posted 28 July 2004 11:15 PM            

Archaeologists have long believed that food production
developed worldwide much the way it did in the Near East:
as climate changes made wild grains less available, hunters
and gatherers settled in villages and relatively quickly
domesticated plants and then, over the next few thousand
years, animals.

But recent genetic studies and excavations in Africa
suggest that the patterns of domestication there were
strikingly different. This new research, emerging in the
last few years in academic books and articles, shows that
in Africa, wild cattle were domesticated several thousand
years before plants, and that farming and herding spread
patchily and slowly across the continent.

Why Africans were relatively late to take up farming and
where the domestication of wild grains first happened are
now the subjects of intense research. One theory is that
wild grain was so abundant throughout the continent that
there was no need to settle down to farming. Already the
new discoveries have caused archaeologists to adjust their
thinking about how societies evolved and to realize how
assumptions arose from concepts developed for the Near
East, where most archaeological work has been done.

"African scholars kept expecting to find domestic plants
very early because the model from the Near East was driving
the thinking on Africa," said Dr. Fiona Marshall, an
archaeologist at Washington University in St. Louis who in
a 2002 article in The Journal of World Prehistory was among
the first to recognize that Africa followed a different
paradigm. "It took us a long time to see that we had a
different pattern."

As Dr. Angela E. Close, an archaeologist at the University
of Washington, put it: "There was this idea that once you
get domesticated plants or animals, or both, then you
become a farmer. But a number of peoples didn't do this."

For archaeologists, the story of how Near Eastern hunters
and gatherers became farmers has become as familiar as a
bedtime fable. Beginning as early as 11,000 B.C., people
settled into villages and began cultivating wild grasses
like rye, emmer wheat and barley. Over time, the genetic
makeup of the plants changed, so they needed to be sown and
tended in order to grow.

Cows, goats and sheep were domesticated over the next few
thousand years, and then ceramics were developed to store
food. This new way of life quickly swept across Europe and
much of Asia. Soon, almost everyone was farming.

But not in Africa. As Dr. Katharina Neumann, an
archaeobotanist at the J. W. Goethe University in
Frankfurt, noted in the book "Food, Fuel and Fields -
Progress in African Archaeobotany,'' published last year,
archaeologists at several sites across sub-Saharan Africa
have not found evidence of domesticated grains before 2000
B.C., suggesting that until then, people collected wild
grains and did not plant their own.

While the first undisputed remains of domesticated cattle
appear in the African archaeological record about 5900 B.C.
at a site in Chad, other studies suggest that cattle were
domesticated in the same region as early as 9,000 years
ago.

A study of African cattle published in the journal Science
in 2002 suggested that cattle were domesticated
independently in Africa, rather than being imported from
the Near East, as they were across most of Europe and Asia.

Dr. Close said the first pastoralists in Africa, who
traveled with domesticated cattle, had probably captured
wild animals at first to provide insurance as the Sahara,
then partly covered in grassland, began to dry. They moved
south to savannas to find moister conditions. These
"cattle-assisted hunter gatherers," as she called them,
took milk, blood and meat from their animals.

Some pastoralists began to worship cattle, burying them in
elaborate graves. At sites across the Sahara, cattle images
appear in rock art.

Pastoralism gradually spread west across the southern
Sahara, and then south, reaching the equator around 2000
B.C. and South Africa by the first centuries A.D. Like the
hunter-gatherers with whom they shared their environment,
pastoralists made great use of the abundant wild African
grasses growing in the savanna, but did not plant them.
Both groups also made ceramics, an innovation that in the
Near East came only with settled agricultural villages.

By 5500 B.C., domesticated wheat, barley, sheep and goats
arrived in Egypt from the Near East. These animals were
adopted by cattle-herding pastoralists along the Sahara's
southern rim, but the grains did not make it beyond Egypt,
probably because they require winter rain, and in most of
Africa the rains come in summer. Still, archaeologists
wonder why the idea of planting, if not the crops
themselves, did not catch on.

In an article to be published in September in the book
"African Archaeology: A Critical Introduction," Dr. Neumann
says there is an implicit assumption among archaeologists
that "agriculture is superior to the foraging of wild
plants and that with the invention of agrarian practices,
economies based on wild resources are no longer
competitive."

But she said in an interview that there was no need for
African hunter-gatherers to settle down as farmers.
Savannas, which cover 80 percent of sub-Saharan Africa,
provided people with a vast garden of Eden. Since they were
so mobile, hunter-gatherers and pastoralists could take
advantage of many varieties of wild grasses, fruits, tubers
and game.

So successful were these strategies that foraging
populations like the !Kung San of southern Africa survived
until the end of the last millennium, while some in the
Tuareg and Zaghawa societies of central Africa still make a
living by herding and foraging.

Some archaeologists argue that as in the Near East, some
African populations began to plant grains because the
climate turned drier, threatening their food security.
Archaeologists are also trying to understand who the first
farmers were, whether hunter-gatherers or pastoralists, and
whether they were sedentary.

Cattle bones turn up at some sites with domesticated
millet, suggesting that pastoralists had begun to plant.
Sometimes these farmers lived in villages, but other times
there is little evidence of sedentary life.

The first native African grass to be domesticated was pearl
millet. Impressions of the grain found in ceramics at Dar
Tichitt in Mauritania date to about 1800 B.C., but
archaeobotanists are excited about a recent find by Dr.
Cathy D'Andrea of Simon Fraser University in Canada, from
the Kintampo culture in Ghana that dates to 1740 B.C.

Comparisons of the proteins of wild and domesticated grains
suggest that domestication probably happened twice in
western Africa - in Mauritania and in the Air Mountains of
Niger. Sorghum, the second grain domesticated in Africa,
appears only in the first century A.D.

Although they lack direct evidence, scholars know that
pearl millet had to have been domesticated earlier in
Africa, probably sometime between 2500 and 3000 B.C. The
reason is that domesticated pearl millet has turned up at
archaeological sites in India that are contemporaneous with
its earliest occurrence in the African record, said Dr.
Dorian Fuller, an archaeobotanist at University College
London.

The theory, Dr. Fuller said, was that the domesticated
grain moved east from western Africa along the southern
Sahara to the coast, and was spread to India by traders who
sailed the Arabian Sea.

The oldest domesticated plant in Africa is not a grain but
the humble ancestor of today's juicy watermelon,
domesticated seeds of which dating to 4000 B.C. were found
in the 1980's in southern Libya.

"The wild watermelon is a horrible, dry little gourd that
grows in the wadis of the northern savanna, but it has
seeds you can roast up and eat," Dr. Fuller said. (The
watermelon we eat now was not developed until Roman times.)

Dr. Fuller said the findings of domesticated watermelon
seeds support a hypothesis held by Dr. Marshall and her
Washington University colleague Dr. Elisabeth Hildebrand,
who studied how modern people in northern Africa manipulate
wild plants. The archaeologists suggest that people begin
domesticating a plant not necessarily to increase yield, as
Near Eastern farmers did, but because they want to be sure
to have a certain plant when they want it - either for some
ritual use or just because they like it.

The people in Libya, Dr. Fuller said, may have planted
watermelon seeds so they always had a tasty snack on hand.
http://www.nytimes.com/2004/07/27/science/27farm.html