The belief that God had created mankind in his own image and likeness was shared by most western scientists until the middle of the 19th century They thought all the creatures of the planet had been conceived by a divine force That is, until Charles Darwin arrived Some researchers were already talking about an evolution of the species, but the British naturalist was the first to to explain, with evidence, how evolution might occur Natural selection His theory radically changed biology, offering a new explanation of the origin of human beings It also made him one of most influential scientists and intellectuals in History But to get there, he had to make an extraordinary journey, Perform hundreds of experiments and spend 20 years refining his ideas In 1831, Darwin was 22 years old and studying at the University of Cambridge, when he was invited, as a naturalist, to a great expedition He boarded the HMS Beagle and spent almost 5 years traveling several continents, Starting in South America, from which he brought back dozens of live specimens, illustrations and fossils. These fossils gave him one of the first clues about evolution Observing the remains of a Mylodon, he noticed it was similar to the sloth but far larger He thought that those similarities were probably not a coincidence. There had to be some kind of link between the ancient animal and the current one When he stopped at the Galapagos Islands, Darwin also observed its giant tortoises which lived in nearby islands, but showed unique physical characteristics in each island In the humid areas, where vegetation was abundant, the turtles had a short neck and a dome-shaped shell, whilst in the islands with an drier environment they had a saddle-like shell and a longer neck But could he explain that difference?
Upon his return, Darwin spent time observing how animal breeders and gardeners cross-bred animals of a species to create new varieties For that creation to be successful, the artificial selection made by man was key. Darwin realized that the natural world probably made the same kind of selection, but he couldn't explain how it happened . .
. Until he read the work of Thomas Robert Malthus, A British intellectual from the 18th century In an essay on demography, Malthus said that when the population in Europe was growing it would increase much more than the food supplies available. That would provoke A fight for survival.
This idea helped Darwin explain how evolution works In nature there is a struggle for survival, in which the strongest individual is not necessarily the survivor Instead, it is the one which best adapts to the environment where it lives. If a living being has any trait that helps him to survive, it will be more successful at reproduction; Those which don't adapt will die without descendants. The creatures with the most success in reproducing pass their traits to their lineage and so on, until these variations end up becoming a new species That's why the differences between the tortoises that Darwin saw in the Galapagos were a product of evolution In a drier environment, those with the long necks could reach the bushes easily in order to get food whilst those who lived in the humid environment could eat grass and protect themselves from predators thanks to the shorter neck and to the dome-shaped shell Darwin said that all species, including humans, were not created independently but they descended from a common ancestor From then on, life on the planet began to diversify Twenty years after his trip on the Beagle, Darwin had written thousands of pages but he hadn't published any.
He wanted to have irrefutable evidence, perhaps because he knew that his theory was going to cause quite a stir But everything changed when he received a letter from Alfred Russell Wallace, an admirer and fellow naturalist who told him that he had reached the same conclusion: that evolution was produced by natural selection Darwin panicked facing the possibility that Wallace could take sole credit for the theory The two naturalists agreed to present A joint letter explaining their findings But a year later Darwin published his book titled "On the origin of species", and he became a celebrity way beyond the scientific community His findings shook the foundations of Victorian Britain Just like Copernicus in the 16th century, Darwin changed the game, by explaining that the diversity of the world came from a biological process, without any interference from God Darwin put the human beings in the same evolutionary level as all the creatures on the planet Scientific advancesÊ have confirmed his theory and even the Catholic Church ended up accepting, decades later and with conditions, that evolution iscompatible with faith And today, more than 150 years after the world was introduced to Darwin's theory, We see evolution as fact. The planet keeps changing, Sometimes dramatically. And we.
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