It's pretty well accepted fact that once agriculture emerged as a dominant
aspect of human life, societies developed, leaving the hunter-gatherer
time period behind.
This fundamental transition that has led to the establishment of modern
society is known as the "Neolithic revolution" and it occurred
independently in at least seven parts of the world.
But what is not as readily accepted is that change could have been dramatically
affected by environmental changes. Various hypotheses range from environmental
changes to social causes.
A group of scientists from throughout the world, including an Iowa State
faculty member, is exploring the effect that environmental changes had
in the eastern Mediterranean region where the oldest evidence of farming
is found.
Cinzia Cervato, assistant professor of geological and atmospheric sciences,
and her colleagues are hoping by studying the temperature and precipitation
records from marine sediments across the Mediterranean Sea, to figure
out what triggered the agricultural movement.
Cervato has been funded for the project, "Human Response to Global
Change: Using the Marine Record to Establish Environmental Gradients Across
the Mediterranean at the Time of First Emergence of Agriculture and Ensuing
Dispersal," through a University Research Grant (URG).
The $18,000 grant is part of a program administered by the Office of the
Vice Provost for Research. The purpose of these grants is to provide "seed"
money to begin research or scholarship that is expected to continue developing
and to attract funding from other sources beyond the period covered by
the "seed" funding.
Cervato has utilized the funds to help set up a laboratory. She and her
project collaborators from Harvard University, Columbia University, Istanbul
University in Turkey and the Portuguese Institute of Archeology are seeking
additional funding from the National Science Foundation and other sources.
Extreme environmental factors during the last ice age kept the hunter-gatherers
on the move. That kept the birth rate low and the population remained
stable. But once the climate changed, so did society.
"Scholars have diverged in their explanation concerning the question
of why foragers started cultivation, which led to the domestication of
annual plants, and later penned, tended and herded goats, sheep, cattle
and pigs," Cervato said.
"These records will provide valuable insight into the regional environmental
conditions and broad climatic gradients between the Near East and Iberia,"
Cervato said. "We propose to exploit the marine record of pelagic
sediments in this area (Mediterranean Sea, Red Sea and Gulf of Aden) to
determine the rate of temperature and precipitation changes in the region
and environmental gradients across the Mediterranean prior to, during,
and after the proposed beginning of farming."
When the last ice age ended, semi-nomadic groups settled in the Fertile
Crescent (modern-day southern Turkey, Syria, Israel, Lebanon, Jordan and
Iraq) because of its abundant water supply, plentiful vegetation and wildlife.
The population started to depend heavily on the variety of food in this
area.
"This area was thriving with wild plants and wild animals,"
Cervato said. "In fact, 80 percent of today’s domesticated plants
and animals were originally from this area."
Climate records indicate that when the temperature suddenly decreased
and conditions closer to the ice age were established, the population
moved out of the primitive villages that had started to grow in the region.
But when the temperatures increased after a few centuries, the population
went back to the original sites and brought with them domesticated plants
and animals.
For this reason, Cervato and her colleagues hypothesize that the transition
to agriculture occurred 12,000 years ago during a cold spell known as
the Younger Dryas.
"They started to domesticate animals and the population expanded
because of the change in the culture and nutrition," Cervato says.
This new way of life rapidly spread to the shores of the eastern Mediterranean
and within 3000 years farming was brought to the whole Mediterranean region.
Cervato and her colleagues hope to collect additional climate record data
from this area, which will be entered into a relational database and made
accessible on the web.
"We hope to find out if climate had something to do with early farming,"
Cervato said.
