Are we more adapted to certain fruits?

[TylerDurden]

My reason for going on about the human ability to thrive is based on my own experience. Due to a ravaging of my health, my glandular system became increasingly fouled up over the years so that by the age of 17, I would often start to sweat heavily in temperatures above 10 degrees Celsius, and temperatures above 30 degrees Celsius were an absolute misery for me. So, I far preferred temperatures at 0 degrees Celsius to 5 degrees Celsius not because they felt pleasant but because I loved not having to sweat at such times. Then, once I went rawpalaeo, my body stopped being so hypersensitive to heat as before. My circulation also improved a lot and I slowly found myself preferring colder temperatures for other reasons. Now, granted that such symptoms probably arose from poor health and then via  a new diet rather than any genetic influence, but who knows? I would like to think that my experience is down to my having specific Neanderthal DNA  in my ancestry that protects me from the cold better than other humans. Be that as it may, if I can develop some cold-tolerance/cold-adaptation via non-genetic means, then it certainly seems likely that with a little evolution, some hominid ancestors also managed to adapt themselves to the cold without needing to have fur on their skins.

[JeuneKoq]

Even arctic foxes have other adaptations other than fur. They have a generally rounded body shape to minimize the escape of body heat, and, most importantly, they have to eat vast amounts of food in the autumn so as to gain c.50% extra bodyweight and so survive the winter. Polar bears practise an odd form of "walking hibernation" in order to deal with the fact that winter involves a reduction in the amount of prey, and so on and on. My point was that fur is merely one type of adaptation to cold and many other(non-technological) methods can have allowed ancient  hominids to adapt to the cold without ever needing to grow fur or wear artificial furs.

Yes, land mammals from Arctic climes do have numerous ways to fight the cold such as more brown fat, higher metabolism, body shape, food storage in fat tissues, etc... And all of these work remarkably well when associated with a heat conserving mechanism such as fur, or "reinforced" feathers.

Without one of these two heat trapping mechanism, the mammal will just be wasting too much energy trying to keep its whole body at a viable temperature.

Humans, even Central and Est-Asians, are straight-up, bipedal animals, who are most exposed to the wind comparatively and in proportion to quadrupedal land mammals. Cold-adapted humans would have to be a lot smaller and/or stockier than present day Est-Asians to at least survive moderate temperatures. The Fuegans are (or were) on the verge of reaching that state, even though they must still use some basic artificial heat generating or conserving mechanisms to survive the above-zero temperatures.

An efficient heat trapping mechanism such as thick grease layer, fur or feathers is indispensable to survive long periods of more extreme cold.

Incorrect. I have already shown a myriad ways in which humans (or other animals) can easily survive in arctic climates without needing to wear  furs or  use any other technological aids such as fire.

No, you have not. Nothing realistic, at least.

Also, may I remind you that we are not talking about short-term survival to sub-zero cold, which human can accomplish by paying a gradually increasing energetic cost, but long-term survival. A whole winter.

You are falsely assuming that Germanic people originally evolved in a cold environment. [...] I recall that Caucasoids have been claimed to have originated in temperate forests, but, strictly speaking, no one is sure of their origins at all.

So how can you assume yourself that my assumptions of Germanic people having originally evolved in a cold environment are false, when you're both suggesting that they originate from areas that regularly witness sub-zero temperatures in winter, and that nobody really knows anyways?

Obviously wrong, when other methods such as feathers are at least as good.

True. I even said so last post:

"All miniature mammals with fur or feathers, which work in a very similar way. Aren't winter covers and snow vests regularly stuffed with plumes?"

No, yours is not a valid argument at all. You make a vague supposition that fire (for warmth) was invented c.500,000 years ago. In actual fact, other than kooks like Wrangham(Wrongham), the date for the invention of fire for warmth is set at around c.400,000 years ago, with the use of fire for cooking  occurring  c.250,000 to 300,000 years ago.So, you see, it makes no sense to assume that something happened much earlier without any evidence , especially when the  contrary evidence is solid and shows that clothing  only got started being used from c.  83,000 to 170,000 years ago or so:-
http://www.smithsonianmag.com/smart-news/lice-evolution-tracks-the-invention-of-clothes-123034488/?no-ist

You see, the scientists did not simply assume that the use of animal hides had to mean clothing, they actually checked the evolution of head-lice and body-lice to see when they diverged from their former evolution to become adapted to humans. So, the notion of clothing being invented half a million years or more earlier, is clearly invalid.

Results from this study seem sound, although we can still find opposing arguments to the idea that hominids did not wear fur in the times of the Northern conquest, as the researchers also point out themselves:

-hominids regularly changed the fur they were wearing, which could make lice adaptation to clothes slower (not very likely).
-hominids left Africa later than thought.

I find it unthinkable the idea that hominids had invented flint stones some 1.7million years ago or earlier, but still could not cut the skin off of animals to protect themselves. I also cannot make sense of the suggestion that hominids could survive without an efficient mean of body-heat conservation, and rely almost exclusively on very energy-expensive internal heat generating mechanism. A Northern clime mammal such as the one pictured would not last one harsh winter.

Some of these animals clearly rely less on furs/feather and more on other practices such as huddling or reducing blood-flow to the extremities etc.etc.

How do you know to what extent an animal relies on its various cold protection mechanism?

[JeuneKoq]

Are even Native Americans adapted to potatoes and tomatoes, as they have not been there all that long? But my point is valid:- if adapting to slightly different foods is a big effort, then, logically, many other adaptations will also have happened prior to that food-adaptation occurring.

Personally I have no digestion problem with tomatoes, but the idea that you must look African to do well on food native to Africa is just wrong. Their generally longer limbs (what about Pygmys?) and dark skin is an adaptation to the warm, sunlit environment, not their diet.

From sources like these:-
http://en.wikipedia.org/wiki/Human_evolution#Early_evolution_of_primates

Found it:

"The genetic revolution in studies of human evolution started when Vincent Sarich and Allan Wilson measured the strength of immunological cross-reactions of blood serum albumin between pairs of creatures, including humans and African apes (chimpanzees and gorillas).[24] The strength of the reaction could be expressed numerically as an immunological distance, which was in turn proportional to the number of amino acid differences between homologous proteins in different species. By constructing a calibration curve of the ID of species' pairs with known divergence times in the fossil record, the data could be used as a molecular clock to estimate the times of divergence of pairs with poorer or unknown fossil records.

In their seminal 1967 paper in Science, Sarich and Wilson estimated the divergence time of humans and apes as four to five million years ago,[24] at a time when standard interpretations of the fossil record gave this divergence as at least 10 to as much as 30 million years. Subsequent fossil discoveries, notably "Lucy," and reinterpretation of older fossil materials, notably Ramapithecus, showed the younger estimates to be correct and validated the albumin method."

Your assumptions regarding the time of divergence of humans and apes seems to be out-dated.

The current interpretation is that hominids and aped diverged at the time of the rise of the Rift Valley in Est Africa some 8-9 million years ago, which makes sense if you consider the thought that hominids were quickly adapting to a drying-out environment, hence the bipedal position among other things.

