Frases de Theodosius Dobzhansky

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Theodosius Dobzhansky

Data de nascimento: 25. Janeiro 1900
Data de falecimento: 18. Dezembro 1975
Outros nomes:Theodosius Grygorovych Dobzhansky

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Theodosius Hryhorovych Dobzhansky foi um geneticista e biólogo evolutivo ucraniano-estadunidense.

Dobzhansky nasceu na Ucrânia , iniciou os seus estudos na Universidade de Kiev e emigrou para os Estados Unidos em 1927.

Citações Theodosius Dobzhansky

„The greatest evolutionist of our century.“

— Theodosius Dobzhansky
Stephen Jay Gould, When a Fact Is Not a Fact; Awake! magazine, July 22, 1987.

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„According to Goldschmidt, all that evolution by the usual mutations—dubbed "micromutations"—can accomplish is to bring about "diversification strictly within species, usually, if not exclusively, for the sake of adaptation of the species to specific conditions within the area which it is able to occupy." New species, genera, and higher groups arise at once, by cataclysmic saltations—termed macromutations or systematic mutations—which bring about in one step a basic reconstruction of the whole organism. The role of natural selection in this process becomes "reduced to the simple alternative: immediate acceptance or rejection." A new form of life having been thus catapulted into being, the details of its structures and functions are subsequently adjusted by micromutation and selection. It is unnecessary to stress here that this theory virtually rejects evolution as this term is usually understood (to evolve means to unfold or to develop gradually), and that the systematic mutations it postulates have never been observed. It is possible to imagine a mutation so drastic that its product becomes a monster hurling itself beyond the confines of species, genus, family, or class. But in what Goldschmidt has called the "hopeful monster" the harmonious system, which any organism must necessarily possess, must be transformed at once into a radically different, but still sufficiently coherent, system to enable the monster to survive. The assumption that such a prodigy may, however rarely, walk the earth overtaxes one's credulity, even though it may be right that the existence of life in the cosmos is in itself an extremely improbable event.“

— Theodosius Dobzhansky
Genetics and the Origin of Species (1941) 2nd revised edition