C. difficile diarrhea is largely a nosocomial disease and is the most frequent cause of diarrhea in hospitalized patients. Its occurrence in the outpatient setting, other than in patients confined to nursing homes, is much less common.
Darwin had arrived at a complete theory of evolution by 1839, but it was to be another 20 years before he published his ideas of evolution through natural selection in his epochal book On the Origin of Species by Means of Natural Selection.
Charles Darwin. Charles Darwin, widely considered as one of the greatest and most revolutionizing scientists in history, was the British naturalist who formulated the theory of evolution. Pre-Darwin, it was thought that each species of life on earth came individually and that none had ever changed its form.