Where is humans natural habitat?

Depends on the humans in question. A lad from the Congo may find North Canada not exactly to his taste and an Inuit is gonna get onto his travel agent if he found himself in Dubai. I'd say for Europeans probably southern Europe would work well I reckon?

JuliusCaesar wrote: »

.ie white people absorb Vit D from sunlight much faster and easier than black people, white people have greater cold tolerance etc. There was a Ch 4 programme on race a few years ago which went through this stuff, interesting. Can't remember what the story was for black people born here as obviously we're all very adaptable. I *think* that black people here became Vit D deficient much more easily.

Yea Black and Asian folks in the UK had issues with rickets in the past. In the US IIRC Yanks of African origin up in northern states don't live as long nor are as healthy as their rellies living in the poorer south. One theory is Vit D deficiency. It can be bad enough in those of European ancestry who are office workers, but dark skin really screws with it's production.

Strangely it seems that we have actually evolved for whatever climate...

Yea though there are odd ones there too. Take white skin at higher latitudes. The theory goes that white skin evolved rapidly because of the climate in the first Europeans coming from Africa circa 40,000 years ago. All good except for Tasmanians. Tasmania is also of a high latitude yet they were very dark and they came from Africa 50,000 years ago so Europeans getting white skin is probably something else(probably neanderthal gene exchange). This stuff can happen pretty rapidly too. EG the Inuit of the polar regions have a much higher density of capillaries in the face and hands as a protection against frostbite and that set of genes looks about 15,000 years old. It's odd the Tasmanians in a much longer time didn't come up with pale skin. Clearly selection pressures were higher in the Inuit, or maybe the Tasmanian diet was very high in D? Hard to find info on them as most were hunted like animals by European settlers. There was a bounty on them. Horrible horrible history and crime against humanity there.

Thinking more on this, I think modern humans sapiens sapiens have no real natural habitat as such. This is maybe what allowed us to outcompete our earlier cousins. Maybe it wasn't our advanced tools or our advanced cultural symbolic thought that some have suggested as reasons, or at least not those alone. In any event those came late to the party. We were fully modern for the guts of 150,000 years before most of that came along.

To all intents and purposes we were on parity with Neandertals and other proto humans, especially with the former. They were ahead in many ways. Yet we "won". Why? I'd say our body shape and adaptability. Neandertals were in Europe for 200,000 years. 2000 centuries of ebbing and flowing glaciations and "warm" periods and they adapted and thrived. The apex predator among a fauna of apex predators. They were highly intelligent people with an array of technologies. Wiley wolves with weapons.

We were similar but a lot weaker. Well in body strength in one direction; muscles. Even an adolescent Neandertal would - I think the technical term is - fcuk you right up. A fully grown neanderthal woman had just over the same arm strength in simulations as the male arm wrestling world champion. A fully grown Neandertal man? He is Godzilla, you are Japan. Four times stronger than a strong modern man is around the figure estimated. In a MMA world title fight? Bet heavily on the stocky red haired hairy lad with the big brows. (when they decode the full Neandertal genome, I'm repairing to my shed with a "DIY Cloning kit". We'll make a fortune...)

But our more weedy body adapted for north east Africa required less food and with clothing meant we could go to more places. The heavily built Neandertal were gangbusters in chilly environments, but would have faded away in the heat. They also needed more calories per day to sustain that body. They were limited to the climate they could migrate to and operate in. We weren't. Yea Inuit tend to be stocky cold adapted lads and lasses and Maasai tend to be tall skinny heat adapted lads and lasses, but you find the odd skinny malink Eskimo and fat bastid Maasai And an average Maasai could hang out in Alaska and an average Eskimo could hang out in Kenya. They'd be heat and cold stressed initially, but I'd put money they would adapt. Meh I don't need to place a bet. Look out the window at the "Irish summer". Or remember looking out the window at an Irish white Christmas last year? And there were a few thousand west African folks looking out of their windows at the same Irish snow. Hell I got into a snowball exchange with a guy and his kid from Lagos**. And I felt the cold more than they did

So in the end maybe why we're here and the others are all gone* is that we just don't have a "natural habitat" as such and can use the technology of clothing and other things to alleviate local variations? The one big thing you find in early sapiens sites, the one thing you don't see in any other human tech before us? Needles. To paraphrase an old saying, maybe "a stitch in time saved our line".... Humanity.




