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Adversity breeds strength -- and perhaps human intelligence

It's a widely held hypothesis that ecological and climatological changes had a crucial driving role in evolution throughout history.  Now Penn State University geoscience professor Katherine Freeman and her graduate student, Clayton Magill, have put forth an intriguing study, which suggests that chaos in the ecosystem of East Africa drove mankind's ancestors to radically evolve 2 million years ago.

I. Life on the Chaotic Savanna

Mr. Magill comments, "The landscape early humans were inhabiting transitioned rapidly back and forth between a closed woodland and an open grassland about five to six times during a period of 200,000 years.  These changes happened very abruptly, with each transition occurring over hundreds to just a few thousand years."

To examine the ecological transition that coincided with this crucial phase of hominid evolution the researchers traveled to the Olduvai Gorge in northern Tanzania, collecting lake sediments.  Filtering the sediments of different ages, they performed biochemical analysis looking for fossilized chemical traces of grasses and trees.

Specifically, they sifted through sediments looking for leaf waxes, hardy biochemicals that tend to resist breakdown and survive, even over millions of years.  By performing gas chromatography and mass spectrometry analyses on the various waxes, the researchers were able to pinpoint both the foliage and composition to within a couple centuries.

Tanzania Gorge
Biochemical analysis of local sediments in a Tanzania gorge have offered key clues as to the evolutionary path of mankind's hominid ancestors. [Image Source: Gail Ashley]

What they discovered was that the "Great Drying", which is widely proven to have occurred in Africa around 3 million years ago, was not as much of a one-way process as was previously thought.  Rather, the sediments showed that the local ecosystem appears to have gone through a chaotic transition period in which the climate would fluctuate between wet and dry, before eventually gravitating fully to drier savanna.

To better understand the source of such strange and chaotic cycling, the researchers used statistical and mathematical models to formulate a hypothesis on the causes.  

Explains Professor Freeman, "The orbit of the Earth around the sun slowly changes with time.  These changes were tied to the local climate at Olduvai Gorge through changes in the monsoon system in Africa. Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation."

"We found a correlation between changes in the environment and planetary movement.  We find complementary forcing mechanisms: one is the way Earth orbits, and the other is variation in ocean temperatures surrounding Africa."

II. Adversity Breeds Evolved Intelligence

The chaos would obviously cause great stress on hominids living in the region forcing them to adapt to different food sources, different landscape, and different predators.  Mr. Magill and Professor Freeman suggest this was a key driver of the evolution of human intelligence.

Comments Mr. Magill, "Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response.  Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes." 

"The result can be increased brain size and cognition, changes in locomotion and even social changes -- how you interact with others in a group. Our data are consistent with these hypotheses. We show that the environment changed dramatically over a short time, and this variability coincides with an important period in our human evolution when the genus Homo was first established and when there was first evidence of tool use."

human intelligence
The papers suggest chaotic climate changes triggered the rise of human intelligence.
[Image Source: Pace J. Miller]

The research was published as a pair of papers [abstracts] in the prestigious peer-reviewed journal The Proceedings of the National Academy of Sciences (PNAS).  Among the other researchers working on the team was Rutgers University earth and planetary sciences professor Gail Ashley.  The research was funded by a National Science Foundation (NSF) grant.

Sources: PNAS [1], [2]



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RE: more propaganda
By retrospooty on 12/28/2012 4:34:49 PM , Rating: 2
Ancient Aliens? Alot of interesting stuff on that show. Some of its a bit crazy, but alot of it really makes you think.


RE: more propaganda
By Cheesew1z69 on 12/28/2012 4:45:54 PM , Rating: 2
It sure does, and kind of makes some sense. The "aliens" or "god" has "programmed" us.

And they think they still do, buy "uploading" new "data" to us to constantly tweak us.


RE: more propaganda
By retrospooty on 12/28/2012 4:53:36 PM , Rating: 2
Tsoukalos hair really makes you think LOL

http://memeimages.com/people/ancient-aliens-guy-gi...


RE: more propaganda
By Cheesew1z69 on 12/28/2012 5:01:05 PM , Rating: 1
No shit! That is one crazy lookin dude! :D


RE: more propaganda
By TakinYourPoints on 12/30/2012 5:57:22 AM , Rating: 2
Yeah, makes you think "wow, this is really stupid". ;)

The only ancient aliens that we are probably evolved from are microbes that hitchhiked on a comet that impacted the Earth and seeded life here. Problem is that the theory that life came from homegrown activity on Earth is probably just as (or more) likely, but we don't know for certain, so whatever. We evolved from those humble beginnings in either case.

Intelligent design by a deity or aliens though, both the same nonsense IMHO.


RE: more propaganda
By Piiman on 12/31/2012 4:35:35 PM , Rating: 2
"Some of its a bit crazy"

Yeah like that one guys hair! LOL
I also love how no matter what the subject they always say "Ancient Alien Theorist believe." LOl Just who are these Ancient Alien Theorist and could they be Ancient Alien themself? Something to think about:-)

Hey for all the God people maybe God is just an Alien or the planet earth is just an Alien Zoo and God is the zoo keeper.


"The whole principle [of censorship] is wrong. It's like demanding that grown men live on skim milk because the baby can't have steak." -- Robert Heinlein














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