In this paper we discuss the epistemological positions of evolution theories. A sharp distinction is made between the theory that species evolved from common ancestors along specified lines of descent , and the theories intended as causal explanations of evolution . The theory of common descent permits a large number of predictions of new results that would be improbable without evolution. For instance, phylogenetic trees have been validated now; the observed order in fossils of new species discovered since Darwin's time (...) could be predicted from the theory of common descent; owing to the theory of common descent, the degrees of similarity and difference in newly discovered properties of more or less related species could be predicted. Such observations can be regarded as attempts to falsify the theory of common descent. We conclude that the theory of common descent is an easily-falsifiable & often-tested & still-not-falsified theory, which is the strongest predicate a theory in an empirical science can obtain. Theories intended as causal explanations of evolution can be falsified essentially, and Lamarck's theory has been falsified actually. Several elements of Darwin's theory have been modified or falsified: new versions of a theory of evolution by natural selection are now the leading scientific theories on evolution. We have argued that the theory of common descent and Darwinism are ordinary, falsifiable scientific theories. (shrink)

Geography has traditionally been assigned the role of handmaiden in evolutionary studies. In this work a different understanding of the relationship between biological change and locational setting is developed: evolution as a dynamic form of spatial interaction. In the causal model presented, adaptive change is portrayed as a negative feedback response contributing to a general spatial-temporal process of resource cycle tightening involving exchanges between the two fundamental structural sectors (abiotic and biotic) of the earth's surface system. As such, it is (...) rejected as evolution per se. This position makes it possible to circumvent the adaptation yields adaptation circularity, and to view locational circumstances as being evolutionarily causal, yet not deterministic with respect to population-level change. A parallel interpretation of the relation between range and range change and evolution is also implicit; the individualistic hypothesis is thereby superceded by a model of community evolution allowing for individualistic rates of population (adaptive and) range change, but operating on the principle that populations should tend to change range in common directions (as a response to spatially-varying degrees of efficiency of turnover of resources vital to biotic sector function). This in turn leads to the possibility of normative biogeographic modelling. Comment is also made on the relationship of the present understanding to disequilibrium and dynamic equilibrium interpretations of evolutionary change, and to human cultural evolution. (shrink)

The article gives an account of life and work of Jakob von Uexk?ll, together with a description of his impact to theoretical biology, behavioural studies, and semiotics. It includes the complete bibliography of Uexk?ll's published works, as well as an extensive list of publications about him.