Professor Mary Pohl conducted an analysis of sediments in the Gulf Coast of Tabasco, Mexico, and concluded that people were planting crops in the "New World" of the Americas around 5,300 B.C. The analysis extends Pohl's previous work in this area and validates principles of microfossil data collection.
The results of Pohl's study, which she conducted along with Dolores R. Piperno of the National Museum of Natural History in Washington, D.C. and the Smithsonian Tropical Research Institute in the Republic of Panama, Kevin O. Pope of Geo Arc Research and John G. Jones of Washington State University, will be published in the April 9-13 edition of the journal Proceedings of the National Academy of Sciences.
"This research expands our knowledge on the transition to agriculture in Mesoamerica," Pohl said. "These are significant new findings that fill out knowledge of the patterns of early farming. It expands on research that demonstrates that maize spread quickly from its hearth of domestication in southwest Mexico to southeast Mexico and other tropical areas in the New World including Panama and South America."
The shift from foraging to the cultivation of food was a significant change in lifestyle for these ancient people and laid the foundation for the later development of complex society and the rise of the Olmec civilization, Pohl said. The Olmecs predated the better known Mayans by about 1,000 years.
"Our study shows that these early maize cultivators located themselves on barrier islands between the sea and coastal lagoons, where they could continue to fish as well as grow crops," she said.
During her field work in Tabasco seven years ago, Pohl found traces of pollen from primitive maize and evidence of forest clearing dating to about 5,100 B.C. Pohl's current study analyzed phytoliths, the silica structure of the plant, which puts the date of the introduction of maize in southeastern Mexico 200 years earlier than her pollen data indicated. It also shows that maize was present at least a couple hundred years before the major onset of forest clearing. Traces of charcoal found in the soil in 2000 indicated the ancient farmers used fire to clear the fields on beach ridges to grow the crops.
"This significant environmental impact of maize cultivation was surprisingly early," she said. "Scientists are still considering the impact of tropical agriculture and forest clearing, now in connection with global warming."
The phytolith study also was able to confirm that the plant was, in fact, domesticated maize as opposed to a form of its ancestor, a wild grass known as teosinte. Pohl and her colleagues were unable to make the distinction after the pollen study. Primitive maize was probably domesticated from teosinte and transported to the Gulf Coast lowlands where it was cultivated, according to Pohl.
The discovery of cultivated maize in Tabasco, a tropical lowland area of Mexico, challenges previously held ideas that Mesoamerican farming originated in the semi-arid highlands of Mexico and shows an early exchange of food plants.
Pohl's PNAS article also addresses misconceptions about the paleoecological method, which recovers microfossil evidence, such as pollen, starch grains, or phytoliths, as opposed to macrofossils or whole plant parts, such as maize cobs. Pohl and her colleagues argue that contamination of samples through the geological processes of sediment mixing is more likely to occur with macrofossils than microfossils.
Mary Pohl | EurekAlert!
How much drought can a forest take?
20.01.2017 | University of California - Davis
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences