When early humans hunted and gathered food, they
were not in control of their environment. They could
only interact with their surroundings as lower
organisms did. When humans learned to make fire,
however, they became capable of altering their
environment. To provide themselves with fuel they
stripped bark from trees, causing the trees to die.
Clearings were burned in forests to increase the
growth of grass and to provide a greater grazing area
for the wild animals that humans fed upon. This
development led to farming and the domestication of
animals. Fire also provided the means for cooking
plants which had previously been inedible. Only when
the process of meeting the basic need for food
reached a certain level of sophistication was it
possible for humans to follow other pursuits such as
the founding of cities.
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