PSYCH 3T03 Chapter Notes - Chapter 1: Medium Ground Finch, Character Displacement, Daphne Major
13 Apr 2018
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Document Summary
Competitor species can cause a divergence in resource-exploiting traits amongst each other (i. e. character displacement) This article provides details of the rst investigation of character displacement (from the initial encounter to the resulting directional selection) and evidence for the role of competition in models of community assembly, speciation, and adaptive radiations. A darwin"s nch species (geospiza fortis) on an undisturbed gal pagos island diverged in beak size from a competitor species (g. magnirostris) 22 years after the competitor"s arrival. The medium ground nch of daphne major, due to the absence of the small ground nch and lack of competition, is unusually small in beak and body size. In 1997, a drought on daphne revealed that small seeds are usually preferred, but if scarce, nches turn to large, hard seeds that only large-beaked members can crack: mortality greatest among those with small beaks.
