Charles Darwin is known as the father of evolution due to his contribution to the establishment of the theory of evolution. His theory helped remove all the conventional old believes which said that the formation of various species was a supernatural phenomenon or act of the Almighty. Darwin’s evolutionary theory of natural selection gave a more rational explanation of the formation of new species. As per natural selection, various species originated from a single species as a result of adaptation to the changing environment.
Darwin had the following ideas regarding the theory of natural selection:
- Species keep on evolving or changing with time. As the environment changes, the needs of an organism also change and they adjust as per the new environment. This phenomenon of changing over a period of time as per the natural requirements is called adaptation. As per Darwin’s theory, only the superior changes are naturally selected and the inferior ones are eliminated. Thus, not all the adaptations contribute to a progressive evolution. For example, people living in tropical countries have more melanin in their body to protect them from the sunlight.
- Almost all organisms share common ancestry with some organism. According to Darwin, all organisms had one common ancestor at some point in time and kept on diverging ever since. His evolutionary theories support the convergent theory and divergent theory of evolution with examples. He had studied the birds at Galapagos Island which were later called Darwin’s finches. These birds developed different beaks as per the food availability. This showed adaptive radiation. Similarly, he also observed the Australian Marsupials which showed a number of marsupials emerging from an ancestor.
- According to Charles Darwin, evolution is a very slow and gradual process. He believed that evolution took place over a very long period of time. When we talk about the time period in evolution we usually refer to billions of years. The generation of a species from another takes a long period of time. It is a very steady process as the changes and adaptation take a long time to stabilize and give rise to a new species.
Natural selection takes place in four different ways as follows:
- Variation – The changes accumulated over a period of time in an organism usually gives rise to a new species.
- Inheritance – It is the passing on of the variations over generations which ultimately leads to speciation.
- A high rate of growth of population – This gives rise to more number of organisms being reproduced by a species than the environment can support which might lead to the extinction of that particular species.
- Differential survival and reproduction – The superior variations lead to survival of a particular organism and the inferior or negative variation leads to extinction. The superior variations are the ones inherited during reproduction.
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