The Evolution of Foraging - Harvesting the Biosphere - page 75

or above l ames on sticks, encased in a tough skin or a thin clay covering, placed
in simple stone ovens, or cooked with hot stones added to leather pouches i lled
with water, and, of course, it can be consumed in states ranging from only lightly
singed to much overcooked.
Cooking methods have very different energy conversion efi ciencies, dei ned in
this case as the quotient of the heat transferred to plant or animal tissues to cook
them to a desired consistency and the heat content (chemical energy) of the phyto-
mass needed to maintain a i re during the cooking period. Experiments have estab-
lished actual efi ciencies ranging from only a few percent to as much as 10%. A
plausible set of deliberately generous assumptions (to set a likely high limit) indicates
that the annual consumption of wood (or other phytomass) for cooking was 100-
150 kg per capita (box 7.1).
Even if the outlined calculation errs by as much as two orders of magnitude,
there can be no doubt that Paleolithic cooking i res had a negligible impact on the
biosphere's phytomass stores. More important, even if we had near-perfect informa-
tion about typical cooking practices and frequencies, we still could not quantify the
amount of woody phytomass used in prehistoric campsites with any reasonable
degree of accuracy because campi res were set and maintained not just for cooking
but also for defense against large predatory animals, protection against insects, and
the provision of heat and light, and many of those i res led to accidental grassland
or forest i res.
Hominin consumption of the heterotrophic zoomass began with collecting
insects, small invertebrates, and mollusks and scavenging the carcasses of animals
(Domínguez-Rodrigo 2002). Larger animals could be killed only with larger
weapons, and throwing spears date back to 400,000-380,000 years ago (Thieme
1997), predating the emergence of early modern humans, which is now dated to
around 195,000-150,000 years ago (Trinkhaus 2005). The cooperative hunting of
large animals (fallow deer, aurochs, horses, wild pigs, asses) and subsequent meat
sharing is convincingly demonstrated by tool marks on animal bones found at
Qesem Cave in Israel during the period 400,000-200,000 years ago (Stiner, Barkai,
and Gopher 2009). In contrast, the i rst bows and arrows appear in the archaeologi-
cal record only about 25,000 years ago
The antiquity of the human quest for meat is not at all surprising: decades of
i eld studies of chimpanzees, our closest primate ancestors, have shown that not
only the common chimpanzees ( Pan troglodytes ) but also the smaller bonobos ( Pan
paniscus) are fairly regular hunters and consumers of meat. Small monkeys (particu-
larly the red colobus) are the species most often targeted by common chimpanzees,