The History of Darwin’s Theory of Evolution

980 Words Jun 15th, 2018 4 Pages
Nothing in biology makes sense except in the light of evolution.
(Dobzhanski, 1973)

It was during his journey on board the Beagle that Darwin developed his theory of evolution. “On the Origin of Species” (Darwin, 1859) proposed two main principles: evolution really occurs and natural selection is its mechanism. This work published on 24th November 1859 traces a coherent portrait of life bringing together in an orderly manner an astonishing variety of apparently independent facts. It led biologists to concentrate on the diversity of organisms, their origins and their relation, their similarities and their differences, their geographical distribution and their adaptation to various environments.
Darwin (1859) arrived at two main
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The need for food fashions the animal model.
All which seem to have been gradually produced during many generations by the perpetual endeavour of the creatures to supply the want of food and to have been delivered to their posterity with constant improvement of them for the purposes required (Darwin, 1794-1796: section 39, “Of generations”).
Finally the need for safety intervenes specifically in the specific shaping of the legs which enables animals to be more adapted to flee.
However, this large visionary misses the mechanism which would make it possible to explain these adaptations.
Jean Baptiste Lamarck
Jean Baptiste Lamarck presented his theory on the transformation of species for the first time in 1800 in his “Discours d’Ouverture de l’an VIII”. He proposed:
The animals most imperfect, simply organized, those suspected in a world hardly endowed with animality, are perhaps those by which nature began when, with a lot of time and favourable circumstances, it has wrought all the other (Lamarck, 1801: 12).
For Lamarck, it was habits and environmental factors which influenced the evolution of the morphology of animals. With new shapes, new abilities are gained, and over time nature arrives to where it is now.
Charles Darwin
In 1831, Charles Darwin participated in a five year expedition on board the Beagle. Despite very little experience, he was offered the position of naturalist. During his travels, he studied a
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