what is lamarkism? and mutational theory of hugo de Vries?
Answers
De Vries held that new species arrive suddenly and without prior precedent through the process of mutation, which he considered to be the change of one species into another due to the formation of “a new center of analogous variations.” Rather than simply argue that species are discontinuous from each other—as in the case of neo-Lamarckism—mutation theory suggested that variations themselves are discontinuous, as in the cases of dwarfism, giantism, and albinism. Based on his observations of common evening primrose (Oenothera lamarckiana), which occasionally spawns offspring that differ significantly in leaf traits and overall size from parent generations and that sometimes cannot be crossed with parent generations, de Vries argued that new species came into existence fully formed and viable but lacking the defining characteristics of the parent generation. Thus, de Vries’s analysis focused on the creative force of discontinuity as a prime explanation for the origin of new species.