Why Humans Became Food Producers 233domestication was practiced. Investigators have deter-
mined that if the age and/or sex ratios at the site differ
from those in wild herds, the imbalances are due to do-
mestication. Archaeologists documented a sharp rise in
the number of young male goats killed at 10,000-year-
old sites in the Zagros Mountains of Iran. Evidently
people were slaughtering the young males for food and
saving the females for breeding. Although such herd
management does not prove that the goats were fully
domesticated, it does indicate a step in that direction.^6
Similarly, archaeological sites in the Andean highlands,
dating to around 6,300 years ago, contain evidence that
these animals were penned up, indicating the beginning
of domestication.Why Humans Became
Food Producers
Although it is tempting to think that a sudden flash of in-
sight about the human ability to control plants and ani-
mals might have led ancient peoples to domestication, the
evidence points us in different directions. As the following
discussion illustrates, there are several false ideas about
the motivation to becoming food producers.
Contemporary foragers show us that food produc-
tion did not come about from discoveries, such as that
seeds, if planted, grow into plants. These food foragers
are perfectly aware of the role of seeds in plant growth,
that plants grow better under certain conditions than
others, and so forth. Jared Diamond aptly describes
contemporary food foragers as “walking encyclopedias
of natural history with individual names for as many as
a thousand or more plant and animal species, and with
detailed knowledge of those species’ biological charac-
teristics, distribution, and potential uses.”^7 In addition,
food foragers frequently apply their knowledge to ac-
tively manage the resources on which they depend. For
example, indigenous people living in northern Australia
deliberately alter the runoff channels of creeks to flood
extensive tracts of land, converting them into fields of
wild grain. Australian Aborigines choose to continue to
forage while also managing the land.
Second, the switch from food foraging to food produc-
tion does not free people from hard work. In fact, avail-
able ethnographic data indicate just the opposite—thatsites. Paleobotanists can often tell the fossil of a wild
plant species from a domesticated one, for example, by
studying the shape and size of various plant structures
(Figure 10.1).^5
Evidence of Early Animal
Domestication
Domestication also produced changes in the skeletal
structure of some animals. For example, the horns of wild
goats and sheep differ from those of their domesticated
counterparts. Some types of domesticated sheep have no
horns altogether. Similarly, the size of an animal or its
parts can vary with domestication as seen in the smaller
size of certain teeth of domesticated pigs compared to
those of wild ones.
A study of age and sex ratios of butchered animals
at an archaeological site may indicate whether animal
(^6) Zeder, M. A., & Hesse, B. (2000). The initial domestication of goats (Capra
hircus) in the Zagros Mountains 10,000 years ago. Science 287, 2254–2257.
(^7) Diamond, J. (1997). Guns, germs, and steel (p. 143). New York: Norton.
AB C
Figure 10.1 Teosinte (A), compared to 5,500-year-old
maize (B) and modern maize (C). Teosinte, the wild grass
from highland Mexico from which maize originated, is far less
productive and does not taste very good. Like most plants that
were domesticated, it was not a favored food for foraging people.
Domestication transformed it into something highly desirable.
(^5) Gould, S. J. (1991). The flamingo’s smile: Reflections in natural history
(p. 368). New York: Norton.