It was impossible to have any scientific notion of the method of
evolution in Linne's time, as one of the chief sources of information,
paleontology, was still wholly unknown. This science of the fossil
remains of extinct animals and plants is very closely bound up with
the whole question of evolution. It is impossible to explain the
origin of living organisms without appealing to it. But this science
did not rise until a much later date. The real founder of scientific
paleontology was Georges Cuvier, the most distinguished zoologist who,
after Linne, worked at the classification of the animal world, and
effected a complete revolution in systematic zoology at the beginning
of the nineteenth century. In regard to the nature of the species he
associated himself with Linne and the Mosaic story of creation, though
this was more difficult for him with his acquaintance with fossil
remains. He clearly showed that a number of quite different animal
populations have lived on the earth; and he claimed that we must
distinguish a number of stages in the history of our planet, each of
which was characterised by a special population of animals and plants.
These successive populations were, he said, quite independent of each
other, and therefore the supernatural creative act, which was demanded
as the origin of the animals and plants by the dominant creed, must
have been repeated several times. In this way a whole series of
different creative periods must have succeeded each other; and in
connection with these he had to assume that stupendous revolutions or
cataclysms--something like the legendary deluge--must have taken place
repeatedly. Cuvier was all the more interested in these catastrophes
or cataclysms as geology was just beginning to assert itself, and
great progress was being made in our knowledge of the structure and
formation of the earth's crust. The various strata of the crust were
being carefully examined, especially by the famous geologist Werner
and his school, and the fossils found in them were being classified;