[TylerDurden]

Your last post made 2 false assumptions. I was not stating at all that one had to develop other traits such as dark skin in order to be better able to adapt to consumption of african fruits. All I had said was that IF it really took such a very long time to adapt to eating african or non-african fruits  after switching to the relevant climate, then, obviously, other climatic adaptations, such as darker skin etc., would have in the meantime taken place. Merely a question of length of time, not a requirement of adapting to different foods.


2nd false assumption was that I was focused on the split between humans and apemen. I merely gave a vague  example, but my whole point was that this absurd notion re better adaptation to african fruits  did not really hold water if our remotest ancestors were not based wholly  in Africa for aeons. Turns out, one of our remotest ancestors, Dryopithecus lived all over the Old World, not just Africa.Homo Erectus has been found in many places outside Africa, right up to Java etc. etc.

[TylerDurden]

Yes, land mammals from Arctic climes do have numerous ways to fight the cold such as more brown fat, higher metabolism, body shape, food storage in fat tissues, etc... And all of these work remarkably well when associated with a heat conserving mechanism such as fur, or "reinforced" feathers.

You failed, of course, to address my point which was that the various arctic animals must use a multiple number of additional tactics to adapt to the cold, some of which (such as "huddling") have also been   practised by humans for aeons. Many cold-dwelling mammals, especially the very small ones, do not have more than a very  thin fur layer and cannot realistically maintain more than that, so need much more than just fur in order to survive. And it's not just feathers for birds, some mammals need blubber instead of fur. Plenty of other  species have a variety of  widely different cold-adaptations such as great white sharks which have the ability to retain heat in parts of their bodies circulatory systems, allowing them to survive in colder waters than most other shark species.

Without one of these two heat trapping mechanism, the mammal will just be wasting too much energy trying to keep its whole body at a viable temperature.

Incorrect. True hairless rats, for example, just need to compensate by adopting a much higher  body-temperature. Simple as that.

Humans, even Central and Est-Asians, are straight-up, bipedal animals, who are most exposed to the wind comparatively and in proportion to quadrupedal land mammals. Cold-adapted humans would have to be a lot smaller and/or stockier than present day Est-Asians to at least survive moderate temperatures. The Fuegans are (or were) on the verge of reaching that state, even though they must still use some basic artificial heat generating or conserving mechanisms to survive the above-zero temperatures.

No they did not have to use artificial heat-generating mechanisms in order to survive. They were already able to survive without those, it was merely a matter of comfort to use such extras. And your point  re temperatures is not exactly right. The annual average Fuegan temperature of 5.3 degrees Celsius mirrors that of the average annual temperature of the whole of Siberia! In other words, large parts of every  year were spent by the Yaghans in freezing, subzero temperatures. As regards the modern East Asians, their height has been increasing heavily in the last few decades solely due to a change in diet. In the palaeolithic past, before the Neolithic era, they were much smaller. And, anyway, one does not need to be as short as the Yaghans were in order to survive arctic climates. The Neanderthals were slightly taller than the Yaghans and did just fine for countless millenia  until early modern humans arrived and wiped them out.

An efficient heat trapping mechanism such as thick grease layer, fur or feathers is indispensable to survive long periods of more extreme cold.

Yet I have already shown that an increase in average body-temperature, among other minor  evolutionary gimmicks, such as shorter limbs in relation to the body etc. are all that is needed to survive in places of extreme cold. The Yaghans, for example, were usually naked, preferred to sleep in the open and their women liked to swim a lot in the (ant-)arctic waters. Hardly an example of  a people shivering and barely surviving. These people positively thrived in the cold due to one key fact - they had an average body-temperature 1 degree above usual. Bear also in mind that these Yaghans were merely Neolithic-era hunter-gatherers so are unlikely to have kept most of the evolutionary adaptations that hominids had in the palaeolithic era due to natural selection. In other words, a palaeolithic-era tribe subject to natural selection, without knowing about fire etc., would  undoubtedly have been even more able to survive in arctic climes than even the Yaghans, and the latter positively thrived in semi-antarctic climes, anyway.

Also, may I remind you that we are not talking about short-term survival to sub-zero cold, which human can accomplish by paying a gradually increasing energetic cost, but long-term survival. A whole winter.

Ah, it is very clear that you are not all that familiar with survival techniques, let alone the survivalist philosophy. You are approaching everything from the viewpoint of a modern human, stagnating in a settled culture, along with central heating etc. Obviously, modern humans, if they spend all their lives in  centrally-heated buildings, always have access to hot water etc., they are unlikely to suddenly thrive, if suddenly paradropped naked into Greenland. On the other hand, if their descendants were forced to live their  whole lives in subarctic climes with little assistance, one can be sure that they would begin to start developing  adaptations to the cold quite soon, and more permanent adaptations over many generations, even without the aid of technology.

More to the point,my father once told me of how when an acquaintance of his was caught by a blizzard in Norway, the guy built a snow-cave and sheltered therein. It seems snow is a very effective insulator/heat-retainer:-
http://www.motherearthnews.com/diy/snow-caves-and-winter-shelters-zmaz82ndzgoe.aspx

The obvious point is that there are multiple methods of adapting to the cold without needing  technology.

So how can you assume yourself that my assumptions of Germanic people having originally evolved in a cold environment are false, when you're both suggesting that they originate from areas that regularly witness sub-zero temperatures in winter, and that nobody really knows anyways?

You are slightly misrepresenting  me. I had said that I had heard of  a vague claim that Caucasians came from temperate forests , to which I clearly did not give credence to, and made it clear that no one actually really knows where exactly they came from.That said,like I said earlier, East Asians are so much better adapted to the cold than Caucasians, that, clearly, the notion that Caucasians developed as a result of living in a cold climate is extremely unlikely.

True. I even said so last post:

"All miniature mammals with fur or feathers, which work in a very similar way. Aren't winter covers and snow vests regularly stuffed with plumes?"

Pillows  stuffed with feathers etc. is a technological improvement not designed for survival per se, but for increased confort in our modern, decadent world. And I had already mentioned numerous ways to adapt to the cold without needing technology of any kind, some gained by evolution, some just by using common-sense tactics such as huddling together, nothing more is needed.

-hominids regularly changed the fur they were wearing, which could make lice adaptation to clothes slower (not very likely).
-hominids left Africa later than thought.

The first one is indeed a bit unlikely unless they threw them away on a whim after minor usage.

The date hominids left Africa(in more modern times) is increasingly being pushed back as dna evidence etc. is being acumulated. Slowly, to be sure, but still.....

How do you know to what extent an animal relies on its various cold protection mechanism?

For example, smaller mammals and birds are at a greater degree exposed to the cold due to surface area considerations, so not having enough in the way of fur or feathers given their size would hamper them a great deal and therefore they would need more reliance on other methods. Larger creatures with vast sources of blubber/fur  etc. would be less inconvenienced.

[JeuneKoq]

Your last post made 2 false assumptions. I was not stating at all that one had to develop other traits such as dark skin in order to be better able to adapt to consumption of african fruits. All I had said was that IF it really took such a very long time to adapt to eating african or non-african fruits  after switching to the relevant climate, then, obviously, other climatic adaptations, such as darker skin etc., would have in the meantime taken place. Merely a question of length of time, not a requirement of adapting to different foods.


