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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 12/27/2012 7:07:51 PM , Rating: 2
Don't start up again. You have already been outed as a complete waste of skin in the last evolution article. The debate is over, evolution happened... If you cant accept facts and move on them just STFU and keep your elementary view of life to yourself.


RE: more propaganda
By heerohawwah on 12/28/12, Rating: 0
RE: more propaganda
By retrospooty on 12/28/2012 3:54:13 PM , Rating: 2
"retrospooty, I seem to remember you making a rather racist comment last time too; a very short sighted science about black people evolving from white people...a mutation as you claimed."

Racist? Are you smoking crack? I didn't say Black people evolved from white people. I said we are all the same people. White people's skin is light because as they left
Africa and migrated into Europe and their skin lightened. The UV rays of the sun kill vitamin D and melonin regulates it. That isnt racism, that is the opposite. It is showing that we are all of the same species and our differences are weather related, and nothing else. It also isn't a mental problem its proven science. http://www.livescience.com/7863-people-white.html


"The fact that no one has given me a single answer proves that well enough. "


Just becasue you arent cant grasp it, doesnt mean it hasnt been given to you. As I said before it's been proven many times over . Its not even a debate anymore. Its been proven in the 100's of thousands of fossils found all over the earth, documenting every step of the way from a chimp like ape to modern human EVERY STEP OF THE WAY. Its been proven in our DNA, its been proven via geological evidence as well as archaeological evidence. It has also been witnessed as strains of germs develop resistances antibiotics. It is also proven in human skin color. There is no debate that evolution happened. We may not know how it started, and/or who started it or possibly created the laws of the universe that enabled it but we know it happened.

If you want to have a religious debate, it can be said that a god or whatever created the universe and the laws of physics that allowed evolution to happen. You could even debate that a god created evolution with humans in mind as the end result, but you CANNOT say that evolution didn't happen... It is absolutely 100% proven. IF you think it isnt you need to go back to school, because your bible college has lied to you and given you false talking points to try and discredit proven science.


RE: more propaganda
By Cheesew1z69 on 12/28/2012 4:13:33 PM , Rating: 2
I actually watched a program recently that was talking about aliens as who may have created us due to the portrayal of ancient civilization giving clues to un-earthly beings coming down from the sky.

It was a very interesting show.


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.


RE: more propaganda
By drycrust3 on 12/29/2012 4:42:12 AM , Rating: 1
quote:
but you CANNOT say that evolution didn't happen... It is absolutely 100% proven.

No, The theory of Evolution is still an unproven theory. It isn't even close to being a credible theory, and every day it gets further and further from the truth. Notice that? It's taking you in the wrong direction! A good theory, which the theory of Evolution isn't a good example of, can be used to make predictions.


RE: more propaganda
By retrospooty on 12/29/2012 7:40:53 AM , Rating: 2
You are wrong. Like i said, we don't know all the details on how it happened, what started it, or why, but we do know that it happened. There are mountains of evidence proving it did happen. We came from Apes that came from earlier primates that came from reptiles that came from the sea etc etc.


RE: more propaganda
By TakinYourPoints on 12/30/2012 6:00:23 AM , Rating: 2
Natural selection has been proven for well over a century. It has absolutely been proven and only gains strength as time goes on.

Holy crap, I didn't know the types of idiotic discussions I've had on DT could range so far and wide. People really still deny this?


RE: more propaganda
By retrospooty on 12/30/2012 10:30:18 AM , Rating: 2
I know. It amazes me that some people are still debating this. They may as well be arguing that the world is flat and that the sun travels across its sky every day. Scary... Just scary.


"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -- Isaac Asimov














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