Climate and Human Development

[JohnB]

Firstly this is pure speculation, but I thought I'd chuck the idea out there and see what happens.

 

I'd very much appreciate comments from anyone with knowledge of Anthropology on this. I don't know what is said in the literature and haven't been able to find anything looking at this, but I could simply be looking in the wrong places, so input is welcome.

 

There is something about human societal development that I've always wondered about. H Sapiens evolved some 120,000 years ago (give or take). They are us, same brains, same intellect.

 

So how come they sat on their fat, hairy arses for 114,000 years before developing societies above "Hunter gatherer"? Why was all the development in the last 6,000 years?

 

The idea that most of the time was in an Ice Age doesn't cut it. Yes, there was a lot of ice, but large populated areas of the planet were quite fine for long term human habitation. Europe was iced over, but Africa was lush and fertile, so was Asia. Similarly the animals that became domesticated were available to those early humans in north Africa, so why the delay in domestication?

 

I think that the answer is constant climate change. To develop farming, animal husbandry and a stable society requires reasonably stable climatic conditions. You can't develop farming techniques if you have to move the farm every 3 generations or so. Development of farming techniques is a trial and error thing and you can only do this if most of the external factors (ie. Climate) remains reasonably constant.

 

When we think about the last 40,000 years, we tend to divide it into "Ice Age" and "Holocene". The Holocene being characterised by a warm and reasonably stable climate and the Ice Age as being "bloody cold", but we think of the ice age as constant too. Hence the quandary, if the Ice Age was reasonably constant, then farming etc should have developed much earlier in North Africa than it did. So why didn't it?

 

I invite you to look at this graph from Greenland covering the last 40,000 years.

 

 

Notice that most of the changes recorded by the ice in the Holocene are quite mild compared to general changes for the preceeding 30,000 years. (The current warming as we exit the Little Ice Age is that uptick on the very right of the graph.)

 

The large spikes in the 25-45,000 year range are known as Dansgaard–Oeschger events. Notice their size, 10-15 degrees in a century or less. There is arctic amplification involved here, but it is reasonable to assume changes in the lower latitudes of at least a degree or two. These are tremendous changes in short periods of time and indicate a very unstable global climate. Dansgaard–Oeschger events make the climate unstable.

 

Once we were into the Holocene and climate stabilised it took some 2,000 years to go from Hunter Gatherer to building cities. If we assume this time period to be reasonable for such development, then the lack of any stable 2,000 year period in the preceeding era precludes the development of stable farming communities and the later development of cities and towns.

 

So I submit that human development was not delayed by the "Ice Age" per se, but specifically by the highly unstable climate during that time caused by the Dansgaard–Oeschger events.

 

Thoughts?

[md65536]

There is something about human societal development that I've always wondered about. H Sapiens evolved some 120,000 years ago (give or take). They are us, same brains, same intellect.

 

So how come they sat on their fat, hairy arses for 114,000 years before developing societies above "Hunter gatherer"? Why was all the development in the last 6,000 years?

Perhaps knowledge is the key factor?

If you were raised by wolves and had no contact with humans, do you think you'd be planting and harvesting crops due to some instinctual knowledge? I don't.

 

Another aspect is our accelerated rate of development. As we develop we get better at figuring things out and at passing on knowledge of what we've figured out.

 

So perhaps the first hundred thousand years were not wasted sitting on our fat asses watching cave tv, but instead involved developing the prerequisite knowledge for graduating from "hunter gatherer". Developing language or communication skills, ability to use tools, building an understanding of plants, etc.

 

Certainly climate has an impact on development. As we've developed, we've also gotten better* at reducing the disruptive effects of climate (through the use of fire, shelter, etc) on our ability to survive and develop further.

 

 

* That is, until the modern era, I suppose...

 

 

 

Anyway, I think your hypothesis sounds reasonable and intriguing. However I don't agree that a relatively short period of relatively rapid development implies that similar development "should" happen in another period requiring only similar environmental conditions.

Edited August 17, 2011 by md65536

[pantheory]

JohnB,

 

The maps of Africa during the past and maybe prior ice ages, seem to indicate that there was no water for cultivation in the northern most half of Africa. Without water and rainfall, simple agriculture would not be possible. There seemed to be little habitable areas for humans during these times in northern Africa excepting for isolated areas and even these might have began to dry up forcing residents to escape by the easiest route which would have been moving east along the Mediterranean.

