Plant cultivation earlier
- NEW YORK TIMES
June 29, 2007
Squash Seeds Show Andean Cultivation Is 10,000 Years Old, Twice as
Old as Thought
By JOHN NOBLE WILFORD
Seeds of domesticated squash found by scientists on the western
slopes of the Andes in northern Peru are almost 10,000 years old,
about twice the age of previously discovered cultivated crops in the
region, new, more precise dating techniques have revealed.
The findings about Peru and recent research in Mexico,
anthropologists say, are evidence that some farming developed in
parts of the Americas nearly as early as in the Middle East, which is
considered the birthplace of the earliest agriculture.
Digging under house floors and grinding stones and in stone-lined
storage bins, the archaeologist Tom D. Dillehay of Vanderbilt
University, in Nashville, uncovered the squash seeds at several
places in the �anchoc Valley, near the Pacific coast about 400 miles
north of Lima. The excavations also yielded peanut hulls and cotton
fibers � about 8,500 and 6,000 years old, respectively.
The new, more precise dating of the plant remains, some of which were
collected two decades ago, is being reported by Dr. Dillehay and
colleagues in today�s issue of the journal Science.
Their research also turned up traces of other domesticated plants,
including a grain, manioc and unidentified fruits, and stone hoes,
furrowed garden plots and small-scale irrigation canals from
approximately the same period of time.
The researchers concluded that these beginnings in plant
domestication �served as catalysts for rapid social changes that
eventually contributed to the development of intensified agriculture,
institutionalized political power and towns in both the Andean
highlands and on the coast between 5,000 and 4,000 years ago.�
The evidence at �anchoc, Dr. Dillehay�s team wrote, indicated that
�agriculture played a more important and earlier role in the
development of Andean civilization than previously understood.�
In an accompanying article on early agriculture, Eve Emshwiller, an
ethnobotanist at the University of Wisconsin, Madison, was quoted as
saying that the reports of early dates for plant domestication in the
New World were remarkable because this appeared to have occurred not
long after humans colonized the Americas, now thought to be at least
13,000 years ago.
The article also noted that 10,000-year-old cultivated squash seeds
had recently been reported in Mexico, along with evidence of
domesticated corn there by 9,000 years ago. Scholars now think that
plants were domesticated independently in at least 10 �centers of
origin,� including, in addition to the Middle East, Mexico and Peru,
places in Africa, southern India, China and New Guinea.
In the Fertile Crescent of the Middle East, an arc from modern-day
Israel through Syria and Turkey to Iraq, wheat and barley were
domesticated by 10,000 years ago, and possibly rye by 13,000 years
ago. Experts in ancient agriculture suspect that the transition from
foraging to cultivation had started much earlier and was not as
abrupt a transformation as indicated in the archaeological record.
Dr. Dillehay has devoted several decades of research to ancient
cultures in South America. His most notable previous achievement was
the discovery of a campsite of hunter-gatherers at Monte Verde, in
Chile, which dates to 13,000 years ago. Most archaeologists recognize
this as the earliest well-documented human occupation site uncovered
so far in the New World.
Other explorations in recent years have yielded increasing evidence
of settlements and organized political societies that flourished in
the coastal valleys of northern Peru possibly as early as 5,000 years
ago. Until now, the record of earlier farming in the region had been
Initial radiocarbon dating of the plant remains from �anchoc was
based on wood charcoal buried at the sites, but the results varied
widely and were considered unreliable. More recent radiocarbon
dating, with a technique called accelerator mass spectrometry, relied
on measurements from undisturbed buried charcoal and an analysis of
the actual plant remains.
The distribution of building structures, canals and furrowed fields,
Dr. Dillehay said, indicated that the Andean culture was moving
beyond cultivation limited to individual households toward an
organized agricultural society.
Botanists studying the squash, peanut and cotton remains determined
that the specific strains did not grow naturally in the �anchoc area.
The peanut, in particular, was thought to be better suited to
cultivation in tropical forests and savannas elsewhere in South America.
The wild ancestor of squash has yet to be identified, though lowlands
in Colombia are thought to be a likely source.
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