Fact, Theory, and Rhetoric Evolution is the heart of all biology. Contemplate an organism. A biologist will answer that this complexity is the result of evolution.
Evolution is an observational fact of nature.
All life on earth is genealogically related in a great tree. We also have a theory, natural selection, to explain how evolution occurs. But much of what has been said about evolution includes lots of added rhetorical statements about what it all means. Conversely, one can find rhetorical statements about how nature is random and contingent, and that humans are nothing special in the universe. First, all the patterns we observe in nature point towards a nearly four billion year long history of evolution of life on earth.