 

http://1.bp.blogspot...etation_map.png

 

During times of more rainfall man may have been able to travel greater distances, traveling through the middle east and settling in areas where water and game were more abundant. Until we domesticated plants like grain and fruit, we remained hunter gatherers. The first plows were probably made of wood or hand axes tied to wood, with one or two men pulling and one man controlling the plow. Before cultivation we existed in numbers like carnivores, such as lions. After we domesticated plants and animals we multiplied into numbers like gazelles

 

As you have suggested, more stable climates with increased rainfall, and melting glaciers, probably provided the water needed for man to flourish out of Africa.

Edited August 18, 2011 by pantheory

[md65536]

So perhaps the first hundred thousand years were not wasted sitting on our fat asses watching cave tv, but instead involved developing the prerequisite knowledge for graduating from "hunter gatherer". Developing language or communication skills, ability to use tools, building an understanding of plants, etc.

Actually I must retract this proposition. I don't think that the development of knowledge could be passed down for say 5000 generations, and grow in a steady, stable way. It must have developed in a sort of punctuated equilibrium, with a lot of dead ends and lost knowledge. I still don't think there needs to be some effect that prevented the development of some specific technology in a timely way (for example, is there some force holding us back from developing the things that we've never imagined yet? Will future generations wonder why we didn't just do it?). But climate change definitely sounds like it would have a disruptive effect on development and hold back agriculture.

[JohnB]

Sorry for the delay, I've been inspecting the Queensland hospital system from the inside.

 

Thank you both for the replies, at least now I know the idea doesn't seem crazy.

 

md65536.

 

I agree actually that knowledge is key factor. The thing is that knowledge can only increase rapidly if there is a segment of the population who are free to think rather than spend their time in finding food. A hunter gatherer society is very labour intensive and people spend more time looking for food that actually thinking about better ways to get food. Consider the effect of domestication on food supply. In a HG society the men would go out and spend a day or days trying to find the food, then they had to kill it and then transport it back to the tribe. You could be talking about having 10 men occupied for 4 days just to get the meat from one cow. Once you have domesticated animals, it's a simple matter for 2 men to get a cow from "that pen over there", kill it and provide the meat. This frees up a lot of time and allows knowledge to grow.

 

Aside: It wouldn't surprise me if the first "domestication" came from finding a herd in a sheltered valley and some bright spark saying "You know, if we build a wall across the valley mouth, they can't get out and we will know where to find them next time." Shortly after that the tribe moved closer to the valley and became more stationary.

 

Similarly HG societies tend to move around a lot because the prey animals start to avoid the areas the tribesmen hunt in. They move to follow the herds, if the herds stop moving, so do they.

 

pantheory.

 

Totally agree about north Africa, but who said it had to start there? Humans had spread all the way to Australia by 40,000 years ago. There was forest and savannah across southern Europe and east of the Med all the way to India. All the animals that were later domesticated were available to the early humans, all the plant species that were domesticated were also available, so the question was "Why the delay?" All the tools, plants and animals were there, why weren't they used? There is no obvious reason why the fertile cresent was (or had to be) the region where agriculture started.

 

What I'm suggesting is a mechanism and explanation of why it was the fertile crescent. Consider my aside above. During the Ice Age due to the rather wild swings climate went through, that walled off valley would have become quickly too wet or too dry for holding cattle (too dry and the grass runs out, too wet and foot rot sets in), the tribe would have had to move and the process restarted elsewhere. I'm suggesting that the climate was simply too variable for extended stays in any given area. The fertile areas kept moving.

 

The reason that agriculture flourished in the fertile crescent was that that was the "fertile area" when the climate stabilised. If the climate had stabilised at a slightly higher temp, then the "fertile Crescent" might have been on what are now the Mongolian grasslands, if a bit cooler, then perhaps India or subtropical Africa.

 

The argument is based on the premise that knowledge can't grow without leisure time away from survival and that this time can only become available once domestication of plants and animals is achieved. Domestication takes time in a stable climate and since the Ice Age was decidedly unstable domestication could not occur. Hence it was not the Ice Age per se that prevented development, but the wild swings during that Ice Age that did.

 

To put it another way, if the Ice Age had had a stable (but much colder) climate than now, domestication and civilisation would have risen much earlier and in a totally different place.

 

(This is actually starting to bug me. I guess I'll have to add Anthro texts to my reading list now. )