2nd false assumption was that I was focused on the split between humans and apemen. I merely gave a vague  example, but my whole point was that this absurd notion re better adaptation to african fruits  did not really hold water if our remotest ancestors were not based wholly  in Africa for aeons. Turns out, one of our remotest ancestors, Dryopithecus lived all over the Old World, not just Africa.Homo Erectus has been found in many places outside Africa, right up to Java etc. etc.

"It's quite simple. For us humans to be all adapted only to African foods, we would also have to be adapted to Africa in other ways, such as by having darker skin-colour, or longer limbs by comparison to the body(a heat-loss mechanism that  Sub-Saharan Negroes take advantage of) etc.etc. We(non-Africans) do not have these characteristics, ergo we are not specially adapted to african foods."

"For example, were our  remote ancestors always in Africa even  30 million years ago? Possibly not"


You should understand now why I might've been misguided by the way you presented your idea. I mean, there was no way anyone could know you were talking about the separation of humans and "apemen", and not hominids and apes.

[PaleoPhil]

A hunch. It seems to me that evolution would have made it  relatively easy for species to adapt to different foods, as continued survival was so important. If it were more difficult, then one would have expected the Neanderthals to spend little time on the glaciers and go migrating to warmer climes.

Interesting hunch, and I've wondered about how much of a factor regional adaptations are too. Yet adapting to a new food is not the same thing as losing an existing adaptation to a food. From what I've read, once species are well adapted to a food, they don't tend to lose that adaptation for a long time to come, especially if there are microbes that help them utilize the food, and particularly when the food does not contain high levels of toxins, such as with fruit, which you yourself have pointed out multiple times. This would help explain how the Inuit were able to gorge on berries in the summer without a problem from the carbs. It also may help that mother's milk tends to be fairly carby (I have seen reports of roughly 40% carbs on avg, though it varies depending on the mother's diet and other factors), thus keeping a carby element in every diet, along with fresh liver and other sources.

BTW, I read that the most northerly Neanderthals and others didn't live on the glaciers. Rather, they lived near them, in the grass-lush areas fed by the mineral-rich waters of melting glaciers. It's a minor point, but I know that you value precision in your language, so I thought I'd try to help.

I do know about the Fuegians and also the Ice Man Wim Hof. Through them and my own personal experience I know that some cold adaptation is possible, even in the very short term. JeuneKog and Iguana were also correct that the Fuegians also used other warming strategies besides diet, like fire, and also squatting, huddling, and animal skins in the coldest weather, and also tended to stay near the coasts, benefiting from the warming effects of the ocean. It remains to be proven that the partial cold adaptation they developed made tropical fruits a harmful food for them (or any other population).

I know it's only an n=1, but I've actually found that since I learned of a way to improve my carb tolerance somewhat and incorporate more carby and prebiotic-rich foods into my diet, including some tropical fruits (and my past comments show I was skeptical of the degree of tropical-fruit love of the Instinctos and Wai dieters--I still think they may tend to overdo it and I don't think that tropical fruit are a necessity for reasonably good health, but I feel less strongly about it now and I understand better some of the logic behind their claims) that my cold tolerance has actually improved, rather than worsened, and my body temperatures throughout the day tend higher (granted there is the confounding factor of my cold-training, but it is much less intensive than what Wim Hof does). It wasn't something I would have expected in the past, because when I first greatly increased my fat intake and greatly lowered my carbs, I felt warmer (but that effect gradually wore off and I slowly became colder again). There are few people on this planet more Europid than me. If I can find a way to tolerate some tropical fruits, then I suspect that most people can, though this is also just a hunch. Who knows what fate will befall me down the road.

I do not claim that Europids, as a whole have a higher body-temperature than Negroids. But perhaps a few Europids have some Neanderthal characteristics which help them to withstand heat more? it is simple logic. I was pointing out that if it takes such a long, difficult effort to adapt to African or non-African foods or whatever, then other physical changes caused by adaptation to the different climates would have also occurred by then as well.

Pardon me, but now I'm confused. Do you think "it's relatively easy for species to adapt to different foods" or that "it takes such a long, difficult effort to adapt to African or non-African foods or whatever"?

One reason I'm a bit skeptical of your hunch is that I have a higher-than-avg level of known Neanderthal genes, and below-avg glucose tolerance, yet I'm nonetheless able to eat some tropical fruits and have been eating more of them in recent months, and my overall health markers were actually improved in my last lab test. Maybe this only applies to me, but then again, maybe not. When I see other Europids, such as Brady,  Danny Roddy, Yuri, Yuli, Miles, Lowenherz, Stas86, Klowcarb, and others struggling in the longer term with VLC/ZC/keto and reporting improvements after moderating their diets, plus accumulating scientific research and my own experience, it adds up to be enough to admit that my hunch was wrong in my early comments of this forum that humans, or at least Europids like me, might be best described as facultative carnivores. I think you argued at the time that omnivore was a more accurate descriptor (perhaps in part because you were focused with arguing against William and other VLCers)? If so, I think you were right and I was wrong, assuming no big contradictory revelations in future scientific research.

[TylerDurden]

BTW, I read that the most northerly Neanderthals and others didn't live on the glaciers. Rather, they lived near them, in the grass-lush areas fed by the mineral-rich waters of melting glaciers. It's a minor point, but I know that you value precision in your language, so I thought I'd try to help.

I am not disputing that some Neanderthal variations lived in the Middle-East etc. However, at least some/many  of the more northerly Neanderthals do indeed  seem to have lived in/on the glacial areas during Ice-Age Europe, far away from any non-glacial areas, given permanent settlements found there.

I do know about the Fuegians and also the Ice Man Wim Hof. Through them and my own personal experience I know that some cold adaptation is possible, even in the very short term.

I find Wim Hof fascinating. Thanks for reminding me re him, I think you brought him first to my attention ages ago. There was a wonderful SF story by Poul Anderson "The Sensitive Man" which describes a possible future in which humans are able to fully control their heart-beat or enhance their senses and basically control every normally automatic aspect of their body to the point where they can attain amazing feats of  superhuman strength etc.

Pardon me, but now I'm confused. Do you think "it's relatively easy for species to adapt to different foods" or that "it takes such a long, difficult effort to adapt to African or non-African foods or whatever"?

No to the first point if it involves very widely different foods(ie from meats to grains).And no to the 2nd point as types of food are more important. I am sure that my body can easily deal with African nonpoisonous berries than cassava for example.

When I see other Europids, such as Brady,  Danny Roddy, Yuri, Yuli, Miles, Lowenherz, Stas86, Klowcarb, and others struggling in the longer term with VLC/ZC/keto and reporting improvements after moderating their diets, plus accumulating scientific research and my own experience, it adds up to be enough to admit that my hunch was wrong in my early comments of this forum that humans, or at least Europids like me, might be best described as facultative carnivores. I think you argued at the time that omnivore was a more accurate descriptor (perhaps in part because you were focused with arguing against William and other VLCers)? If so, I think you were right and I was wrong, assuming no big contradictory revelations in future scientific research.

