Non morphologic characters and methods in Zoologic Systematics, especially those related with the isolating mechanisms

Abstract

The author describes the different characters and methods which are used, not to replace the morphological characters and methods which still are, for practical reasons, the basis of taxonomy, but to supplement them. The trend started in bacteriology where the morphological characters are especially few and unreliable: antigenic composition and enzymatic properties proved invaluable tools in the since cases of convergence are known, but they are so far restricted to carbohydrates. The biochemical methods have also been successfully applied to the plants and animals: chromatography, electrophoresis, salting, precipitine tests. Other characters are especially useful to detect the sibling species, which, by definition, are morphologically indistinguishable or almost indistinguishable. They are related to isolating mechanisms; seasonal isolation, habitat isolation, ethological isolation. Following Mayr's classification, the author mentions and exemplifies the visual stimuli, the chemical stimuli and the auditory stimuli. All insure the attraction between the sexes within their species, but prevent ipso facto any hybridation with related species.