*I suspect home erectus was as, or even more locally adaptable(minus clothing) as they left Africa two million years ago and ended up all over the place in all sorts of climates. Not quite to the degree as us, but damned impressive. They seemed to be more flexible. Tough magnificent buggers they were. It would take another two million years before an improved version of erectus came along who was similar in that respect.

** also showed another trait that many ladies will agree with. Men the world over never grow up. Actually IMHO another reason for our success. Humans remain childlike throughout life.

Sea Sharp wrote: »

I would have assumed that the best climate for humans is a climate in which we can survive naked.

That's the thing though. We don't have to and haven't had to for at least 80-100,000 years BP. Throw in the wearing of rough cut animal skins and likely throw that back a further 50,000 years beyond that. Now you could contend that a non naked human is not "natural". Personally I wouldn't, I'd call it part and parcel of being human.

Alternatively, it is whatever the climate in North Africa was 50,000 odd years ago. To the best of my knowledge North Africa was tropical before the ice-age ended. But as mentioned above different gene pools have adapted to different climates so there's no straight forward answer to the OP.

Pretty much this. Even going back 50,000 years BP we would have been dark skinned leaving Africa, only picking the light skinned variants up later.

Thinking more on it... On the cultural front IMH I'd liken them and us the same way I'd liken wolves and domestic dogs. The old cliche of humans being like wolves with knives is an old and hackneyed one, but one that led me to think more on and equate our evolution with that of the wolf and the domestic dog. There are or seem to me to be quite a few parallels.

Wolves and dogs are the same species, or sub species of each other. But there are quite distinct physical and mental/emotional/behavioural differences between them. Wolves are very territorial. They also don't take that well to new members coming into an established pack. They have huge ranges. They are more selective in what they eat. Behaviourally they're very complex in their interactions with one another within the pack. They're also more aggressive, yet at the same time timid to new experiences. They go through the puppy stage and then mature. They're very vocal, but drop the puppy vocalisations as they mature. They're less playful as adults.

Dogs are territorial, but will welcome new members into the pack throughout life. They can survive in smaller ranges. They remain puppies throughout life and are far more playful throughout life. They're less aggressive and more inquisitive when it comes to new experiences. They also retain many more of the puppy vocalisations. They're neotenous wolves, basically wolves that never grow up.

Physically; Wolves compared to dogs are on average bigger, more muscled with higher bone densities. They've got thicker fur and fewer variations in colouration. In the skull the differences are; larger more robust snouts, much bigger teeth and jaws and jaw muscles, slightly bigger brained with heavier skulls and more receding foreheads(see where I'm going with this ). Dogs are less robust, with flatter more puppy like faces, smaller brained and with more variations in colouring. This tends to happen with most examples of domestication. The resulting animal is neotenous, retaining juvenile characteristics throughout life. The experiments in Russia with wild foxes bore this out. You even see broadly similar with animals like cattle.

All this sound familiar when you compare us and previous hominids especially Neandertals? It would be my take that we look and act the way we do and look and act so differently to what went before* because we have evolved and selected each other to be neotenous humans. Humans that never "grew up". Playful and inquisitive throughout life. It might also explain why we and the dog matured alongside one another and why previous humans never had dogs. And why in the modern world wolves are often endangered, other hominids are long gone, yet dogs are among the most numerous mammals on the planet and so are we.





*at the hominid house party we're very strikingly the odd ones out in how we look.

slowburner wrote: »

Intriguing stuff.
Am I right in saying you would liken the Neanderthals to wolves and Modern Man to the domestic dog?

Yep pretty much SB. In very broad strokes anyway.

One question then.
Dogs developed their neoteny through selective breeding - we fostered the characteristics we liked. Then the dogs come to depend on humans for food etc.

