Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Early Americans faced rapid late Pleistocene climate change and chaotic environments

20.02.2006


The environment encountered when the first people emigrated into the New World was variable and ever-changing, according to a Penn State geologist.



"The New World was not a nice quiet place when humans came," says Dr. Russell Graham, associate professor of geology and director of the Earth & Mineral Sciences Museum.

Archaeologists agree that by 11,000 years ago, people were spread across North and South America, but evidence is building for an earlier entry into the New World, a date that would put human population of North and South America firmly in the Pleistocene.


"We want to know what it was like back then," says Graham. "What did they have to deal with?"

The Pleistocene Holocene transition took place about 11,000 years ago and caused the extinction of a large number of animal species including mammoths, mastodons and ground sloths. The Holocene looked very different from the Pleistocene.

"We now realize that climate changes extremely rapidly," Graham told attendees at the annual meeting of the American Association for the Advancement of Science today (Feb.19) in St. Louis, Mo. "The Pleistocene to Holocene transition occurred in about 40 years."

As a result, animals and plants shifted around and the people living in the New World had to adapt so that they could find the necessary resources to survive. Graham likened the change to the difference between shopping at a WalMart where there is great abundance and large variety – the Pleistocene – to suddenly having to shop at a corner convenience store – the Holocene. In human terms this means that what grandparents knew to be true about finding resources, could be untrue and not helpful to grandchildren.

During the Pleistocene large eastern coastal resources existed, including walruses, south, as far as Virginia, seals and a variety of fish. Mammoth, caribou and mastodons were plentiful across the continent as well as smaller animals. The situation was not identical in all places across North America because, during segments of the Pleistocene, large portions of the Eastern North American continent were covered in ice, while western locations were ice free much further north.

"The Holocene climate is much more stable than the Pleistocene – warmer but more stable," says Graham. "The environment, however, became more homogeneous, there was less variety."

Graham argues that the Pleistocene experienced a series of rapid climate changes that created patchiness in the environment, but that once the climate change that signaled the beginning of the Holocene occurred, the climate settled down. Humans coming into the New World during the late Pleistocene would have encountered an environment shaped by rapid changes creating variety in available food sources both animal and vegetable. The groups of people would have to adapt continually and find new resources, but the variety of resources was out there. After the Holocene took hold, there was less need to adapt constantly, but also fewer options in resources.

Archaeologists and geologists debate whether the climate change at the Pleistocene Holocene transition caused the extinction of the mega fauna or if the influx of humans did in the large animals. Graham believes that it was the unstable changing rapidly changing climate, not human predation that killed the large Pleistocene animals.

A’ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Earth Sciences:

nachricht For a rare prairie orchid, science is making climate change local
12.02.2016 | USDA Forest Service - Northern Research Station

nachricht NASA sees Tropical Cyclone Winston form
12.02.2016 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Production of an AIDS vaccine in algae

Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.

The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Symposium on Climate Change Adaptation in Africa 2016

12.02.2016 | Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

 
Latest News

LIGO confirms RIT's breakthrough prediction of gravitational waves

12.02.2016 | Physics and Astronomy

Gene switch may repair DNA and prevent cancer

12.02.2016 | Life Sciences

Using 'Pacemakers' in spinal cord injuries

12.02.2016 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>