I never saw this as a  "right" or "wrong"  sort of issue. Some time after rawpaleoforum got going, there was a flood/massive influx of raw, zero-carbers  who dominated the forums to such an extent that, at one point, I was actually asked to remove the raw omnivore and some other "carby" forums as they were so inactive. Now, it's the other way around, and the RZCers are the new minority. Right from the start, I agreed with Craig Bates that we needed to include as many different RVAF diet paths as possible so that all viewpoints within the community would be favoured. I admit my own bias against 100% raw veganism and fruitarianism is against this ideal, but nobody's perfect. At any rate, because people now have all sorts of weird health-problems, such as EMF sensitivity etc., it is unrealistic to assume that any one limited dietary approach will solve  absolutely all problems, so we wanted to offer as many possible RVAF dietary paths as we could, with people, of course,  being encouraged to look elsewhere as well  if  such RVAF diets did not solve all their health-problems. I am now rather defensive when people attack raw, zero-carb,  as a result of wanting to protect the underdog and provide a balance of views.

My own experience with RZC had good bits and bad bits. I may have to try eating RZC again when I can guarantee a source of raw wild organ-meats as well, just to see if I can easily break the 3-6 week barrier this time, with no setbacks. I have had to admit that when I am in ketosis, such as when water-fasting or eating only raw animal foods, that my concentration/alertness levels are much, much higher.

[PaleoPhil]

I am not disputing that some Neanderthal variations lived in the Middle-East etc. However, at least some/many  of the more northerly Neanderthals do indeed  seem to have lived in/on the glacial areas during Ice-Age Europe, far away from any non-glacial areas, given permanent settlements found there.

My clarification was much more minor than that. What I meant is, and perhaps what you meant but was not fully clear in your wording, was that they did not live literally on the glaciers, but adjacent to them, benefitting from the water runoff from them, which fed the grasses, which fed the animals, which then fed the hominins.

I find Wim Hof fascinating. Thanks for reminding me re him, I think you brought him first to my attention ages ago. There was a wonderful SF story by Poul Anderson "The Sensitive Man" which describes a possible future in which humans are able to fully control their heart-beat or enhance their senses and basically control every normally automatic aspect of their body to the point where they can attain amazing feats of  superhuman strength etc.

It probably was me. Fascinating stuff from Poul Anderson. I suppose Wim is something of an example of his Sensitive Man, for Wim can indeed control some of his bodily functions, such as his immune system and body temperature (as can some Tibetan monks, from whom Wim learned).

No to the first point if it involves very widely different foods(ie from meats to grains).And no to the 2nd point as types of food are more important. I am sure that my body can easily deal with African nonpoisonous berries than cassava for example.

OK, though tropical fruits, such as the fig example, seem to be more the topic of the OP and they don't appear to require nearly as much adaptation even in their raw state and I don't think it would be particularly controversial to say in scientific or most other circles that Europids are still fairly well adapted to eating figs and other tropical fruits and many do eat them without problems. Of course, a minority do experience problems with them even in small amounts, which doesn't mean that applies to all.
 
I share your bias against 100% raw veganism and fruitarianism and agree that diets won't solve all problems.
 

I have had to admit that when I am in ketosis, such as when water-fasting or eating only raw animal foods, that my concentration/alertness levels are much, much higher.

That also occurs during fasting and starvation and I have seen it argued that ketosis is a sort of pseudo-starvation.

Your serving as the voice of the underdog does at least promote discussion.

[TylerDurden]

My clarification was much more minor than that. What I meant is, and perhaps what you meant but was not fully clear in your wording, was that they did not live literally on the glaciers, but adjacent to them, benefitting from the water runoff from them, which fed the grasses, which fed the animals, which then fed the hominins.

What I meant was that some of the Neanderthals lived in glacier-bound areas such as Britain and Scandinavia etc. I was under the impression that no grasses lived in the glacier-ridden areas, but maybe I am a hopeless romantic or something.....

OK, though tropical fruits, such as the fig example, seem to be more the topic of the OP and they don't appear to require nearly as much adaptation even in their raw state and I don't think it would be particularly controversial to say in scientific or most other circles that Europids are still fairly well adapted to eating figs and other tropical fruits and many do eat them without problems. Of course, a minority do experience problems with them even in small amounts, which doesn't mean that applies to all.

I also do not see tropics-adapted peoples having lots of problems digesting fruits from more northern climes, either.
 

I share your bias against 100% raw veganism and fruitarianism and agree that diets won't solve all problems.

I would not mind including them here  minus the more extreme animal-rights-related issues and the fact that they might too easily overwhelm this forum given their much bigger dietary popularity.

[JeuneKoq]

You failed, of course, to address my point which was that the various arctic animals must use a multiple number of additional tactics to adapt to the cold, some of which (such as "huddling") have also been   practised by humans for aeons. Many cold-dwelling mammals, especially the very small ones, do not have more than a very  thin fur layer and cannot realistically maintain more than that, so need much more than just fur in order to survive. And it's not just feathers for birds, some mammals need blubber instead of fur. Plenty of other  species have a variety of  widely different cold-adaptations such as great white sharks which have the ability to retain heat in parts of their bodies circulatory systems, allowing them to survive in colder waters than most other shark species.

Blubbers are mainly used by sea animals and mammals, not land mammals (like us). I already mentioned the thick layer of fat used by sea mammals. I am also very aware of all the various cold protection mechanism, but it should be clear to most by now that land mammals from northern regions all use either fur or feathers as a principal defence against heat loss. And the colder the environment is, the thicker a specie's insulating protection will usually be. I've got my extra furry Lapland dog and Norwegian cat as evidence.

There is no point in trying to minimize the importance of such obviously vital mean of insulation.

Incorrect. True hairless rats, for example, just need to compensate by adopting a much higher  body-temperature. Simple as that.

Are you referring to the naked mole-rat?

Naked mole-rats are native to Est-Africa, hardly the coldest place on Earth. Their underground habitat is, of course, fresher to some extent, but unlike any other mammals on this planet, naked mole-rats are thermoconformers, which means they can adjust their body temperature to the surrounding temperature: if it gets warmer, they warm up; if it gets colder, their body temperature declines. Some even consider them to be the closest thing to a cold-blooded mammal. Pass a certain limit, they will start using other means of thermoregulation such as huddling if too cold, or retreating in deeper burrows if too warm.

The point is, we humans are not thermoconformers. Our body is also a lot more massive, and when living in Northern climes it usually is confronted to climatic events such as wind, rain and snow, unlike underground Est-African naked mole-rats.

No they did not have to use artificial heat-generating mechanisms in order to survive. They were already able to survive without those, it was merely a matter of comfort to use such extras. And your point  re temperatures is not exactly right. The annual average Fuegan temperature of 5.3 degrees Celsius mirrors that of the average annual temperature of the whole of Siberia! In other words, large parts of every  year were spent by the Yaghans in freezing, subzero temperatures. As regards the modern East Asians, their height has been increasing heavily in the last few decades solely due to a change in diet. In the palaeolithic past, before the Neolithic era, they were much smaller. And, anyway, one does not need to be as short as the Yaghans were in order to survive arctic climates. The Neanderthals were slightly taller than the Yaghans and did just fine for countless millenia  until early modern humans arrived and wiped them out.

My mistake on Tierra Del Fuego's climate. I recall wikipedia stating that they had "long, wet, relatively mild winters", but seeing that the average winter temperature is around 0*C, and that snow has happened in Summer, I am left quite impressed of the Yaghan people's cold adaptation feat.

