The Cuvier theory of evolution, also known as the Catastrophism theory, is a scientific explanation that explains how catastrophic events have shaped the evolution of life on earth. This theory was proposed by the French naturalist Georges Cuvier in the 19th century.
What is Catastrophism Theory?
According to Catastrophism, the Earth has been subjected to several catastrophic events that have brought about widespread destruction of life forms. These events could be anything from floods, volcanic eruptions, earthquakes or even asteroid impacts. Cuvier believed that these events were responsible for mass extinctions of species and led to new forms of life.
How does it differ from other theories?
Catastrophism differs from other theories such as Uniformitarianism which suggests that slow and gradual processes like erosion and weathering were responsible for shaping the Earth’s surface. Catastrophists believe that sudden and violent events have played a more significant role in shaping our planet.
The Five Major Extinctions
Cuvier identified five major extinctions in his theory, each one being caused by a catastrophic event. The first extinction wiped out marine invertebrates (animals without backbones) and happened during the Ordovician period. The second extinction took place during the Devonian period, wiping out most marine species.
The third extinction occurred at the end of the Permian period where almost all species on land and sea disappeared due to volcanic activity. The fourth was during the Triassic period where most large amphibians were wiped out, possibly due to asteroid impact.
Finally, the fifth extinction occurred at the end of the Cretaceous period when dinosaurs vanished after a massive asteroid impact.
Impact on Evolutionary Biology
Catastrophism had a significant impact on evolutionary biology as it challenged earlier beliefs that species were immutable and unchanging. Cuvier believed that each catastrophic event created a new set of conditions that would select for certain traits in organisms, leading to the emergence of new species.
While Catastrophism theory is not widely accepted today, it was an important contribution to our understanding of how life has evolved on Earth. It helped scientists to recognize the role of catastrophic events in shaping the planet and provided a framework for studying the history of life on Earth.