Charles Robert Darwin FRS (12 February 1809 – 19 April 1882) was an English naturalist who realised and demonstrated that all species of life have evolved over time from common ancestors through the process he called natural selection. The fact that evolution occurs became accepted by the scientific community and much of the general public in his lifetime, while his theory of natural selection came to be widely seen as the primary explanation of the process of evolution in the 1930s,and now forms the basis of modern evolutionary theory. In modified form, Darwin’s scientific discovery is the unifying theory of the life sciences, providing logical explanation for the diversity of life.