Spór o darwinizm

Abstract

CHALLENGES TO DARWINIAN THEORY Summary The two main points of the neodarwinian theory of evolution are: (I) that evolution results interaction between environment, organisms, and various evolutionary forces (natural selection, genetic drift, mutation pressure), among which natural selection plays the dominant role under the majority of normally encountered conditions; and (II) that macroevolutionary patterns also are a product of the same interaction, but extended over vast time spans and huge numbers of species. Molecular biologists, however, have recently discovered many mechanisms that add to the list of evolutionary forces and thus require a modification of the theory. Paleontologic and systematic challenges to the neodarwinian theory have thus far been less successful. Punctuated equilibrium may describe patterns of phenotypic evolution as revealed by the fossil record, but it does not force biologists to accept anything new about evolution. The same conclusion holds for mass extinctions and cladistics. The theory of diversity dependent diversification and the theory of species election and its extension into the hierarchical theory of selection, in turn, describe evolutionary forces that may potentially exist. Their real operation in nature, however, still remains unproven. Their acceptance or rejection depend therefore on methodological options.