Having said that, I think you overestimate them regarding the use of fire and grease. I will also come back on the concept of "comfort" later.

For example, wiki says Yaghan cuddled around fires whenever possible, even in their boats, and often sheltered in rock formations.

Unless you've thoroughly studied the Yaghan people, or have met them in person in their environment, how can you tell if they are using these artificial methods of warmth for pure leisurely comfort, or for survival?

Ah, it is very clear that you are not all that familiar with survival techniques, let alone the survivalist philosophy. You are approaching everything from the viewpoint of a modern human, stagnating in a settled culture, along with central heating etc. Obviously, modern humans, if they spend all their lives in  centrally-heated buildings, always have access to hot water etc., they are unlikely to suddenly thrive, if suddenly paradropped naked into Greenland. On the other hand, if their descendants were forced to live their  whole lives in subarctic climes with little assistance, one can be sure that they would begin to start developing  adaptations to the cold quite soon, and more permanent adaptations over many generations, even without the aid of technology.

More to the point,my father once told me of how when an acquaintance of his was caught by a blizzard in Norway, the guy built a snow-cave and sheltered therein. It seems snow is a very effective insulator/heat-retainer:-
http://www.motherearthnews.com/diy/snow-caves-and-winter-shelters-zmaz82ndzgoe.aspx

The obvious point is that there are multiple methods of adapting to the cold without needing  technology.

Interesting how easy it is to misjudge people.

I've been considering the idea of testing and pushing my limits of cold resistance, since our talk about cold adaptation and the Yahgans some months ago. It made me think that if Caucasians had characteristics that suggested partial adaptation to colder environments and low sunlight, we might as well try and develop these characteristics in a more advanced/complete way.
So I have been going on long walks in the forest with my Lapland dog during the Autumn and Winter months, wearing nothing else but sports shorts. I have found that I can feel rather comfortable in the cold until 5*C if I don't stay static for too long, even when raining, and I can still manage till 3*C if I keep active. Beyond that I usually experience signals from my body such as goose bumps and shivering that indicates it's getting too cold, or that my energy levels are now depleting fast. At least that's the way I take it.
I also tried to sleep with the least covering fabric possible, but often woke up before dawn, and thus lost a lot of sleep.

Bare in mind that my thyroid is pretty low, and that I'm still on a transitional diet, so my feats may not seem relevant at all in light of other raw dieters or people with healthy thyroids. Well, perhaps I shouldn't exhaust my thyroid even more...

I recently took a wild edible class, as I wanted to add more wild plants into my diet, and am planning on getting my hunter's licence to hunt with a bow or spear. I like outdoors, I like picking my own food.
I might not have read the "survivalist manifesto", or even know about it's philosophy, I might not be totally ready to be para-dropped in Greenland, but I am certainly not one to praise the marvels of modern comfort.

Now, about your second statement, don't you think the man who built himself an igloo, like any handy survivalist, must've been wearing winter clothes, aka technology? I doubt he was out for a naked walk down the lakes of Norway.

They were already able to survive without those, it was merely a matter of comfort to use such extras.

Pillows  stuffed with feathers etc. is a technological improvement not designed for survival per se, but for increased comfort in our modern, decadent world.

All beings either search comfort, or seek ways to extend their comfort zone when this one is being challenged.

What is comfort?

Actually, what is the opposite of comfort? Discomfort, fear, pain, stress, danger. When an animal is in discomfort, it usually means that its life is somehow in danger.
When hungry, the animal fears it will starve. Comfort is when the animal finds food. When warm, it might suffocate. Freshness is therefore comfort to it. If cold, the animal feels stress that pushes him to seek warmth, or "comfort". There are various degrees of comfort, as there are various degrees of discomfort, or danger.
Some people might feel quite comfortable in 5*C temperatures, while others might feel cold. Our comfort zone can also be expanded with experiences and getting accustomed, until a certain vital limit. Perhaps fires, shelters and animal grease are not futile (aka wasteful) means of comfort to Yaghans, but necessary means of survival.



This discussion started on the topic of "Which habitat is most optimal/natural to humans?".

My current position is that any place where humans are capable of surviving without the use of technology, all year round, is man's natural habitat. I think people can choose if they want to live in the most comfortable, welcoming environment to modern humans, with the mildest climate and plenty of food variety, or re-enact the species' pressure (probably linked to rising population density in a given area) to expend to less comfortable climes, and either progressively move to rougher places as the previous one becomes "too" comfortable, or remain in their not-so-mild/not-so-bad home.

I'm considering the idea of one day moving to a place such as South Europe where winters might be more tolerable, but still challenging enough to stimulate my body's natural cold resistance.

[TylerDurden]

Blubbers are mainly used by sea animals and mammals, not land mammals (like us). I already mentioned the thick layer of fat used by sea mammals. I am also very aware of all the various cold protection mechanism, but it should be clear to most by now that land mammals from northern regions all use either fur or feathers as a principal defence against heat loss. And the colder the environment is, the thicker a specie's insulating protection will usually be. I've got my extra furry Lapland dog and Norwegian cat as evidence.

In all honesty, there is no point in trying to minimize the importance of such obviously vital mean of insulation.

Again, you are missing the point. Many arctic-dwelling animals do not have the luxury to grow a vast amount of fur, especially very small mammals. Those with thin fur or not enough feathers per body  have to adopt numerous other cold-adaptation tactics in order to survive. And I have already extensively, laboriously,   pointed out that many  other tactics can easily get the body to adapt to cold environments without the use of fur. Besides, evolving fur is a lengthy evolutionary process compared to, say, boosting the average human body temperature  by an extra 1  or 2 degrees Celsius.There are issues also with the notion of fur being used to protect against the cold. For example, chimpanzees have fur yet live in hot climates. Then scientists have suggested that one reason why humans lost fur was in order to reduce the prevalence of disease-carrying parasites living in the fur such as ticks etc.Another reason for not having fur is possibly sexual selection as bare skin would have been considered more attractive than fur-covered skin.So, while other cold-adaptation methods are very easy to adopt such as making snow-caves or huddling or raising average human  body-temperature etc., re-evolving fur is likely to be the most complicated, most evolutionarily lengthy option. More to the point, when ancient hominids entered subarctic areas before the advent of clothing, why did they not then and there evolve fur on their bodies? Perhaps re-evolving fur would have been a hindrance as regards  natural selection?

Are you referring to the naked mole-rat?

No, of course not. The true hairless rat is the result of some mutation in rats which occurs every now and then. The rat simply compensates for the lack of fur by increasing its metabolic rate and its average body-temperature. Other species with fur  occasionally have such mutants and I am sure they produce similiar cold-adaptation tactics to survive.

Having said that, I think you overestimate them regarding the use of fire and grease. I will also come back on the concept of "comfort" later.

For example, wiki says Yaghan cuddled around fires whenever possible, even in their boats, and often sheltered in rock formations.

Unless you've thoroughly studied the Yaghan people, or have met them in person in their environment, how can you tell if they are using these artificial methods of warmth for pure leisurely comfort, or for survival?

