Natural and Optimal Human habitat/habitats?

[Anopsology]

CHeck this website out and this theory out and then come back this forum guys!

https://sites.google.com/site/humanhabitatproject/home

 

 

Optimal human habitat? what is it?

[chadn737]

So?

 

I label what I'm doing the reasoning from evidence practice.

 

 

But place them in an environment where they never run, and their healthy life expectancy may well go back down - how would you bet?

 

Because they evolved to live long heatlhy lives based on frequent running, see? They didn't evolve to get eaten by predators, but to escape them. A good healthy life involves some running, for these species. In our case: also dietary citric acid and certain protein composition, sunshine exposure on bare skin, and the like.

 

You seem to have mistaken the direction of argument.

 

 

 

Averages that include death by violence mislead in this discussion. Apparently, by the evidence we have, it was not "exceptional" for stone age humans who were not killed by infectious disease or violence to live to around 70, which is about the same age we expect a reasonably rich person not killed by violence or infectious disease to attain comfortably today if they live well - that seems to have been, and approximately be, the evolved healthy lifespan of our species in a well suited environment.

 

 

 

Not "many" - a few, recent, isolated, and notable. These exceptions are good tests of the rule - nobody is claiming that evolution has stopped, for our species, eh?

 

 

 

SO.....the entire point of this thread is that because humans evolved under a certain set of conditions that those conditions are therefore optimal to a long and healthy life. At this point I really don't know what you are arguing, it seems to flip back and forth between "yes there is an optimal environment for humans" to "this is how humans evolved". The former is an appeal to nature, the latter might be correct, but thats not the point.

 

Sure, exercise is good, sun is good....this doesn't mean that there is an optimal environment or that such an environment is the same as which we evolved under, and thats the entire point. Humans evolved under many conditions and most of those conditions entailed disease, starvation, extreme environments, and violence. Exercise could be achieved by being chased down by a lion....it could also be achieved by running on a concrete track with an ipod. You can pull the latter off anywhere in the world, making the need for a specific environment irrelevant. Read the opening post. This is not merely a discussion of "healthy living", which I agree is shaped by our evolution, but about whether we should be living in a very specific environment, the one which we evolved under. It is this latter claim that I disagree with. What you are describing is not really the same as what I think the OP asks. I don't think one is going to live a healthier life for living in east central Africa as opposed to southern Sweden or Florida. We have evolved a certain set of requirements, but those need not be met by specific environments. Furthermore, the specific environment may not be the optimal. If we can achieve longer lives through artificial environments, then what does that say?

 

Averages that include death by violence mislead in this discussion. Apparently, by the evidence we have, it was not "exceptional" for stone age humans who were not killed by infectious disease or violence to live to around 70, which is about the same age we expect a reasonably rich person not killed by violence or infectious disease to attain comfortably today if they live well - that seems to have been, and approximately be, the evolved healthy lifespan of our species in a well suited environment.

 

 

Death by violence is a natural part of the environment and how we evolved. In fact, it is selective pressures, like violent death, that help drive evolution. When you start factoring out all the nasty bits and start cherry picking the few lucky humans that managed to escape violence, disease, starvation, etc you are left with an overwhelming exception, not the norm.

 

The age of 70 seems entirely arbitrary. Why not 60? Why not 80? Why not 90? Why not 100? We have lots of people living in their 100s. The reason we rely on averages in discussions like this is because there are always exceptions, but exceptions do not prove the rule. If anything, the fact that the average age is now well above 70, despite how "unnatural" our life is, is evidence that taken away from our "natural habitat" we actually do quite well. If we as humans evolved specifically to live to an age of 70, then how do we explain the existence of people in their hundreds? The idea that we evolved to live to a certain age seems to me completely unrealistic, especially when there exists such a wide range. Menopause suggests that we did evolve to live past that point to a degree...at least women evolved that way, but to 70? I just don't buy that claim unless there is some other evidence that suggests as much.

 

Not "many" - a few, recent, isolated, and notable. These exceptions are good tests of the rule - nobody is claiming that evolution has stopped, for our species, eh?

 

 

 

A few? Only because our ability to test such assumptions are limited and have limited us to previously easily testable traits like lactase persistence or sickle cell anemia. However, we are finding increasing numbers of other examples with next generation sequencing and large population studies, such as the aforementioned adaptations to high altitudes.

 

Certainly such adaptations are recent....agriculture is recent....that doesn't make them insignificant.

 

Isolated....if you consider hundreds of millions of people (lactase persistence probably has billions) to be an isolated example, then I suppose you are right, but that is not what I would call isolated.

[overtone]

 

 

SO.....the entire point of this thread is that because humans evolved under a certain set of conditions that those conditions are therefore optimal to a long and healthy life

Not my posts. That's stupid, and already dealt with (running from predators, was the example, above).

