A few scientists before Georges Cuvier believed that fossils were the remains of species that no longer existed, but religion was still a powerful force in science in Cuvier’s time.
Many scientists could not believe that God would create living things only to wipe them out later.
Cuvier decided to settle the issue. For his research, he studied the bones of current-day elephants and the fossils of mammoths that had recently been found. Cuvier was the right man for the job because of his deep understanding of anatomy.
He could reconstruct entire skeletons from just a few key pieces.
Cuvier said his findings were indisputable. Not only was the mammoth a different species that no longer lived on Earth, but there were two different elephant species still on Earth, the African and Indian elephants.
He confirmed the theory by studying other mammal fossils like the Irish elk and the American mastodon. The fossils were the remains of animals that were extinct, or no longer on Earth.
The science of paleontology was born, but what had happened to these animals?
Cuvier made two assumptions to explain extinction.
The first was bold and correct: Earth was much older than previously thought. He did not come close to the age of 5 billion years we know today, but he was on the right track.
The second assumption was not so correct. He said conditions on Earth were much like the present throughout its very long history. However, once in a while, sudden and widespread catastrophes (Cuvier called them “revolutions”) would hit the planet and wipe out a number of species.
These catastrophes were natural events, like volcanoes, earthquakes, and floods, and they would also change Earth’s landscape. For this reason, he suggested that geologists study these events.
Geologists took Cuvier’s suggestion and studied Earth’s rock formations.
They found Cuvier’s theory of catastrophes, called catastrophism, to be basically wrong, mainly because Earth was much older than even Cuvier had guessed.
Geologists found that features of Earth changed slowly over long periods of time, they called it gradualism, also known as uniformitarianism.
Some recent findings have shown Cuvier’s theory to be correct sometimes, however. It is probable that the dinosaurs became extinct about 65 million years ago due to a giant meteor striking Earth.
The largest extinction in Earth’s history took place about 240 million years ago when about 96 percent of all species became extinct. Some evidence points to a meteor being responsible for that extinction also.
Cuvier was asked by Napoleon to become the naturalist on his expedition to Egypt in 1798. Cuvier refused, preferring his research at the Museum of Natural History.
Cuvier was the first to correctly propose that life in the sea preceded life on land and that reptiles preceded mammals.