Title: What the Nubians ate.
Author(s): Svitil, Kathy A.
Source: Discover; Jun94, Vol. 15 Issue 6, p36, 2p, 1c
The desiccated skin and hair of mummies from the Nubian Desert reveal
what ordinary Nubians ate a millennium or two ago.
The nubians were kings once: they built pyramids and temples, carved
delicate statues and jewelry, controlled trade along the Nile, and for
a
century. or so, beginning in the eighth century B.C., even ruled Egypt,
their neighbor to the north. Mostly, though, the Nubians have been
pawns, invaded by the Persians and Assyrians, dominated by the
Egyptians--and finally flooded. When the Aswan High Dam was completed
in
1970, the reservoir it created inundated thousands of square miles of
land along the bank of the Nile, from Egypt south into the Sudan.
Nearly
all of what was once the Lower Nubian heartland is now LakeNasser.
Before the flood, however, teams of archeologists from around the world
flocked to the region, hurriedly salvaging what they could of the
Nubian
past. They recovered tons of ancient artifacts-including the entire
Temple of Dendur, which now stands in the Metropolitan Museum of Art in
New York and, even more remarkably, hundreds of ancient Nubians. Most
of
these mummies were ordinary folk, buried in the desert and accidentally
preserved by the blistering heat and dry, sands; their bodies dried out
so fast that not only the bones but also the skin, hair, and muscle
were
saved from decomposition. And preserved along with the mummies, says
Christine White, a physical anthropologist at the University of Western
Ontario, is a record of what the ancient Nubians ate--even in the last
weeks of their lives. White gleaned that particular bit of information
from the mummies' hair.
Researchers already knew that the ancient Nubians' diet was inadequate;
besides evidence of arthritis, tumors, and parasites, the mummies show
clear signs of malnutrition, iron-deficiency anemia,and osteoporosis.
Yet what that diet consisted of has been something of a mystery.
Despite
the intensive excavation, no physical evidence--plant or animal
re-mains--was ever recovered. White has now extracted that physical
evidence from the mummies themselves by looking at the isotope
signatures of their tissue: the distinctive ratios of heavy nitrogen
atoms to light ones and of heavy to light carbon that humans acquire
from the plants and animals they eat.
White studied 167 mummies from a site along the west bank of the Nile
in
the Wadi Halfa region of northern Sudan. The oldest mummies dated from
the period between 350 B.C. and A.D. 350, when Lower Nubia was ruled by
the Meroitic Empire of Upper Nubia. White first looked at the mummies'
nitrogen signature to find out their source of protein (which is rich
in
nitrogen). Grasses and the cows that eat them have a relatively low
ratio of heavy nitrogen 15 to nitrogen 14; scrubs and bushes and the
goats and sheep that browse on them in the Nubian Desert have a higher
ratio. Most of the mummies, White found, had eaten these desert animals
rather than cattle. Some had partaken more than others: male mummies
contained more nitrogen 15 relative to their body weight than did
females. Apparently the men of ancient Nubia got more than their fair
share of the meat.
The ancient Nubians did not just ranch in the desert. They also made it
bloom--and with crops that aren't easy to grow in hot, arid conditions.
The ratio of carbon 13 to carbon 12 in the mummies from the Meroitic
period, says White, shows that fully 84 percent of the Nubians' plant
intake consisted of "C3" foods like wheat, barley, and fruit--all of
which require more water than is normally available in the Nubian
Desert. (C3 plants shun the heavier carbon isotope and so have a lower
isotope ratio than desert-adapted C4 plants.) The Nubians, White
figures, must therefore have been irrigating their crops, probably
using
the ox-driven waterwheel--a sort of Ferris wheel with buckets that
dumped water from the Nile into irrigation channels. It was invented in
Mesopotamia and brought to Lower Nubia by Meroitic settlers.
Lower Nubia, White speculates, may have been an agricultural hinterland
that produced wheat and barley for Meroe. That might explain why
mummies
dating from after the fall of the Meroitic Empire around A.D. 350 ate
about 9 percent fewer C3 plants than their forebears. "When the
Meroitic
Empire fell," White says, "the Nubians, who no longer had to grow so
much wheat and barley, may have reverted to a more traditional diet of
C4 plants, like sorghum and millet." Such grains are much easier to
grow
in the desert than C3 crops, even with irrigation.
Today in the Wadi Halfa, wheat and barley are grown in the fall and
winter, with the aid of irrigation and the annual flooding of the Nile,
while sorghum and millet are planted in the spring and harvested
beginning in early June. Could the same crop rotation, White wondered,
have been occurring over a thousand years ago? The mummies' hair said
yes. Until White's work, only bone had been used in isotopic analyses,
and bone takes between 25 and 30 years to replace its store of
isotopes--making its isotope signature "just a homogenized version of
what was consumed over a lifetime," as White puts it. But isotopes show
up in hair two weeks after they're consumed. Thus isotope signatures
from increments along a hair shaft can reveal any changes in diet that
occurred while the hair was growing.
White cut hair from 14 post-Meroe mummies into three-quarter-inch-long
segments, each segment representing about two months' growth. She found
that the isotopic signature fluctuated dramatically between segments,
indicating that the person had alternated between periods of eating
mostly C3 plants and ones of relying on C4 plants. Furthermore, by
looking at the hair closest to the scalp, White could tell what the
future mummies had eaten just weeks before they died. Nearly two-thirds
of them had been eating C4 plants. That suggested they died after the
sorghum and millet harvest in June, but before the wheat and barley
harvest in the winter.
Why would more Nubians have died during summer? Because of heat and
malnutrition, says White. C4 plants aren't as nutritious as C3 plants;
sorghum is low in vitamin B, for instance, and vitamin B deficiency
increases the incidence of pellagra, a disease that causes
gastrointestinal and neurological problems. Moreover, by the end of
summer in Nubia, even C4 crops are scarce. Today more residents of the
Nubian Desert die in summer than during any other time of year. One
thousand years ago, their ancestors may have faced the same hardships.
PHOTO (COLOR): He died in summer, judging from the last meals recorded
in his hair.
~~~~~~~~
By KATHY A. SVITIL