 

 

Death by violence is a natural part of the environment and how we evolved.

Nevertheless, it misleads in a discussion of evolved lifespan. Animals evolve to avoid early death by violence, to live healthy and reproductive lives of the best length when not killed by violence. Mayflies, for example. Cicadas. Elephants. Sequoias.

 

 

 

The age of 70 seems entirely arbitrary. Why not 60? Why not 80? Why not 90? Why not 100?

Because we observe that people not killed by infectious disease or violence tend to live about 70 years more or less (Bible, thousands of years ago: "Three score and ten") before age-mediated stuff starts killing them. Not 60, not 80. And that is true of essentially all people we have numbers for, as far back as we can trace - Cro Magnons, say.

 

 

 

If anything, the fact that the average age is now well above 70, despite how "unnatural" our life is, is evidence that taken away from our "natural habitat" we actually do quite well.

We live longer with lethal aging consequences due to modern medical care - but from about 70 on we are afflilcted with them. Medical care survival too is irrelevant to an assessment of our way of life before the natural lifespan - indicated by the onset of age-mediated mortality - kicks in.

 

 

 

If we as humans evolved specifically to live to an age of 70, then how do we explain the existence of people in their hundreds?

Seriously? You're going to go creationist on me one paragraph after invoking "averages"?

 

The idea that we evolved to live to a certain age seems to me completely unrealistic, especially when there exists such a wide range.

As noted, there is no wide range in the onset of age-mediated mortality among the populations of human beings on this planet, now or as far back as we can track.

 

You yourself pointed out the selection for certain genetics that start killing people when they get old. If you put a number on "old", you'll find it's around 70, give or take.

 

Which, however informative, is somewhat tangential. The thread topic was about optimal human "habitat", which I took in a general sense encompassing diet etc.

[chadn737]

Not my posts. That's stupid, and already dealt with (running from predators, was the example, above).

 

 

Nevertheless, it misleads in a discussion of evolved lifespan. Animals evolve to avoid early death by violence, to live healthy and reproductive lives of the best length when not killed by violence. Mayflies, for example. Cicadas. Elephants. Sequoias.

 

 

 

Because we observe that people not killed by infectious disease or violence tend to live about 70 years more or less (Bible, thousands of years ago: "Three score and ten") before age-mediated stuff starts killing them. Not 60, not 80. And that is true of essentially all people we have numbers for, as far back as we can trace - Cro Magnons, say.

 

 

 

We live longer with lethal aging consequences due to modern medical care - but from about 70 on we are afflilcted with them. Medical care survival too is irrelevant to an assessment of our way of life before the natural lifespan - indicated by the onset of age-mediated mortality - kicks in.

 

 

 

Seriously? You're going to go creationist on me one paragraph after invoking "averages"?

 

As noted, there is no wide range in the onset of age-mediated mortality among the populations of human beings on this planet, now or as far back as we can track.

 

You yourself pointed out the selection for certain genetics that start killing people when they get old. If you put a number on "old", you'll find it's around 70, give or take.

 

Which, however informative, is somewhat tangential. The thread topic was about optimal human "habitat", which I took in a general sense encompassing diet etc.

 

 

The OP was rather specific about living in the original habitat that man evolved in. He even said he wants to go back to it and live there, harmonious with nature.

 

Where's the data? Give me some references that show the data saying that the average "old age" throughout human history has been 70. How do you even come up with such an average, as it seems entirely an arbitrary cutoff? Calculating average lifespan is very straightforward. Calculating average life span after the age of puberty is very strait forward. How do you then calculate the average life span for dying from old age in ancient man? That presumes to know a cause of death when for the majority of remains, you wont know the cause of death.

 

So I'm very skeptical of your claims and I am challenging you to show me the actual data. Show it to me and I'll admit you are right, but until then I remain skeptical. I am not discounting the grandmother hypothesis, I think it is likely right. What I am discounting is the idea that such a narrow age range is something that has been under strong selective pressure. It is you, after all, that has stated quite clearly that man has evolved to live into his 70s. I would argue that man has evolved to live longer yes, but that there is no strong selective pressure for how long he lives. The force Natural Selection declines rapidly past reproductive age. This was stated originally by Haldane and Medawar and formalized by Hamilton. Past reproductive age, one enters the "Selective Shadow" where deleterious alleles are hidden from the effect of Natural Selection. Diseases like alzheimers would be prime examples. Furthermore, genetic studies of human longevity suggest that it is a weakly heritable trait, and so it would be less responsive to natural selection acting on it. Finally, as work by Caspari has suggested, human longevity did not become common until recently, in the last 30,000 years and it appears to have been most likely the result of modernization and cultural changes.

Edited February 21, 2014 by chadn737

[Anopsology]

So are we kind of all just evolutionary mutts with specific adaptions to different areas of the world?

