Today marks the 200th birthday of Charles Darwin (February 12, 1809 - April 19, 1882), perhaps the ultimate FreeThoughtAction hero.
According to Wikipedia, Darwin "was an eminent English naturalist who achieved lasting fame by convincing the scientific community that species develop over time from a common origin. His theories explaining this phenomenon through natural and sexual selection are central to the modern understanding of evolution as the unifying theory of the life sciences, essential in biology and important in other disciplines such as anthropology, psychology and philosophy."
Darwin's 1859 publication of On the Origin of Species and his 1871 The Descent of Man not only unified the life sciences, it revolutionized human thought, overturning the argument from design (or teleological argument), that had prevailed for thousands of years.
See:
Seven signs of evolution in action
Darwin still making waves 200 years later
Evolve your plans to mark Darwin's 200th
Happy 200th Darwin Day!
Heat The Hornet
Why Evolution Is True
Your Inner Fish