimum amount of skin to contain a given mass of muscle so cold adpated people tend towards ‘spherical’ with short rounded limbs, bodies and heads.
What all that means in practice is that a person can be tall and actually better cold adapated than a short person provided that the limbs and body maintain the same proportions. The extra muscle generates extra heat, but because the skin area is multiplying as a square (area) function while the muscle is multiplying as a cube (volume) function the increase in size actually generates more heat relative to heat loss the taller a person gets. That’s why animals in cold enviuronments tend to be larger than comparable animals elsewhere, and why so few small animals inhabit cold regions.
Which means that we should actually expect cold adapted people to be tall. That doesn’t happen in practice because diets haven’t allowed people to simply scale up. There was a maximum body mass people could sustain, and the evolutionary choice was between tall and thin or short and stocky. Cold climate people went down the short and stocky route.
But that doesn’t mean that with modern diets these people can’t be tall. All it means is that we shouldn’t expect them to be long limbed. And as John points out, those people in your photo don’t look particularly long limbed.
Those guys are still not particularly long limbed. To give some idea what I mean, try to visulaise the arm length as proportion of shoulder width. Those guys probably have an arm length of about 1.5 shoulder widths. In contrast look at these guys where the arm length is probably closer to two shoulder widths. That’s long-limbed.
I personally have never associated Nordics with long-limbedness. All the long-limbed female models for example seem to hail from France or Southern or Eastern Europe.
You’re right, they’re not long limbed, nor are they exceptionally tall, they’re just a bunch of lutefisk chewing, clog wearing, cheese eating white people. What was I thinking?
My point is that you’re right, they are not all that tall. I was apparently over emphasizing their tallness in my OP.
Those people may all be over 6’ for all that I can judge from those photos. That shouldn’t come as any surprise on modern diets and healthcare because there is nothing in frigid climates that specifically selects against such height. However what remains constant is the limb ratios. Those people all appear to be the typical short-limbed cold-temperate types. They may be somewhat longer limbed than the typical Eskimo but it’s hard to judge. Certainly they aren’t radically longer limbed.
As I said above, all things being equal the taller the person the better they will handle the cold. Provided she had sufficient food a 7 foot Eskimo would be far better able to handle the cold than a 5 foot Eskimo. It simply isn’t shortness that will be associated with cold climates, it’s stockiness. Just as it isn’t height that is associated with heat, it’s thinness. And just as we expect there to be short-yet-thin tropical pygmies so we should expect there to be tall-yet-stocky frigid ‘giants’.
My point being that you made a flawed assumption in your opening post. An Eskimo body type and a tall body type are not mutually exclusive. That’s because the Eksimo body type is defined by proportions, not overall length. It’s perfectly possible to be 6’6" and still have a classic Eskimo body type.
So it’s perfectly possible that Nordic types do have Eskimo body types despite being tall. It’s not an either/or decision.
The OP clearly never met by grandmother. “Tall” my foot.
Whoa - these are my people (except that I’m strawberry blond, blue-eyed, and Italian). I’d never thought before about ethnic bases for limb proportions - I just noticed that some people’s arms extend about to their waist, while mine go down past mid-thigh. Reddish hair, long arms - can you say orangutan?
In addition to the 1.5-to-2.0 times shoulder width figure Blake cited, I’d also heard that arm span usually equals height. For me, I’m 5’11" but my arm span is >6’5". Oh well, sorry for the divert.
First off, the “Nordic” people we see havn’t been living in the cold long enough to get these traits.
Secondly, we expect Nordic people to be tall and Nordic looking, so when we see a picture of a fat blonde guy we dismiss it as not an example of the Nordic type. Likewise, we expect protrayals of Eskimos to be short and fat, and we get what we want.
My poorly constructed OP has been succiently answered by the biology mavens, so let’s just let it die. There’s nothing more to say on the subject. I made a mistake. Nordics aren’t Watusi’s. I’m sorry. Nothing more to see. Let’s let it float to the bottom peacefully.
And how do Samoans fit into this picture: tall, stout, and tropical?
Samoa has only been occupied for a bit over 2,500 years. That’s only 1000 generations and simply not long enough for any serious natural selection to take place. Maybe if 50% or more of people had died from heat intolernce it would be posible over that t ime frame, but realistically that just won’t happen. Instead the evolutionary pressure is far more subtle and tends to favour certain body types when other stressors are applied.
Imagine we started with 1000 Samoans with a normal height distribution and that a slightly thinner frame gave even a 1% increased chance of survival. That means that the “tall” half of the population will have 1% more kids than the short half. In the second generation we’d see 55 people slightly taller than the original average, in the 3rd generation we’d see 60, then 66, 72, 80 etc. After a thousand generations the entire population still wouldn’t have exceeded the original poulation average.
In short, people simply breed too slowly for selection to take place over such short timescales unless the selection pressure is catastrophic. And there’s no plausible mechanism for heat stress causing a catastrophic loss of life. Then we can add to that any selection pressures against a lean body form and you can see that the chance sof seeing any noticable change in that time period are about nil.
The Samoans still retain the basic traits of the ancestral popualtion, and that ancestral population appears to have been SE Asian with some Melanesian Australoid thrown into the mix.
[nitpick]
Not Eskimo…Inuit is the correct term.
“Eskimo” is actually a slang word meaning “Eater of raw meat” and is generally considered offensive by the Inuit.
[/nitpick]
Not only that, but it’s not only climate that causes variation in body mass. There are plenty of other selective pressures at work as well. I would speculate that perhaps the frequency of food shortages in Pacific Islands is greater than in many parts of the world (since the islands are small, the ecosystem is relatively small and more vulnerable as well), which would likely make efficient fat storage a necessity. I don’t know much about anthropology, but I’ve read that heavily agricultural societies tend to be leaner than hunter-gatherer societies in general, and at least in most of Polynesia agriculture accounted for only a small portion of the traditional diet.
In any case, Samoa being an oceanic island, it is generally not going to get that all that hot - it won’t be anything like a continental tropical area. On top of this, if people spent a lot of time at sea fishing (especially in rainy conditions or at night), or did a lot of diving, the ability to retain heat could have been beneficial.