Lecture 23: Change in the Paleolithic Era
“¿ restick farming” to describe how Australian aboriginal communities used
¿ re to manage their environments. By regularly ¿ ring the land, they limited
uncontrolled ¿ res and stimulated new plant growth, which attracted prey
species such as kangaroo. Similar practices were used in other parts of the
world, including North America. Over thousands of years, ¿ restick farming
transformed entire landscapes. In Australia, for
example, it encouraged the spread of ¿ re-resistant
species such as eucalypts. This means that the
landscapes observed by the ¿ rst Europeans to
encounter Australia were not “pristine” at all; in
their way, they were as manicured as the gardens
of 18th-century Europe.Humans may also have driven many large mammal
species to extinction in a series of “megafaunal
extinctions.” In the last 50,000 years, many large mammal species have died
out, including mammoth, giant kangaroos, saber-toothed tigers, and North
American horses. Most extinctions occurred in newly colonized lands such
as Australia and the Americas. In Australia, 70% of mammals over 44 kg in
weight may have vanished (about 60 species).The dates of these extinctions suggest that they coincided with the arrival of
humans and may have been caused by overhunting, though climatic changes
may also have played some role. “Megafaunal extinctions” transformed the
biota of entire continents. However, there still remains disagreement about
the precise contribution of humans to these extinctions. Among the earliest
victims of our increasing ecological power were our closest relatives, Homo
ergaster and Homo neanderthalis, both of which vanished about 20,000 to
30,000 years ago.We have seen that a lot happened in the Paleolithic era, a clear sign of
our species’ remarkable capacity for adaptation and innovation. By the
end of the last ice age, 10,000 years ago, humans had spread to all parts
of the world, and there was no room left for further “extensi¿ cation.”
Then, in several quite separate parts of world, a new type of technology
appeared: agriculture. ŶIn Australia, 70%
of mammals over
44 kg in weight
may have vanished
(about 60 species).