Do big brains stem from cooler climates?
Big brains need cool climates to evolve and do their job well, according to new research published in the journal Climatic Change.
If you've been wondering who to thank for your extraordinarily large brain thank the Earth's last 50 million years of chilly weather, says David Schwartzman, a biology professor at Howard University and chief author of the report.
Without it, our savannah-savvy, tool-wielding ancestors Homo habilis and Homo erectus might not have emerged, the study claims. Why? Because big brains generate a lot of heat, and we get rid of heat much more easily when the climate's cool.
It's not hard to see where this is going. Burning fossil fuels and warming up the planet will make it harder for our struggling brains to cool down, says Dr Axel Kleidon at the University of Maryland.
'An important implication', Dr Kleidon concludes, 'is that global warming is likely to lead to environmental conditions less suitable for human metabolic activity in their natural environment ... due to a lower ability to loose heat.'
(Confused? The Kinks' song, 'Apeman', sums up Kleidon's concerns admirably.)
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It makes a lot of sense. Does this mean global warming will make us stupid? ;P
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Obviously all the Global Warming/Al Gore/Green aficionados have tiny, shriveled brains.
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Who knows. Scientists seem to be at a loss deciding whether bigger brains = more intelligent or whether a spot of DIY neural reorganisation and 'connectional modification' will do the job.
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Have Drs. Schwartzman and Kleidon considered the explosive racial implications of their theory? Thank god they have all those ancient Swedish and Inuit civilizations to back them up.
I guess this explains the failure of warmer climes like Egypt, the Middle East and Southern Europe to establish their own cultures.
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Well, Globalclaptrap proves the opposite: as temperatures rise, the intelligence decreases...
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There are many hypotheses as to why human brain size increased (but it's still not as large as, say, those of elephants).
Language development, evolving from sociability and co-operation in hunting, food gathering and child-rearing is a forerunner.
Another (and similar) is it comes from the stimulus of surviving as groups in a savannah environment, where both finding food and evading predators was challenging. Another (similar) hypothesis has climate change (or rather consequent environment changes) as an explanation for hominids migrating out of Africa; wetter conditions meant savannah spread from Africa into central Asia, dryer conditions meant a return of a dry Sahara which forms a natural barrier. (The Sahara has been wet and dry in erratic long term episodes.)
The so called Savannahstan hypothesis. Survival, and need for co-operation along the away, helped develop cognitive functions.
This is controversial, but the discovery of older and older hominid remains in Asia are challenging the idea that modern hominids migrated fully formed out from Africa.
http://sinanthropus.blogspot.com/2006/07/problems-with-out-of-savannahstan.html
Survival in cold environments does require great ingenuity. Often overlooked and under-rated are those peoples that lived (and still live) in polar and sub-polar environments; often still relying on highly sophisticated 'stone age' technologies that modern materials and methods still struggle to match.
But as a sole reason for hominid brain size increase, I doubt it. The development of communication and language is a more compelling reason.
I think hominids could only have managed to adapt to such cold environments after developing language, sophisticated tool use and domesticating animals. (Dogs, reindeer etc)
There is also determinism in Keidon's hypothesis (some would say its racist). So, any European born and brought up in a tropical country will be less intelligent than one born and raised in a sub polar country?
If looking for explanations as to why, say, Africa is less developed than other regions? then look to the Sahara.
The Egyptians nor Romans never conquered the Sahara; it formed a natural barrier to the spread of ideas and technology. (The Arabs and Europeans only reached it after developing sea-going vessels capable of reaching its coasts.)
North Africa's development followed a very different path from the regions south of the Sahara. (You may have noticed that Egypt is also quite hot.)
Much of China on the other hand (the Chinese can't be said to have been backward in the civilisation stakes) is in tropical or sub-tropical zones, and there was an exchange of ideas and technology between the Mediterranean region and China, via the silk roads, stretching back thousands of years.
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Dear Shanta, once again, delightful.
But, perhaps our brains grew in size because we used them. Just like your arms - if you work out in the gymn, they grow - if you don't use them, they turn to flab and deteriorate. That does not bode well for future growth in brain size...
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