Eimer

EIMER Gustav Theodor (Gustav Theodor Eimer), Tübingen zoologist, known for his research on the variation in pattern and coloration of wall lizards (Lacerta muralis) (1881) and butterflies (1897), on the basis of which he formulated the evolutionary theory, so-called 'orthogenesis.' Assigning together with Nägeli a secondary role to natural selection, Eimer recognized the growth of organisms beyond individuality as the main factor in evolution. This phyletic growth, stimulated by climate, food, etc., mainly depends on constitutional peculiarities, which is why variation occurs not in many directions, but only in one (directed evolution, or orthogenesis). On the basis of E.'s teaching, a number of other anti-Darwinian theories arose, for example, Berg's vitalistic teaching of nomogenesis, or evolution based on regularities. The most important works of E., published separately: 'Untersuchungen über das Variieren der Mauereidechse' (Berlin, 1881); 'Die Entstehung der Arten' (Jena, 1888); 'Artbildung und Verwandtschaft bei den Schmetterlingen' (Vol. 1-2 and Atlas, Jena, 1889-1895).