Pub. date: 2006 | Online Pub. Date: September 15, 2007 | DOI: 10.4135/9781412952453 | Print ISBN: 9780761930297 | Online ISBN: 9781412952453| Publisher:SAGE Publications, Inc.About this encyclopedia
Non-Darwinian Evolutionary Mechanisms
John R. Grehan
Charles Darwin was never entirely satisfied with the evolutionary role he originally gave to natural selection in On the Origin of Species . He later expressed reservations about attributing too much of evolution to the action of natural selection and survival of the fittest because he became convinced that nonfunctional structures evolving without natural selection could later prove to be useful and therefore come within the range of natural selection. Darwin thought his failure to sufficiently consider the existence of structures that are neither beneficial nor injurious was one of the greatest oversights in his work. He realized that he was not able to eliminate entirely the influence of his former belief that each species had been purposely created and each structure was of some special service. He felt that anyone with this assumption in mind would naturally extend the action of natural selection too far. Darwin's observation on the ...