[CharonY]

I think it is missing the general point that being adapted to a certain habitat does not determine how you perform in another. Given a set of traits you may perform better worse or equal when put into different habitats. The assumption that once adapted to a certain situations you are at the maximum possible fitness is simply incorrect.

[chadn737]

I think it is missing the general point that being adapted to a certain habitat does not determine how you perform in another. Given a set of traits you may perform better worse or equal when put into different habitats. The assumption that once adapted to a certain situations you are at the maximum possible fitness is simply incorrect.

 

That is exactly what I have been trying to state, but said so much better.

[overtone]

 

 

The assumption that once adapted to a certain situations you are at the maximum possible fitness is simply incorrect.

 

That is exactly what I have been trying to state, but said so much better

So having gotten that out of the way, can we address the issues I raised in my posts - at least, in any post directly responding to mine?

 

 

 

The OP was rather specific about living in the original habitat that man evolved in

You haven't been quoting and responding to him, you've been quoting and responding to me.

 

 

 

Give me some references that show the data saying that the average "old age" throughout human history has been 70. How do you even come up with such an average, as it seems entirely an arbitrary cutoff? Calculating average lifespan is very straightforward. Calculating average life span after the age of puberty is very strait forward. How do you then calculate the average life span for dying from old age in ancient man? - -

I didn't, and one doesn't, normally calculate the average age of death. Instead, observe the age of observable onset of lethal age-related debility, wherever and whenever you can, and see if you see a pattern - in the case of Cro Magnons, for example, the common observation is that death before age 65 or so is generally by mishap, violence, or infectious disease, and the skeletons still have good teeth, sound musculature, good posture, recovery from past injury, etc. In the old Hebrew nomads, the good and suitable lifespan for the followers of God is 70. In the stone age cultures of NA the early Europeans found political councils of men and women in their 60s and early 70s, and that was the expected destination of those not killed in battle or mishap or infectious disease - the younger folk, men and women in their 50s say, were active and contributing hunters and warriors and gatherers and processors, not age-debilitated relics hanging around by charity.

 

And that (general good health into one's late 60s) would be one factor in one's attempted analysis via postulated optimal human environment - another possibly informative consideration would be average height. The average height of the men who stormed the Bastille in the French Revolution was around 62 inches - we can safely assume their environment was not optimal, and might easily acquire insight into what makes a better quality human environment by taking theirs as a bad one, and looking for what was wrong with it by comparing it with the environments of generally taller people.

 

 

 

Given a set of traits you may perform better worse or equal when put into different habitats.

Of course. But not by chance, eh? It depends on whether the adaptations you feature fit well in the new environment. One reasons from evidence, and a lot of the evidence is likely to come by way of consideration for the circumstances (and therefore the nature) of the earlier adaptation.

 

If you alter the environment to which an organism is adapted, put it in a different one, it would be a good idea to know what you are doing - what the old environoment and adaptations were, and how the new environment will fit. If you take the predators away, for example, you should pay attention to the new fit - it's not sensible to simply assume such a change is all to the good, without attending to the nature of the predator adaptations and how they will play out.

 

The example of sedentary living in an animal adapted to exercise was pointed out. There are others - zoos provide many. Removing orcas from the risks and tribulations of open ocean life, for one, decreases their life span and damages their health - consideration for the features of an optimal orca environment might provide insight. It would begin, normally, by careful analysis of the environment they are adapted to, and what the adaptations are. Is this controversial?

[Anopsology]

what about blue zones and longevity do you think living near the coast has something to do with living longer?

[arc]

yes I do believe that our skin tones have something to do with the envioronment we are best suited for.

 

Since a major major part of our evolution happened in the African Savanna does that mean it could be our current optimal habitat, or have we evolved past that?

or does ethnicity play a big role in where your natural habitat is?

 

I just always thought that the great apes our in the natural/optimal habitat right now so why shouldnt

there be a location best for us?

 

in my head there is this theory that there is specific location I should be in and be living in.. with the perfect temperature

and all natural food that my body is supposed to be eating, with the proper amount of sunshine, etc....

 

 

Or did us leaving Africa completely help humans evolve even more?

Is the African Savanna the same as it was in the days of our early ancestors.

 

The development of our large brain supplanted most all external physical adaptations, and in contrast to them, allowed, sometimes in mere minutes, adaptation through problem solving, what would have taken smaller brained hominids untold generations to physically adapt to if ever. A large brain is what is needed to adapt survival strategies.

 

It took a human size brain to create strategies and technologies to not only survive a short period, but to actually live and prosper in the arctic. We are now exploring the ocean and living in orbit around our planet. Could any hominid before us have done the same in such short time, through any other type of evolutionary adaptation?

 

Your ideal environment is actually right between your ears, but it is up to you to direct it to your fullest adaptive potential?