Download Box 5.2 Was Cooking the Driving Force of Human Evolution?

Box 5.2
Was Cooking the Driving Force
of Human Evolution?
Anthropologists are often interested in the
driving force of human evolution. One
popular hypothesis is that the driving force
was cooking. The hypothesis is valid, but is not
widely accepted. It makes sense to many, but
skepticism remains because of the lack of
evidence in the archaeological record, including
the lack of evidence for the control of fire close
to two million years ago.
The person most often associated with the
hypothesis that cooking was the driving force
of human evolution is Richard Wrangham, who
outlined his hypothesis in the book Catching
Fire: How Cooking Made Us Human, published in
2009. He summarizes his idea as follows:
I believe the transformative moment that
gave rise to the genus Homo, one of the great
transformations in the history of life, stemmed
from the control of fire and the advent of
cooked meals. Cooking increased the value
of our food. It changed our bodies, our brains,
our use of time, and our social lives. It made
us consumers of external energy and thereby
created an organism with a new relationship
to nature, dependent on fuel. (p. 2)
Wrangham suggests that the initial change
that made us human was increased meat
eating about 2.5 million years ago (associated
with Homo habilis), followed by cooking about
1.8 million years ago (associated with Homo
erectus). He describes the value of cooking:
Cooked food does many familiar things.
It makes our food safer, creates rich and
delicious tastes, and reduces spoilage.
Heating can allow us to open, cut, or mash
tough foods. But none of these advantages is
as important as a little-appreciated aspect:
cooking increases the amount of energy our
bodies obtain from our food.
The extra energy gave the first cooks
biological advantages. They survived
and reproduced better than before. Their
genes spread. Their bodies responded by
biologically adapting to cooked food, shaped
by natural selection to take maximum
advantage of the new diet. There were
changes in anatomy, physiology, ecology,
life history, psychology, and society. Fossil
evidence indicates that this dependence arose
not just some tens of thousands of years ago,
or even a few hundred thousand, but right
back at the beginning of our time on Earth, at
the start of human evolution, by the habiline
that become Homo erectus. (pp. 13–14)
In humans, because we have adapted to
cooked food, its spontaneous advantages are
complemented by evolutionary benefits. The
evolutionary benefits stem from the fact that
digestion is a costly process that can account
for a high proportion of an individual’s energy
budget—often as much as locomotion does.
After our ancestors started eating cooked
food every day, natural selection favored
those with small guts, because they were
able to digest their food well, but at a lower
cost than before. The result was increased
energetic efficiency. (p. 40)
© 2016 University of Toronto Press
While it is widely accepted that early Homo incorporated some meat in their diet,
the significance of meat and the adoption of hunting strategies clearly increased
with the emergence of Homo erectus. The driving force may be linked with the use
of fire for cooking, although this idea is controversial. (See Box 5.2.)
There is considerable evidence that hunting, at least for the past few hundred
thousand years, included big game such as mammoths and mastodons. This would
Chapter 5: Human Cultural Evolution from 2.5 Million to 20,000 Years Ago
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2015-09-23 12:11 PM