Truish. Though Fido can revert pretty quickly. IE the dingo. They don't need us as such, it's just advantageous to be around us and we around them. Plus while we certainly selected traits over time, in the early days I suspect they'd be much more wolf than dog. Our "packs" and hunting strategies are remarkably similar. We were more like wolves in many ways than we are like chimps. Mobile pack hunters who specialised in endurance hunting as well as ambush. It was very much a mutual thing. While we like to think we were aways the proactive partner I would suggest that it wasn't quite the one way street. Wolves, otherwise wild wolves in captivity in zoos and parks but exposed to and interacting with humans start to exhibit domestic like behaviour and appearance even without selectively breeding for those traits. It may have been an excaptation/preadaptation that came into play when we met and went off in a novel direction. The blind watchmaker of evolution reset the time a little kinda thing.

How would this apply to human neoteny? Who bred us and who did we depend on?

We did. We depend on each other and ourselves and maybe neotony was another exaptation that as the group got larger and the connections between those groups got larger fed on that. Highly aggressive territoriality is not great for trade. Oh yes we do the whole war thing, but I strongly suspect if Neandertals had won out and ended up with nukes we'd be in Mad Max world right after. Throw in wolves coming in from the cold and triggering similar and that old jokey question of dog lovers; "who domesticated whom" comes into play. What's interesting is how connected we are to dogs and they to us. If you play a sample of dog vocalisation to a group of people, even non "doggie people" are remarkably accurate at working out the meanings behind the various vocalisations. Play the same group chimp/gorilla/orang vocalisations and they're completely in the dark. We appear to be primed to understand them. Interestingly we're also very good at spotting it in young wolves(and wolves have a slightly different "language").

It's not going one way either. Dogs are very good at following human emotional states. They're also aware of when a human is watching them. If you close your eyes or look away their behaviour changes. Also unique among other animals they understand pointing at things. You might imagine that chimps etc would as they are so close to us, but they don't get pointing at all. Dogs can even watch your eyes and discern you pointing with them. We also get emotional interaction on a biological level. Patting a dog lowers blood pressure and increases mood and does the same for the dog. There was a great set of youtube links on this very subject but I lost them

As for one of the main drivers of this neotony in humans? I'd go out on a limb and say the ladies. Women selected for more neotonous males as an advantageous trait. Even in crappy popular culture this idea has currency. The woman who tames the "bad boy" or the "wild man". Beauty and the beast for my mind has a lot to say about certain aspects of recent human evolution that may be appreciated on the surface. I'd even go so far as to say that's why a large cohort of young women go through the bad boy phase. It's the attraction of being able to "tame" his wayward ways. I'd suggest it's to make him a more neotenous human for the sake of the group. Extremes of that personality of women can even lose interest when they appear to succeed in this. Obviously i'ts far more complex than that and women, depending on cultural environment may select more for the more "mature"(in the sense of non neotenous male) where that is more advantageous. Women who may select more for the hyper aggressive male in times of war etc. Ask why do death row male prisoner get love letters and ften lost of them? This stuff runs deep.

IE MC begs a good question:

Mahatma coat wrote: »

say your at a Nenderthal Sapien get together and yer chattin to some chicks round the fire, would you rather shag the Svelee sallow friendly one or the Monobrowed Stocky One who could break you in half

The monobrowed male is aggressive and can back this up with strength. In an environment where that's an advantage he starts to look a lot better. Better than even one of your "kind". He's close enough in species terms. This would go double if you were in a novel environment where the Neadertal was already adapted for it. This seems to be borne out by the DNA evidence. It seems the Neandertal DNA comes into our mix in the ME/Levant when we first strike out from Africa and the genes flow from Neandertal man to Sapiens woman. How better to ensure your offsprings chances than to get busy with a guy who is "one of the locals".

slowburner wrote: »

My completely uneducated guess is no - because we have repressed any expression of those genes and for them to emerge, they would have to be nurtured to some extent. And is there any evidence of such a development in people over 110 years of age?

Agreed, unless you can find a centenarian out there with big brow ridges and the beginnings of a mid face muzzle. We may even become more neotonous if we live longer. We as modern humans have been getting more and more like that in the last 40,000 yrs(around the time we inexplicably started to live longer).

I have a dim memory that the reason our skulls resemble juvenile chimpanzees' is that ours sacrifices bone density for cranial capacity.

I'd read that too. Slight fly in the ointment though. Neandertals have bigger cranial capacities than moderns on average. The biggest(non pathological) hominid cranial capacity on record belonged to a Neandertal IIRC. And they had much higher bone density with it. even we had slightly bigger heads 60,000 years ago. We've become less robust with time.