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 Underground fungi detected from space
04.05.2016 | Smithsonian Tropical Research Institute

nachricht How much does groundwater contribute to sea level rise?
03.05.2016 | International Institute for Applied Systems Analysis (IIASA)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nuclear Pores Captured on Film

Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.

Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...

Im Focus: 2+1 is Not Always 3 - In the microworld unity is not always strength

If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”

In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...

Im Focus: Tiny microbots that can clean up water

Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.

Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

New fabrication and thermo-optical tuning of whispering gallery microlasers

04.05.2016 | Physics and Astronomy

Introducing the disposable laser

04.05.2016 | Physics and Astronomy

A new vortex identification method for 3-D complex flow

04.05.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>