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
RE: more propaganda
12/28/2012 3:02:56 PM
Regarding Santa: An Engineers Perspective
I. There are approximately two billion children (persons under 18) in the world. However, since Santa does not visit children of Muslim, Hindu, Jewish or Buddhist religions, this reduces the workload for Christmas night to 15% of the total, or 378 million (according to the Population Reference Bureau) At an average (census) rate of 3.5 children per house hold, that comes to 108 million homes, presuming that there is at least one good child in each.
II. Santa has about 31 hours of Christmas to work with, thanks to the different time zones and the rotation of the earth, assuming he travels east to west (which seems logical). This works out to 967.7 visits per second. This is to say that for each Christian household with a good child, Santa has around 1/1000th of a second to park the sleigh, hop out, jump down the chimney, fill the stockings, distribute the remaining presents under the tree, eat whatever snacks have been left for him, get back up the chimney, jump into the sleigh and get on to the next house.
Assuming that each of these 108 million stops is evenly distributed around the earth (which, of course, we know to be false, but will accept for the purposes of our calculations), we are now talking about 0.78 miles per household; a total trip of 75.5 million miles, not counting bathroom stops or breaks. This means Santa's sleigh is moving at 650 miles per second --- 3,000 times the speed of sound. For purposes of comparison, the fastest man-made vehicle, the Ulysses space probe, moves at a poky 27.4 miles per second, and a conventional reindeer can run (at best) 15 miles per hour.
III. The payload of the sleigh adds another interesting element. Assuming that each child gets nothing more than a medium sized Lego set (two pounds), the sleigh is carrying over 500 thousand tons, not counting Santa himself. On land, a conventional reindeer can pull no more than 300 pounds. Even granting that the "flying" reindeer could pull ten times the normal amount, the job can't be done with eight or even nine of them--- Santa would need 360,000 of them. This increases the payload, not counting the weight of the sleigh, another 54,000 tons, or roughly seven times the weight of the Queen Elizabeth (the ship, not the monarch).
IV. 600,000 tons traveling at 650 miles per second creates enormous air resistance --- this would heat up the reindeer in the same fashion as a spacecraft re-entering the earth's atmosphere. The lead pair of reindeer would absorb 14.3 quintillion joules of energy per second each. In short, they would burst into flames almost instantaneously, exposing the reindeer behind them and creating deafening sonic booms in their wake.
The entire reindeer team would be vaporized within 4.26 thousandths of a second, or right about the time Santa reached the fifth house on his trip.
Not that it matters, however, since Santa, as a result of accellerating from a dead stop to 650 m.p.s. in .001 seconds, would be subjected to centrifugal forces of 17,500 g's. A 250 pound Santa (which seems ludicrously slim) would be pinned to the back of the sleigh by 4,315,015 pounds of force, instantly crushing his bones and organs and reducing him to a quivering blob of pink goo.
Therefore, if Santa did exist, he's dead now. "
If you think the math behind Santa is funny, you might want to look at the math behind evolution. It is literally a million orders of magnitude worse...quit being a religous racist.
RE: more propaganda
12/28/2012 3:12:26 PM
Lets not forget Santa is FAT and fat people aren't exactly known for their athletic speed and agility.
RE: more propaganda
12/28/2012 4:19:27 PM
quit being a religous racist
Quit being a close minded moron.
RE: more propaganda
12/31/2012 4:44:57 PM
Santa is no more real than God. At leat no one has started a War because Santa told them to kill everyone that didn't believe in him. Stop being a Santa racist!
"What would I do? I'd shut it down and give the money back to the shareholders." -- Michael Dell, after being asked what to do with Apple Computer in 1997
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
Nail Polish May Soon be Able to Detect Date Rape Drugs
August 26, 2014, 7:57 AM
SpaceX Falcon 9-R Rocket Suffers Malfunction, Self-Destructs During Test Flight
August 23, 2014, 9:36 AM
Texas Chosen as Site for SpaceX's First Commercial Launchpad
August 5, 2014, 1:44 PM
South Carolina Prison Finds Crashed Drone Carrying Drugs, Phones
August 1, 2014, 2:49 PM
NASA's Mars 2020 Rover Gains Seven New Instruments for Exploration
August 1, 2014, 1:30 PM
NASA Opportunity Rover Breaks Record for Most Miles Traveled on Another Planet
July 29, 2014, 1:38 PM
Most Popular Articles
Dell Announces "World's Thinnest" Tablet: The Venue 8 7000 Series
September 11, 2014, 8:51 AM
Apple Announces Its Smartwatch: The $349 Apple Watch
September 9, 2014, 2:09 PM
Quick Note: Buy an Xbox One Sept 7-13, Get a Free Game
September 4, 2014, 10:42 AM
Quick Note: Microsoft to Ditch Windows Phone, Nokia Branding
September 10, 2014, 2:14 PM
Apple Announces 4.7" iPhone 6, 5.5" iPhone 6 Plus
September 9, 2014, 1:45 PM
Latest Blog Posts
Space Terrorism is a Looming Threat For the United States
Apr 23, 2014, 7:47 PM
Facebook Aims to Provide Internet to "Every Person in the World" with Drones, Satellites
Apr 1, 2014, 10:20 AM
Retail Mobile Sites Experience Outages in Light of Simplexity's Bankruptcy
Mar 14, 2014, 8:48 AM
Tesla vs. BMW: Who Has the Safer EV?
Feb 1, 2014, 2:56 PM
Justice Leaks Details of Next HTC One Two Flagship Phone
Dec 5, 2013, 4:04 PM
More Blog Posts
Copyright 2014 DailyTech LLC. -
Terms, Conditions & Privacy Information