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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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By wgbutler on 1/2/2013 6:45:14 PM , Rating: 2

In my view, atheism and theism share similar logical fallacies. We cannot conclusively prove either one is true.

True. But you can look at the claims of both and see which has the best explanatory power given the reality that we live in.

Atheism claims that everything came from nothing, that all the fine tuning of the Universe and design of biology is due to blind chance, life came from non-life, and consciousness came from non-consciousness. I think these claims have about as much credibility as religions that say that the world was hatched out of a giant egg.

Theism, on the other hand, states that a powerful Intelligence created and designed the universe, and life, which fits all of the data that we are able to scientifically ascertain since we know that the Universe has not always been here, that it is fine tuned, and we have no way to create life from scratch out of non-living components. Between the two hypothesis, theism has far greater explanatory power.

I guess you could say that other options could be true (i.e. we are really in a computer simulation) but philosophically you still have to deal with the issue of origins and morality.


The account of creation as given in the Bible is another matter - thats pretty much been blown out of the water.

Actually, the account of creation is quite remarkable, especially given that it was written thousands of years ago in a world dominated by pagan beliefs. Think about it for a minute:

1) It claims that the Universe had a beginning, something even scientists did not finally believe until the twentieth century.
2) It claims that the sun, moon, earth, and stars are not divine beings that should be worshiped but are simply created objects - quite a heretical claim given the time that it was written!
3) It claims that light was the first distinct thing in existence, which we know to be true as light first came out of matter 380,000 years after the big bang.
4) It outlines a general history of life on Earth, culminating with the appearance of mammals and finally mankind, something the fossil record validates.

Regarding the days and creation week, this is easily explained that the timeframes being used are from God's point of view, which is really the only logical explanation as the sun didn't even exist until the 4th day of creation. And we know that time is relative and passes differently depending on where you are in the Universe. Why would it be so hard to think that what passes for a day in the realm of an eternal Being would be billions of years for someone standing on Earth?

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