Study: Human Evolution Forced by Chaotic Landscape
December 27, 2012 1:45 PM
comment(s) - last by
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
and her graduate student, Clayton Magill, have put forth an intriguing study, which suggests that chaos in the ecosystem of East Africa drove
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
the researchers traveled to the
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.
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."
The papers suggest chaotic climate changes triggered the rise of human intelligence.
[Image Source: Pace J. Miller]
The research was published as a
[abstracts] in the prestigious peer-reviewed journal
The Proceedings of the National Academy of Sciences
). Among the other researchers working on the team was
earth and planetary sciences professor
. The research was funded by a
National Science Foundation
This article is over a month old, voting and posting comments is disabled
12/28/2012 3:08:53 PM
Sure, men that evolved from apes would surely explain how they are so blindly accepting of a blatantly false evolutionary system that has been proven as a false theory. Yet some still cling to the notion due their own poor education that evolution is a fact and law of nature, not just a theory.
Otherwise labs would have been able to mix non-life containing elements to create single celled life forms. Or keep rats in a "cold climate" tank for dozens of generations and seen evolution take place over a few dozen generations to include thicker fur, higher resistance to cold, etc, yet they have not, they do not "evolve", they simply stay the same, using the genes and traits they have to survive instead of evolving into wooly fluffy rats.
Every "study" done cannot place direct links between ape and man (outside of obvious and know similarities), so therefore is still an unproven theory.
12/28/2012 4:00:25 PM
Evolution is real, get over it.
“We do believe we have a moral responsibility to keep porn off the iPhone.” -- Steve Jobs
Study: Upright Hominid Posture Evolved Far Earlier Than Previously Thought
July 20, 2011, 4:30 PM
Study: How Human Evolution Caused us to Lose Our Spiny Penises
March 10, 2011, 9:30 AM
Fifty-Five Million Year Old Horse Teeth Reveal Evolution Lags Behind Diet
March 5, 2011, 1:43 PM
Study Defends That "Darwin" Species From 47 MYA Was Human Ancestor
October 12, 2010, 2:10 PM
Star Wars Spinoff Film "Rogue One", Theme Park Attractions Announced
August 17, 2015, 12:20 PM
SpaceX Falcon 9's Seventh Supply Mission to ISS Ends w/ Fiery Stage 1 Explosion
June 28, 2015, 1:10 PM
Cool Science Video: Glowing Millipede Prowls the Nevada Desert
May 18, 2015, 12:00 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Researchers Hope to Find "Exotic" Lifeforms Inside Crater of Dinosaur Killing Meteor
April 14, 2015, 8:47 PM
Mathematician's Sociological Formulation May Explain the "Hipster Paradox"
April 14, 2015, 1:13 PM
Most Popular Articles
Microsoft Band 2 Stays Focused on Fitness, Debuts Oct. 30, Priced at $249
October 6, 2015, 9:16 PM
Microsoft's HD-500 ("Display Dock"), the Magic Sauce Behind Continuum
October 6, 2015, 5:30 PM
Microsoft Lumia 950 and 950 XL Finally Launch, w/ Windows 10, Liquid Cooling
October 6, 2015, 3:35 PM
Legere Blasts Microsoft for "Bull***t" Snub of T-Mobile and Verizon
October 9, 2015, 3:02 PM
Apple's First Fixes to iOS 9 Land w/ iOS 9.0.1 Release
September 23, 2015, 6:11 PM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2015 DailyTech LLC. -
Terms, Conditions & Privacy Information