Charles Robert Darwin

Charles Robert Darwin (1809 - 1882)revolutionized the life sciences with the publication of the "The Origin of Species" in 1859. He had a distinguished scientific ancestry: his grandfather, Eramus, proposed that all species evolved from a common source, and his father, Robert, was a physician who conducted experiments on the visibility of afterimages. Charles provided the evidence for a mechanism to account for evolution. The theory built upon the fact variability in all organisms. Some variations can affect the fitness for survival and reproduction, particularly in the event of any environmental changes. Those individuals that are better fitted to new conditions will have a greater chance of producing offspring, a process of natural selection that was not considered to be purposive. "This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest". He pursued the consequences of those ideas to human behavior, particularly in 'The Descent of Man' (1871) and in 'The Expression of the Emotions in Man and Animals (1872), thus laying the foundation for comparative psychology. In the former he argued that the rudiments of human mental processes are evident in animals, and in the latter he noted the similarity of human facial expressions and gestures to those of animals. Darwin also stressed the universality of emotional expression in human groups. - page 57