Evolution is a biological process in which an organism changes to a different form which is usually more complex and sophisticated.
The process takes time (millions of years) and the changes are in response to the environment surrounding the organism.
The idea of evolution and evolutionary thought is very old and many biologists have done extensive research on the topic. However, it was in 1859 when English naturalist Charles Darwin published his now famous On the Origin of Species which brought the theory of evolution to the forefront.
Darwin in his theory of evolution argued that natural selection, struggle for survival and adapting to the environment drives evolution for every species.
The theory of evolution is a controversial idea till date and many religious organizations continue to oppose it.