Environmental Engineering Reference
In-Depth Information
process makes these ideas untenable. Nor were new
tools, cereal processing, sedentism, or storage habits the
necessary prerequsities. Simple tools (wooden sticks,
stone-chip cutting blades) that were already in use for
millennia sufficed. The earliest confirmation of pound-
ing and grinding of some wild cereals and using the
flour in baking comes from an Upper Paleolithic site
(19,500
B
.
C
.
E
.) in Israel, at least 12,000 years before the
domestication of cereals (Piperno et al. 2004). Neolithic
¸ atalh
¨
y¨k and A¸ıkli on the Anatolian Plateau were
settlements with complex arrangements of buildings
housing thousands of people that subsisted mostly on
hunting and gathering (Balter 1998), whereas the
Tehuac´n Valley had no permanent settlements but
thousands of years of crop cultivation (Bray 1977). There
are numerous examples of food storage among foragers
and its absence among gardeners.
Many foraging societies coexisted side by side with
agriculturalists; farming had no irresistible, automatic
universal appeal. Why it arose—independently in at least
seven locations on three continents, between 10,000 and
5,000 years ago—is perhaps the most challenging evolu-
tionary, archaeological, and anthropological puzzle that
may never have a definite solution (Megaw 1977; Man-
nion 1999; Armelagos and Harper 2005). Environmen-
tal explanations (well-documented climate changes) have
a long tradition (Childe 1951; Byrne 1987). The latest
contribution in this category concludes (despite the accu-
mulated knowledge) that Paleolithic agriculture was im-
possible (climate too dry, CO
2
levels too low) whereas
Neolithic agriculture was mandatory (Richerson, Boyd,
and Bettinger 2001). In contrast, evolutionary explana-
tions see diminishing returns in gathering and hunting
brought by slow growth of foraging populations, gradual
extension of incipient cultivation techniques (present in
most foraging societies), and a slow adoption of a greater
variety of cultivation practices (Cohen 1977).
But cultural factors should not be neglected. Crop
cultivation fosters association, a desirable goal for our
sociable species. At the same time, farming promotes
individual ownership and accumulation of material pos-
sessions; it makes it easier to have larger families; and it
facilitates warfare. Orme (1977) has gone too far when
concluding that food production as an end in itself may
have been unimportant, but there is no doubt that social
co-factors are important, some having little or nothing to
do with food. After all, net returns of many early field
harvests were in no way superior to those of some forag-
ing practices, and hence the adoption of farming cannot
be seen as a quest for maximized energy returns. Quality
considerations (ignored by common energy denomina-
tors) were important: domestication of cereal and oil
plants can be readily explained because of their high pro-
tein or lipid content rather than because of any general-
ized quest to minimize energy expenditures.
Whereas the transition from foraging to farming
was initiated and sustained by a complex of energetic,
nutritional, and social impulses, the further evolution of
agriculture can be seen as a matter of clear energy imper-
atives. Boserup (1965; 1976) elaborated this link with
great clarity when looking at the evolution of peasant
societies. As a particular food production system reaches
its limits, the affected population can migrate, stay, and
stabilize; stay and decline; or adopt a more productive
subsistence. The last option may not initially be any
more appealing or probable than the others. When it
comes, the shift requires higher energy inputs, so even
with higher food production density the net return ratio
may decline, but the higher edible energy flux will sup-
port a larger population.
