Pharmacoepidemiology: a scientific basis for outcomes research

Publication: Ann Pharmacother
Division: Cognigen

The discovery of fossils estimated to be about 550 million years old’ and later, the interpretation of these fossils, forced a rethinking of Darwin’s theory of evolution. No longer is evolution thought to be a gradual process in which organisms move from being very simple to very complicated. A new theory, based on the analyses of these fossils, suggests that there was an explosion of life in the early Cambrian period, followed by a decimation of most species, and subsequent differentiation among the remaining stock

By Thaddeus H Grasela