The modern science of biology is based almost entirely upon the twin theories of Evolution and Natural Selection. We would not have the understanding we do of all aspects of the life sciences if it were not for the theories developed by this great thinker. In the past 150+ years, the details and the understanding of the underlying mechanisms have changed, but his basic premises remain sound.
February 12, 2013 is the 204th anniversary of his birth, and there are many events scheduled to promote his legacy and science in general.
Happy Birthday Charles.