Piperno, Laguna Tuxpan, Iguala Valley
Caption: Cores from Laguna Tuxpan in Mexico's Iguala Valley, provided evidence for maize and squash cultivation along its edges by ~8000 B.P. and for the major dry event between 1800 and 900 B.P.
Posted on 06/02/2007 1:52:29 PM PDT by blam
Contact: Dolores Piperno
pipernod@si.edu
202-633-1912
Smithsonian Tropical Research Institute
Smithsonian scientists connect climate change, origins of agriculture in Mexico
Cores from Laguna Tuxpan in Mexico's Iguala Valley, provided evidence for maize and squash cultivation along its edges by ~8000 B.P. and for the major dry event between 1800 and...
New charcoal and plant microfossil evidence from Mexico’s Central Balsas valley links a pivotal cultural shift, crop domestication in the New World, to local and regional environmental history. Agriculture in the Balsas valley originated and diversified during the warm, wet, postglacial period following the much cooler and drier climate in the final phases of the last ice age. A significant dry period appears to have occurred at the same time as the major dry episode associated with the collapse of Mayan civilization, Smithsonian researchers and colleagues report in the Proceedings of the National Academy of Sciences online.
“Our climate and vegetation studies reveal the ecological settings in which people domesticated plants in southwestern Mexico. They also emphasize the long-term effects of agriculture on the environment,” said Dolores Piperno, curator of archaeobotany and South American archaeology at the Smithsonian’s National Museum of Natural History and the Smithsonian Tropical Research Institute in Panama.
Piperno’s co-authors include Enrique Moreno and Irene Holst, research assistants at STRI; Jose Iriarte, lecturer in archaeology at the University of Exeter in England; Matthew Lachinet, assistant professor at the University of Nevada in Las Vegas; John Jones, assistant professor at Washington State University; Anthony Ranere, professor at Temple University; and Ron Castanzo, research collaborator at the National Museum of Natural History.
Pollen of Podocarpus, a conifer now found primarily at higher elevations, is common in the oldest strata of sediment cores taken from lakes and a swamp in the central Balsas watershed. Along with pollen from grasses and other dryland plants, the Podocarpus indicates the environment encountered by humans at the end of the last ice age (14,000-10,000 B.P.) was drier and 4 or 5 degrees Centigrade cooler than it is today.
The Balsas valley is one of the most likely sites for the domestication of corn (Zea mays) from its wild ancestor, teosinte (Zea mays ssp. parviglumis) because populations of modern teosinte from that region are genetically closest to maize. As the lakes formed beginning around 10,000 B.P., they became magnets for human populations who exploited the fertile soils and rich aquatic resources the lakes contained. The researchers found prehistoric pottery sherds and other artifacts in sediments at the edges of the lakes. At one lake, phytolith data shows that maize and squash were probably planted at the fertile edges by 8000 B.P. Pollen from teosinte is indistinguishable from that of maize, but Zea pollen is consistently present in the cores since the end of the last ice age.
Pollen and phytoliths from weeds associated with crop plants become plentiful in the cores at roughly 6300 B.P Charcoal associated with agricultural burning practices also is abundant at that time. Between 1800 B.P. and 900 B.P., a major drying event occurred, corresponding to the time when a drought occurred in the region of the Classic Mayan civilization. This evidence shows that even during the Holocene, severe, short-term climatic oscillations occurred that may have had considerable importance for social change.
“We continue to find that tropical forests played a much more important role in the origin of agriculture in the New World than was once thought,” Piperno said.
Piperno, Laguna Tuxpan, Iguala Valley
Caption: Cores from Laguna Tuxpan in Mexico's Iguala Valley, provided evidence for maize and squash cultivation along its edges by ~8000 B.P. and for the major dry event between 1800 and 900 B.P.
Wrong-O!
Climate is static.
Al Gore says so.
It's settled, DAMMIT!
Please FREEPMAIL me if you want on or off the
"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
Gods, Graves, Glyphs (alpha order)
Unless the Incas had SUV's.
The climate always is changing. We only have to recall that the vast, flat lake bed that Edwards Air Force Base is famous for was formed some 10,000 years ago as the glacier retreated.
The quaint cliff dwellings so popular with tourists in the American southwest were abandoned about 1000 years ago because the climate in the entire region became so dry that farming was no longer possible.
Then there is the case of it becoming warm enough in the north Atlantic Ocean for Erik the Red to settle the island named *Greenland* which at the time sported a climate that supported row crops and raising of cattle.
The question before us now is not one of climate change, but more complicated: to what extent have humans caused harmful climate change, and to what extent can humans mitigate that change.
Sadly, people with various agendas cannot resist the temptation to use the solid science behind climate change to imply that equals human caused climate change. This is simply a Big Lie, which by now has been repeated enough that some useful idiots are beginning to believe it.
You are making the mistake that what the Icelandic sagas refer to as farms are similar to farms in your area. The farms on Greenland raised mostly cattle, sheep and hay, suffered from over grazing rather quickly and I believe that the only row crops that would have been raised would have been things like cruciferious vegetables.
Hmmm. I read a report about a sudden drop in the number of Cat-5 hurricanes in the Gulf Of Mexico about 1,100 years ago. May be related?
What does B.P. mean? I'm familiar with the new secular time designation, B.C.E., but I've never heard of B.P.
My focus was on a climate that, at the time, was sufficiently warm to support crops, which serves to demonstrate that climate does change by itself in material ways, and later, as was demonstrated in 1816 with weather that was so cold in the Northern Hemisphere, it was known as the Year Without A Summer:
from:
http://en.wikipedia.org/wiki/Year_Without_a_Summer
>>
In May of 1816[4], however, frost killed off most of the crops that had been planted, and in June two large snowstorms in eastern Canada and New England resulted in many human deaths. Nearly a foot of snow was observed in Quebec City in early June. In July and August, lake and river ice were observed as far south as Pennsylvania. Rapid, dramatic temperature swings were common, with temperatures sometimes reverting from normal or above-normal summer temperatures as high as 95 °F (35 °C) to near-freezing within hours. Even though farmers south of New England did succeed in bringing some crops to maturity, maize (corn) and other grain prices rose dramatically. Oats, for example, rose from 12¢ a bushel the previous year to 92¢ a bushel.
<<
Before Petronius Arbiter?
“We trained hard - but it seemed that every time we were beginning to form up into teams we were reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing, and what a wonderful method it can be for creating the illusion of progress while actually producing confusion, inefficiency, and demoralization.”
- Petronius Arbiter 210 B.C.
B.P.: Before Present.
“10000 B.P.” is a more obnoxious way of saying “10,000 years ago.”
*snort*
Ohhkay. Sounds so much more academic than 10,000 years ago. /s
|
|
|
| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
|
|
Just updating the GGG information, not sending a general distribution. |
|
|
|
|
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.