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Meeting Abstract
In the first edition of On the Origin of Species Darwin used what is known as “the metaphor of the wedges” to illustrate how competition between species might serve as a driving force for natural selection. A careful reading of Darwin’s notebooks, letters, manuscripts, and publications indicate that this striking image appears and disappears multiple times in the body of his writings from his geological descriptions through the transmutation notebooks and eventually to the Origin. I propose that the magnificent vistas of the Andes that Darwin viewed as he crossed the cordilleras during the Beagle expedition were the original inspiration for this imagery and that his experience there had a profound impact on his later work. Thus this metaphor represents an important link between Darwin’s early geological observations and his development of the theory of evolution by natural selection.