The Yaghans are also mentioned as loving to sleep outdoors most of the time. And their women loved to swim in the antarctic waters, not things one does if one is purely striving to survive. The business of sheltering in rock-formations makes sense if the Yaghans were expecting a powerful storm, and that part of the world is prone to significant storms sometimes.

The notion re Yaghans building fires on their boats seems less a necessity to keep warm and more a desire to keep flames going for as long as possible so as to be able to start fires elsewhere. For hunter-gatherers without matches or even tinderboxes, starting fires, especially in a cold, wet climate, must have been rather complicated.

The point about fires being essential for survival falls flat when one considers that they must have spent lots of  time hunting or foraging on land  without having a fire right next to them at all times.So, the use of  fire was a means of comfort, not an essential tool that would have led to their extinction if they had never used it at all.

Interesting how easy it is to misjudge people.

I've been considering the idea of testing and pushing my limits of cold resistance, since our talk about cold adaptation and the Yahgans some months ago. It made me think that if Caucasians had characteristics that suggested partial adaptation to colder environments and low sunlight, we might as well try and develop these characteristics in a more advanced/complete way.
So I have been going on long walks in the forest with my Lapland dog during the Autumn and Winter months, wearing nothing else but sports shorts. I have found that I can feel rather comfortable in the cold until 5*C if I don't stay static for too long, even when raining, and I can still manage till 3*C if I keep active. Beyond that I usually experience signals from my body such as goose bumps and shivering that indicates it's getting too cold, or that my energy levels are now depleting fast. At least that's the way I take it.

Hmm, sorry. You are obviously  rather creative.

I also tried to sleep with the least covering fabric possible, but often woke up before dawn, and thus lost a lot of sleep.

Bare in mind that my thyroid is pretty low, and that I'm still on a transitional diet, so my feats may not seem relevant at all in light of other raw dieters or people with healthy thyroids. Well, perhaps I shouldn't exhaust my thyroid even more...

I have come across several anecdotal reports from RVAFers who have said that their cold-intolerance steadily went up after years of going RVAF. Some cited better blood-circulation as being the reason for this.In my own case, my glandular system is probably still a bit fouled up due to suffering decades of ill-health in the past, so maybe I am  somehow over-generating body-heat for some reason(hyperactive adrenal or thyroid?).

At any rate, I have seen some impressive things, such as this:-
https://aftermathnews.wordpress.com/2013/01/20/hardy-siberian-children-boost-their-immunity-with-buckets-of-cold-water-in-minus-25c-weather/

I recently took a wild edible class, as I wanted to add more wild plants into my diet, and am planning on getting my hunter's licence to hunt with a bow or spear. I like outdoors, I like picking my own food.
I might not have read the "survivalist manifesto", or even know about it's philosophy, I might not be totally ready to be para-dropped in Greenland, but I am certainly not one to praise the marvels of modern comfort.

Hmm, I am stuck in a capital city for a variety of reasons. Living in a log-cabin away from it all in the wild  does appeal, though.

Now, about your second statement, don't you think the man who built himself an igloo, like any handy survivalist, must've been wearing winter clothes, aka technology? I doubt he was out for a naked walk down the lakes of Norway.

Hmm, he happened to be wearing ordinary clothes, as I recall, as he was driving a car at the time  until it broke down. However, in prehistoric times c. 600,000 years ago, I am sure such snow-cave-makers  would have been starkers.

All beings either search comfort, or seek ways to extend their comfort zone when this one is being challenged.

What is comfort?

Actually, what is the opposite of comfort? Discomfort, fear, pain, stress, danger. When an animal is in discomfort, it usually means that its life is somehow in danger.
When hungry, the animal fears it will starve. Comfort is when the animal finds food. When warm, it might suffocate. Freshness is therefore comfort to it. If cold, the animal feels stress that pushes him to seek warmth, or "comfort". There are various degrees of comfort, as there are various degrees of discomfort, or danger.
Some people might feel quite comfortable in 5*C temperatures, while others might feel cold. Our comfort zone can also be expanded with experiences and getting accustomed, until a certain vital limit. Perhaps fires, shelters and animal grease are not futile (aka wasteful) means of comfort to Yaghans, but actual means of survival.

I have seen humans, and heard of stories about humans, who have exceeded standard expectations as regards limits, all the time. I have also been in the sort of caves that palaeolithic hunter-gatherers would visit in Europe and these were bloody cold, even taking animal-fur-wearing into account. In the case of the Yaghans, they had c.12,000+(?) years, and maybe more in Siberia beforehand(?), to adapt to a cold environment.

This discussion started on the topic of "Which habitat is most optimal/natural to humans?".

My current position is that any place where humans are capable of surviving without the use of technology, all year round, is man's natural habitat. I think people can choose if they want to live in the most comfortable, welcoming environment to modern humans, with the mildest climate and plenty of food variety, or re-enact the species' pressure (probably linked to rising population density in a given area) to expand to less comfortable climes, and either progressively move to rougher places as the previous one becomes "too" comfortable, or remain in their not-so-mild/not-so-bad home.

I'm considering the idea of one day moving to a place such as South Europe where winters might be more tolerable, but still challenging enough to stimulate my body's natural cold resistance.

Southern Europe, huh?! The winters in northern Italy are ghastly. There is a rainy season from November to April, more or less. Recent years have seen flooding all over Liguria and many other parts of Northern Italy. My own property there has had trees falling all over the place - I hope this global warming is as absurd as I used to think it was.
Choose Northern Greece. They are desperate for cash and willing to sell off a lot for next to nothing!

[PaleoPhil]

My opinion on cold adaptation probably lies between the two poles (pardon the pun ). I generally find actionable things I can do to be the most interesting and fruitful (another pun) for both me and my friends and family. The most interesting thing to me is that Wim Hof, Tibetan monks, Albert Szent-Györgyi, Ray Peat, Ray Cronise, Jack Kruse, Swedes, Fuegans, Homo erectus, Neanderthals and others have shown that the ability of hominins to adapt to cold and heat is greater than most people imagine.

The naked mole rat may actually provide some clues on how to live a healthier, more vibrant life, and slow or even some day reverse aging: http://raypeat.com/articles/articles/co2.shtml

Ironically, my hunch is that tropical fruits in moderation help with both temperature adaptation and slowing aging.

[RogueFarmer]

Jeune Koq, you mention jogging and feeling cold at -5 celsius and being fine above freezing, even when it's raining. What climate do you live in? I am having trouble finding this information on the internet, but in my personal experience the weather that plays between freezing and not freezing is actually much more uncomfortable than the weather that just stays way bellow freezing all the time. This is largely because in the former case there is much more humidity in the air.

One winter I lived in a heated cabin in Southern Ohio. It was a very rainy winter, it felt very cold, i shivered a lot and even developed a slight case of walking pneumonia which is one of two times I ever suffered from pneumonia symptoms. Two winters later, the winter before last, I lived in Northern Michigan. I lived in a insulated loft in a closed barn without heat for 2/3 - 3/4 of that winter after I became disgusted with the smoke that would sometimes waft out of the wood stove. The temperature went above freezing on two occasions that winter for a few hours. I shit you not 17 degrees felt warm, almost like spring time. I would walk 6 miles at 4 in the morning when it was -20 to -30 fahrenheit (that's -29 to -34 celsius) with the wind howling at 20-30 miles per hour. I wore jeans with cotton long underwear, a shirt and a couple wool sweaters with a coat, a hat and gloves. I had a -30 degree rated sleeping bag I used as a blanket and slept with two long hair cats. Never did I feel acutely cold. Never did I shiver. Not until the spring rains came lol. Never did I get sick that winter.



