Environmental Engineering Reference
In-Depth Information
extensive forest i res. This means that the most important human impact on preag-
ricultural ecosystems came i rst because of the use of i re and later (when weapons
and hunting tactics allowed it) from the hunting of megaherbivores.
The importance of i re in human evolution is easily exaggerated, but it cannot
be denied. The date of the i rst controlled use of i re will always remain elusive: the
long-term preservation of any convincing evidence in the open is highly unlikely,
and evidence of the earliest i res inside an occupied cave was destroyed by genera-
tions of later use. The earliest date for an incontrovertibly proven controlled use of
i re use has been receding: in the early 1990s Goudsblom's (1992) most likely timing
was about 250,000 years ago, but by the early 2000s the date had been pushed as
far back as 790,000 years ago (Goren-Inbar et al. 2004). The fossil record suggests
that the consumption of some cooked food could go as far back as 1.9 million years
ago, but unequivocal evidence for the widespread use of i re goes only to the Middle
Paleolithic (300,000-200,000 years ago), the period when
Homo sapiens sapiens
displaced the European Neanderthals (Bar-Yosef 2002; Karkanas et al. 2007).
Not long afterward, people also began to use i re as an engineering tool: as early
as 164,000 years ago early modern humans were heat treating stones to improve
their l aking properties (Brown et al. 2009), and Mellars (2006) has suggested that
the controlled burning of vegetation may have been done in South Africa as early
as 55,000 years ago. But we cannot reconstruct any meaningful record of such
controlled burning, and the heat treating of stones could not have translated into a
major demand for wood. This leaves cooking, an activity that has always been seen
as an important component of human evolution but that was elevated by Wrangham
(2009) to having a “monstrous” effect on our ancestors.
Wrangham argues that cooking enormously increased the range of foods homi-
nins could eat (undoubtedly true), as well as the food quality (a debatable proposi-
tion, as there is no easy way to compare easier digestion with the loss of various
nutrients), and that the adoption of cooking resulted in many fundamental physical
and behavioral changes ranging from smaller teeth and a less voluminous digestive
tract to the necessity of defending stealable patches of accumulated food (which in
turn promoted protective female-male bonds) and eventually led to complex social-
ization, sedentism, and “self-domestication.”
Such claims and counterclaims are easy to make, but the impact of universally
adopted frequent cooking on the biosphere is impossible to quantify beyond some
plausible indications. All prehistoric cooking was done with simple open i res, but
that still leaves a number of possibilities: food can be cooked directly on slow-
burning pieces of wood, buried in hot embers, placed on hot rocks, suspended in
