[[Image:Feather image.jpg|thumb|300px|right|[[Harvard]] biologist [[Ernst Mayr]] wrote: "It must be admitted, however, that it is a considerable strain on one’s credulity to assume that finely balanced systems such as certain sense organs (the eye of vertebrates, or the bird’s feather) could be improved by random [[mutation]]s."<ref>[http://www.creationscience.com/onlinebook/ReferencesandNotes9.html Ernst Mayr, Systematics and the Origin of Species (New York: Dover Publications, 1942), p. 296]</ref>]] | [[Image:Feather image.jpg|thumb|300px|right|[[Harvard]] biologist [[Ernst Mayr]] wrote: "It must be admitted, however, that it is a considerable strain on one’s credulity to assume that finely balanced systems such as certain sense organs (the eye of vertebrates, or the bird’s feather) could be improved by random [[mutation]]s."<ref>[http://www.creationscience.com/onlinebook/ReferencesandNotes9.html Ernst Mayr, Systematics and the Origin of Species (New York: Dover Publications, 1942), p. 296]</ref>]] |