Tyler Durden I think you still keep saying that smaller people are more adapted to the cold and have less surface area to body mass. Albeit I can't find where you said it but I think you said it. Smaller people have more surface area to body mass.

http://en.wikipedia.org/wiki/Bergmann's_rule

I feel like smaller size in arctic regions has more to do with limited food supply than it does with smaller bodies being more suited to the cold.

[PaleoPhil]

Tyler and Roguefarmer, do you set a thermostat in your home or workplace? If so, what temperature do you set it to?

[TylerDurden]

Tyler Durden I think you still keep saying that smaller people are more adapted to the cold and have less surface area to body mass. Albeit I can't find where you said it but I think you said it. Smaller people have more surface area to body mass.

http://en.wikipedia.org/wiki/Bergmann's_rule

I feel like smaller size in arctic regions has more to do with limited food supply than it does with smaller bodies being more suited to the cold.

Allen's rule does however state that smaller limbs allows for less surface area and so better cold-adapation. That was the one I was thinking of, but you are right I must have been overgneralising like you said.

http://anthro.palomar.edu/adapt/adapt_2.htm

The idea behind Bergmann was not that great size protects against cold but that a more compact body with a large body-mass per size was needed. So, a stocky, short Neanderthal, weighing a lot more than a tall, slenderer Cro-Magnon, would have been better protected against the cold.

[TylerDurden]

Tyler and Roguefarmer, do you set a thermostat in your home or workplace? If so, what temperature do you set it to?

I have no choice but to use a thermostat at 20 degrees Celsius outside the summer months  as I do not live alone. Were I alone, I would likely use a thermostat  at, at most,  10 degrees celsius in the dead of winter(5 is minimum so as to avoid bursting the pipes with ice).

[JeuneKoq]

And I have already extensively, laboriously,   pointed out that many  other tactics can easily get the body to adapt to cold environments without the use of fur.

Yes, I understand, but it seemed to me that these tactics were often comparatively less efficient, and secondary to having a coat of fur, or feathers, or grease.
I suspect that Neanderthals, if not furry or dressed, must've stocked some protective grease in specific parts of their body, such as the belly. Yaghans seem rather chubby, generally speaking.

Besides, evolving fur is a lengthy evolutionary process compared to, say, boosting the average human body temperature  by an extra 1  or 2 degrees Celsius.

Technically, we are as furry as chimpanzees. Our fur is simply a lot shorter and thinner on most part of our body. There are some rare cases of people suffering from a genetic disease called terminal hyperthrichosis, and are covered in thick fully grown hair. There were numerous cases of hypertrichosis throughout history with various degrees of hairiness.

http://en.wikipedia.org/wiki/Hypertrichosis

 This means that growing fur could hypothetically be rather easily achievable for most humans.

The question you raised is then legitimate: why did we not simply grow fur when we entered colder climes? Perhaps growing fur was more detrimental to us than otherwise, since adventurous humans would've selected individuals most resistant to their new environment.

There are issues also with the notion of fur being used to protect against the cold. For example, chimpanzees have fur yet live in hot climates.

Nights can be very fresh in most parts of Africa. I have already given the example of my witness of Senegalese people wearing winter clothes (rain coat, gloves, woolly hat) at night 

Then scientists have suggested that one reason why humans lost fur was in order to reduce the prevalence of disease-carrying parasites living in the fur such as ticks etc.Another reason for not having fur is possibly sexual selection as bare skin would have been considered more attractive than fur-covered skin.

Don't forget our ability to run for extremely long periods of time thanks to our sweaty bare skin!

No, of course not. The true hairless rat is the result of some mutation in rats which occurs every now and then. The rat simply compensates for the lack of fur by increasing its metabolic rate and its average body-temperature.

The true hairless rats are, however, still more sensible to cold than regular rats (or so it seems by the recommendations of owners regarding the choice of warmer cages, and socks to snuggle in) , and their adopted tactics of cold protection are more energy consuming, which means they must be fed a more protein- and fat-rich diet.

http://theophanes.hubpages.com/hub/Common-Furless-Rat-Health-Problems

If ancient humans from northern climes really lived bare, they must've compensated with a more intense hunting activity during the winter months.

The Yaghans are also mentioned as loving to sleep outdoors most of the time. And their women loved to swim in the antarctic waters, not things one does if one is purely striving to survive. The business of sheltering in rock-formations makes sense if the Yaghans were expecting a powerful storm, and that part of the world is prone to significant storms sometimes.

The point about fires being essential for survival falls flat when one considers that they must have spent lots of  time hunting or foraging on land  without having a fire right next to them at all times.So, the use of  fire was a means of comfort, not an essential tool that would have led to their extinction if they had never used it at all.

I recall that Yaghan women did not bath in the sea just for fun, but to fish.

I always feel warmer when I am active. Going hunting usually means being active most of the time. There would also simply be no time for making fires, and it would warn potential preys of their presence.

Maybe the absence of fires would not necessarily imply the extinction of all Yaghans, but could possibly mean a great deal of them would go very weak. They would probably do better on a RPDiet though, who knows 

Southern Europe, huh?! The winters in northern Italy are ghastly. There is a rainy season from November to April, more or less. Recent years have seen flooding all over Liguria and many other parts of Northern Italy. My own property there has had trees falling all over the place - I hope this global warming is as absurd as I used to think it was.

Choose Northern Greece. They are desperate for cash and willing to sell off a lot for next to nothing!

I was first thinking about other countries such as Spain or Portugal, but Greece doesn't sound bad at all!

Maybe all European RPDieters could put their money together to buy a big island, Sentinel style, and grow various native and soon-to-be-naturalized edibles, forage for sea food, and hunt game inland. It could be the European RPDF headquarters   

Jeune Koq, you mention jogging and feeling cold at -5 celsius and being fine above freezing, even when it's raining. What climate do you live in? I am having trouble finding this information on the internet, but in my personal experience the weather that plays between freezing and not freezing is actually much more uncomfortable than the weather that just stays way bellow freezing all the time. This is largely because in the former case there is much more humidity in the air.

My cold resistance limit is 5*C, not minus 5*C, and I usually do a mix of walking and jogging when walking my dog. I could do colder temperatures, but only if I jog constantly, or if I am less active for much shorter periods of time.

Belgian climate is usually moist and cold in the winter, when it's not snowing. My father once came back from a trip to Moscow, where the climate was colder but dry, and he told me Brussels actually felt a lot worse because of the humidity.

You seem to be quite resistant to cold. I guess it also has to do with health and energy levels at a given time, and of course what kind of fuel you put in your body.

[TylerDurden]

Yes, I understand, but it seemed to me that these tactics were often comparatively less efficient, and secondary to having a coat of fur, or feathers, or grease.
I suspect that Neanderthals, if not furry or dressed, must've stocked some protective grease in specific parts of their body, such as the belly. Yaghans seem rather chubby, generally speaking.

