Original paper

Darwin's Origin as a modern theory

Reif, Wolf-Ernst


The structure of the modern theory of evolution is controversial in biology and in the philosophy of science. Classical texts often carry common-sensical characteristics, but these are rarely analyzed. Here, I give a full interpretation of the first edition of Charles Darwin's "On the Origin of Species" (1859). I propose that today, the term "evolution" is used with three different meanings which are not clearly separated in the technical literature and in text-books: Evolution I is the irreversible process of the historical change of the biosphere from the first bacteria to the present (= phylogeny). It is a simple truth that this process takes place. However, details of the process (velocity, gradualness) have been controversial up to the present day. Evolution II encompasses the causal factors that control evolution (mutation, recombination, natural selection etc.). Evolution III is the historical narrative of the history of the biosphere. All processes in Evolution III are explained by previous events, contingencies, etc. Darwin's goal was to demonstrate the truth of evolution I and its special features and to find factors (evolution II) that control this process (mainly: natural selection.)Darwin regarded the theory of descent and the theory of natural selection as a single theory. History has shown that these are two different theories. He worked with different methodologies, mainly analogy and hermeneutics. (1) Analogy is used in two different important contexts: (a) variability and all different phenomena of inheritance in domestic breeding are seen as analogies of variability and inheritance in the wild, (b) natural selection in domestication is seen analogy to natural selection. Darwin gives no justification for these analogies. They are simply a-priories. (2) Hermeneutic circles (reciprocal illumination) are common in the book such as: (a) I learn from geological theories of the fossil record for the understanding of the distribution of fossils and vice versa, (b) I learn for theories of descent and natural selection from the small scale distribution of species and ecology and vice versa, and (c) I learn for biogeography from physical mechanisms of dispersal and vice versa. Darwin worked for twenty years to develop his theory. It is hence not surprising that he omitted aspects of which he was only unconsciously aware or which were self-evident for him. I try to clarify the contexts where Darwin made indications between the lines. For instance, he had a highly complex organism-concept, which characterised the organism in the ecological game from conception to death and acquiring new heritable variability. The title of the book "On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life" is Darwin's research programme, namely the behaviour of species and populations in the ecological game; the origin of new species from older ones by splitting and transformation; the acquisition of new characters in species populations etc. Struggle for existence and natural selection are ecological processes of high importance. Nevertheless it is hardly stated in the literature that Darwin regarded evolution from the point of view of an ecologist. It is commonly stated that he had neither an understanding of genetics, nor of the process of speciation. I show that both criticisms are wrong, and that Darwin could hardly have solved his task if he had not collected all possible data from breeders and if he had not developed a very complex model of speciation from his non-arbitrary, non-pragmatic species concept.Careful reading of the "Origin" reveals that the book has a very modern basis of ecology, genetics, species concept and speciation model. In addition Darwin laid the basis for a handful new biological, geographic and geological disciplines which had not even received a name in Darwin's times: Transmission genetics, population genetics, developmental genetics, evolutionary ethology, evolutionary ecology, evolutionary morphology, evolutionary embryology, and ecology of eco systems. In contemporary philosophy of science theories are bodies of data, laws and hypotheses that allow predictions and explanations within a certain empirical field. "Modern theory" is no established term. I use it here to demonstrate that Darwin exhaustively showed connections between all his empirical data, developed laws, predictions and explanations, and carefully observed Ockham's Razor. This formed the basis of theoretical evolutionary biology and the development of a significant number of sub-disciplines.


ecologyevolutionary theoryhermeneuticsmodern synthesisspeciationspecies concepttypologyvariation