ABSTRACT
There is an important sense in which biology as a science began only when Darwin hit upon the theory of natural selection in the late 1830s, although he did not publish the theory until 1859 (after A.R. Wallace hit upon it too, and threatened to scoop him). Of course there had been scientists making important discoveries about the biological world at least since Aristotle in the third century BC. In the 200 years prior to Darwin’s birth, Harvey and van Leeuwenhoek stand out for their discoveries that, respectively, the heart beats to circulate the blood and all living things are composed of cells. And there was Linnaeus’ system of classification of living things and his naming system for genus and species, the binomial nomenclature. But it can be argued that until Darwin’s achievement, none of these findings, explanations, or classifications could be organized into anything with a right to call itself a science. Darwin’s evolutionary theory explains more than just common descent, the shared ancestry of all organisms on Earth. It identifies a causal process that produces the adaptations we see everywhere in nature, one that replaces other accounts of the adaptation, other accounts that could not be causal or even in principle scientifically testable.
