In his theory of evolution, Darwin implied that

Charles Darwin's theory of evolution suggests that the most successful organisms are those that best adapt to their environment. He proposed that living organisms compete with each other for resources, such as food, water, and shelter. Organisms with traits that make them better suited to their environment are more likely to survive and reproduce, passing on their advantageous traits to their offspring. This process, called natural selection, leads to the gradual change and evolution of species over time. Darwin did not suggest that the struggle for existence among living organisms is sporadic or that organs of the body which are not regularly used by an organism will disappear. He also did not believe that any traits acquired by an organism during its lifetime could be passed on to its offspring, as those traits would not be encoded in the organism's genes.