  The Neanderthals had numerous adaptations to the cold, some certain, some due to guesswork(eg:- a higher average body-temperature). The Yaghans would have had to have had a stocky build to survive the subarctic climes in Tierra del Fuego.

Technically, we are as furry as chimpanzees. Our fur is simply a lot shorter and thinner on most part of our body. There are some rare cases of people suffering from a genetic disease called terminal hyperthrichosis, and are covered in thick fully grown hair. There were numerous cases of hypertrichosis throughout history with various degrees of hairiness.

http://en.wikipedia.org/wiki/Hypertrichosis

I have seen cases of hypertrichinosis. Those cases did not have actual  fur or anything like it, just excessive  hair. To develop real fur would have required a bit longer time to develop, evolutionarily, imo. Besides, humans already have different types of hair on their bodies, depending on location, gender etc., not just one type.

The question you raised is then legitimate: why did we not simply grow fur when we entered colder climes? Perhaps growing fur was more detrimental to us than otherwise, since adventurous humans would've selected individuals most resistant to their new environment.

That is one point I was making, though some cold-adaptation methods are a lot easier to achieve than growing fur.

Nights can be very fresh in most parts of Africa. I have already given the example of my witness of Senegalese people wearing winter clothes (rain coat, gloves, woolly hat) at night 

Hmm, I visited Kenya and it was damned hot at night. I am sure that specific regions such as the Ethiopian uplands are coldish. Still, I will admit I have not been to other regions in Africa.

The true hairless rats are, however, still more sensible to cold than regular rats (or so it seems by the recommendations of owners regarding the choice of warmer cages, and socks to snuggle in) , and their adopted tactics of cold protection are more energy consuming, which means they must be fed a more protein- and fat-rich diet.

So, all humans needed was to eat a more protein- and fat-rich diet like the Inuit in order to survive in arctic climes.

If ancient humans from northern climes really lived bare, they must've compensated with a more intense hunting activity during the winter months.

Yet the Inuit in their igloos used to go around  virtually stark naked all the time because of the heat therein. Perhaps palaeo humans just hunkered down and fasted for most of the winter in dens and shelters.

I recall that Yaghan women did not bath in the sea just for fun, but to fish.

The source I read stated that they loved to swim in general, not just to fish. If swimming in the cold arctic waters  was so very  dangerous to their survival, they would have  presumably stuck to fishing from their canoes(which they did anyway) but would not have bothered to also swim/dive for shellfish.

As regards the Yaghans, it does seem unlikely that they did not know how to make clothes or that they had no resources for making clothes, so their  near-absence of clothing does seem to indicate some adaptation as opposed to just day-to-day survival.

[PaleoPhil]

I have no choice but to use a thermostat at 20 degrees Celsius outside the summer months  as I do not live alone. Were I alone, I would likely use a thermostat  at, at most,  10 degrees celsius in the dead of winter(5 is minimum so as to avoid bursting the pipes with ice).

OK, so if the outdoor temp fell significantly below your preferred 10 celsius, such that your clothing wasn't enough to keep you roughly at that temp, and you needed to stay outdoors and had to stand or sit for some reason (so that you couldn't keep warm by running about), say to carve, distribute and eat food, speak with tribesmembers, or some such thing, then would you adjust with an external warming factor, such as additional clothing or fire?

[eveheart]

... would you adjust with an external warming factor, such as additional clothing or fire?

My body prefers an ambient temperature of 60 F/15 C. In winter, I can keep indoor temperatures in the low 60s, but I have to run a dehumidifier to prevent molds from growing in the walls. In the California style of construction, unheated houses getting moldy is a common problem, as in when the house is vacant. The only time I turn on a space heater is when the outside temperatures are expected to dip to freezing, which is not often.

[PaleoPhil]

I am sure that specific regions such as the Ethiopian uplands are coldish.

Bingo, and those are some of the regions where ancient hominin remains have been found, which is one reason why it's odd that you're objecting so strongly to any mention of Africa. Did you think the temperatures were forever and everywhere super hot in the African Great Rift regions in the past?

So, all humans needed was to eat a more protein- and fat-rich diet like the Inuit in order to survive in arctic climes.

You're aware that the Inuit wear parkas outdoors, right? I suspect that this is another case where you're playing devil's advocate to spur discussion. 

My body prefers an ambient temperature of 60 F/15 C.

Not surprising, and I think most Europids would prefer temps like that over below-freezing temps in an arctic or subarctic region. Humans are amazingly adaptable, yet most of us still prefer temperate, subtropical and tropical temps to arctic.

[TylerDurden]

OK, so if the outdoor temp fell significantly below your preferred 10 celsius, such that your clothing wasn't enough to keep you roughly at that temp, and you needed to stay outdoors and had to stand or sit for some reason (so that you couldn't keep warm by running about), say to carve, distribute and eat food, speak with tribesmembers, or some such thing, then would you adjust with an external warming factor, such as additional clothing or fire?

  I can handle lower temperatures than that. It is just a matter of getting used to it over time. If temperatures were always below 0 degrees Celsius, I would simply find a shelter and warm myself through my own body-heat and that of others'. Obviously, if I had been subjected to very cold environments all the time since birth, I am sure that I would be much hardier and more adaptable  than now.

[TylerDurden]

Bingo, and those are some of the regions where ancient hominin remains have been found, which is one reason why it's odd that you're objecting so strongly to any mention of Africa. Did you think the temperatures were forever and everywhere super hot in the African Great Rift regions in the past?

Early hominids are supposed to have lived in the boiling hot savannahs, not in colder regions.

You're aware that the Inuit wear parkas outdoors, right? I suspect that this is another case where you're playing devil's advocate to spur discussion. 

The point is that the Inuit spend a lot of their time indoors in igloos where it is necessary to be virtually naked because of the heat built up. So they go out to hunt in parkas. No surprise, they are a Neolithic-era tribe with access to fire etc., so would hardly have become adapted to the cold to the extent of being able to move around naked on the snow.

Still, there is now a craze for barefoot running in the snow. Maybe we moderns aren't all that unadapted after all:-
http://running.competitor.com/2013/11/news/new-trend-barefoot-running-in-the-snow_90081

Not surprising, and I think most Europids would prefer temps like that over below-freezing temps in an arctic or subarctic region. Humans are amazingly adaptable, yet most of us still prefer temperate, subtropical and tropical temps to arctic.

Err, Eveheart is Oriental/East Asian(I think??), not Europid.
Wanting hot temperatures is more of a recent phenomenon. It started in the 1960s onwards where British people, for example,  would switch from happily swimming in the cold Northern waters, and go to the sunny Mediterranean. Nowadays, one is looked at as being very odd if one swims in the Atlantic without wearing a diving-suit and carrying a surf-board.Now, the trends are changing yet again,  with people more and more opting for unusual holidays that are not so mainstream as the hot-climate ones.

[PaleoPhil]

So in other words, we like to use shelter to keep the temperatures warmer than in the icy regions
Boiling?   
Humans are able to adapt to heat as well as cold. I am a Europid who is pretty well adapted to both, at least better than I was. I go barefoot in the snow myself sometimes.

If so, sorry Eve, I'll correct that to Eurasian.