Evolutietheorie: verschil tussen versies

Darwin gaf toe dat het onzinnig lijkt om aan te nemen dat het '''oog''' door natuurlijke teeltkeus is ontstaan: "''Te veronderstellen dat het oog – met al zijn weergaloze vernuftigheden om de scherpstelling aan te passen aan verschillende afstanden, om verschillende hoeveelheden licht toe te laten, om vorm- en kleurstoringen te corrigeren – door natuurlijke selectie gevormd kan zijn, lijkt, ik geeft het toe, absurd in de hoogste graad."''<ref>Uit: Charles Darwin, ''On the origins of species by means of nataralnatural selection or the preservation of favoured races in the struggle for life''" (New York: D. Appleton and company, 1861), blz. 167. De context met het aangehaalde citaat (onderstreept door Kees Langeveld) is deze: "''Organs of extreme perfection and complication.'' - <u>To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree</u>. Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if, further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself first originated; but I may remark that several facts make me suspect that an sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound."</ref>