Agriculture Reference
In-Depth Information
(before birth to age 12). In addition, anthropologists have documented reduced rates
of growth as estimated by comparison of lengths of limb bones of children at specific
ages and adult heights (various mentions in Cohen and Armelagos 1984, Steckel and
Rose 2002, Cohen and Crane-Kramer 2007). Thus, early farmers tend to be shorter
as both children and adults than early foragers or in comparison with modern popu-
lations with abundant nutrition. A variety of evidence gathered by nutrition scien-
tists indicates that meat provides the only full complement of essential amino acids
necessary for growth and development, not to mention a range of micronutrients
(various authors as mentioned in Demment and Allen 2003). The decline in growth
rate and adult height almost certainly reflects the reduced availability of high-quality
nutrition associated with the dependence on plant domesticates, which lack essential
amino acids and other key nutrients.
eARly fARmIng And lIfestyle
One of the big debates among anthropologists (and any scholar interested in the
foraging-to-farming transition) is how agriculture, once in place, improved (or not)
our quality of life, including workload. Simply put, did agriculture and the farming
lifestyle require more work or less work than foraging? Braidwood (1967) obviously
believed that the transition occasioned a decline in workload as food sources derived
from crops and domesticated animals became more predicable. About the time that
Braidwood was writing about early farmers, Richard Lee, a cultural anthropologist,
had begun a long-term ethnographic study of the Ju/'hoansi (!Kung) of southern
Africa. He lived with this group for years, documenting the foods they ate and the
amount of work time versus leisure time. Much to his surprise, he discovered that
for this particular foraging group, they had loads of leisure time, and by inference,
perhaps hunting and gathering may not have been all that tough (Lee 1968).
This research created a firestorm in the anthropological community and impor-
tantly set up a series of hypotheses and questions, some of which are being addressed
by physical anthropologists. How can we tell from ancient skeletal remains how hard
(or easy) past lifeways were? Is it possible to reconstruct workload and activity levels
in the past? Indeed it is, and one avenue for understanding past lifestyles is via the
study of bone structure and its links to behavior. When a person is alive, that person's
bone tissue is highly plastic, especially when the bones are growing and maturing
prior to adulthood. In the nineteenth century, the German anatomist Julius Wolff
observed that when bone is “stressed,” it increases where it is needed to resist stress.
On the other hand, where stress is reduced, bone is taken away. Thus, a high level of
physical activity over the course of a person's lifetime will result in bigger, stronger
bones. Similarly, at the population level, a group of people who are physically active
will have skeletons that are more robust than a group of people who are less physi-
cally active. Indeed, living human groups show this association between activity
level and bone size. Anthropologists have also applied the science of biomechanical
engineering to measure the strength of bones. Engineers measure the strength of
building materials—like the “I” beams that are used to build the infrastructure of
a building or bridge—based on the premise that a cross section that has material
placed furthest from its center is stronger than a cross section where the material is
