History
Introduction
In this article we will find out how various scientists from different eras have hypothesized the theory of the evolution of living species.
Ancient Greece
Our journey begins in Greece, more than 2000 years ago. Many thinkers and philosophers of the time hypothesized that all living species come from a common ancestor, thus laying the foundations for the search for truth. However, Aristotle creates the concept of fixism, that is, believing in the theory of evolution given by the bible.
The Church and the Medieval Age
With the advent of Christianity, the Church prevented any research that could lead to the discovery of the reality of the facts, this because it would certainly have questioned the belief of its faithful in the doctrine professed by it. Research began in the mid-1700s, thanks to the trust that people were giving to the discovery of science and progress, thus pushing some naturalists and scholars to challenge the Holy See, formulating ideas about the age of the Earth and the relationships between organisms.
Lamarck and the first idea
In 1809, the biologist Jean-Baptiste de Lamarck published in his Philosophie zoologique the first coherent model of evolution, according to which the transmission to subsequent generations of traits acquired through the use and disuse of body parts was envisaged. This theory, however, was not exact and in fact, his theory will be disproved. The main reasons why this idea of evolution is wrong are 3:
- The characters are transmitted in the generations in the populations and not from the single individuals;
- Evolution is not directed to an end, therefore it does not lead to perfectly suitable organisms;
- The natural section is a process that can act only on hereditary characteristics since today we know that the characteristics acquired in the life of an organism cannot be transmitted to the offspring and cannot spread;
Charles Darwin and his Trip
In 1859, the biologist Charles Darwin published his book in London called "The Origin of Species by Natural Selection"; in this work the thought of Lamarck will be taken up, even if Darwin did not know it, also correcting the errors made by this, thus defining the theory of evolution. But how did this come about? When he was 20, Darwin came into contact with a book by the geologist Charles Lyell (principles of Geology), which provided clues to a much more remote geological past than was thought at the time. The biologist was very impressed by this text because it was able to give strength to the theories that he had already hypothesized at a ripe old age. Around the same time, the scientist was sailing around the world to seek help and evidence for his research. According to Lyell's theories, the great geological transformations were the result of small and gradual changes still taking place, calling this principle actualism in the future. At the time there were no planes, so Darwin had to travel his 5-year journey on the brig Beagle, visiting various parts of the world. In this period he took a lot of tests to be able to verify his theories, such as fossils, insects, finches of different populations, turtle shells, animals and much more, thus maturing in him the belief that they all descended from a common ancestor. His main goal was to find champions who could help him in his research, not being disappointed. Important were the Galapagos Islands, where Darwin was able to find various different populations, such as the finches and the giant turtles. In the future he will describe this journey in his autobiography, defining it as the most important moment of his life and for humanity.