Pre-Darwinian Theories

Despite his criticism of Lamarck, George
Cuvier did not reject the idea that there had
been earlier life forms. In fact, he was the first
scientist to document extinctions of ancient
animals. However, he rejected the idea that
their existence implied that evolution had
occurred--he rigidly maintained the "fixity" of
species.
Cuvier advocated the theory of catastrophism
. This held that there have been violent and
sudden natural catastrophes such as great
floods and the rapid formation of major
mountain chains. Plants and animals living in
those parts of the world where such events
occurred were often killed off according to
Cuvier. Then new life forms moved in from
other areas. As a result, the fossil record for a
region shows abrupt changes in species.
Charles Lyell
1797-1875
A careful examination of
European geological
deposits led the English
scientist, Charles Lyell ,
to conclude that Cuvier's
catastrophism theory was
wrong. He believed that
there primarily have been
slower, progressive
changes. Lyell
documented the fact that the Earth must be
very old and that it has been subject to the
same sort of natural processes in the past that
operate today in shaping the land. These
forces include erosion, earthquakes, glacial
movements, volcanoes, and even the
decomposition of plants and animals.
Lyell provided conclusive evidence for the
theory of uniformitarianism , which had
been developed originally by the late 18th