Specululation Quotes (1 quote)
We are as remote from adequate explanation of the nature and causes of mechanical evolution of the hard parts of animals as we were when Aristotle first speculated on this subject … I think it is possible that we may never fathom all the causes of mechanical evolution or of the origin of new mechanical characters, but shall have to remain content with observing the modes of mechanical evolution, just as embryologists and geneticists are observing the modes of development, from the fertilized ovum to the mature individual, without in the least understanding either the cause or the nature of the process of development which goes on under their eyes every day
From 'Orthogenesis as observed from paleontological evidence beginning in the year 1889', American Naturalist (1922) 56, 141-142. As quoted and cited in 'G.G. Simpson, Paleontology, and the Modern Synthesis', collected in Ernst Mayr, William B. Provine (eds.), The Evolutionary Synthesis: Perspectives on the Unification of Biology (1998), 171.