The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the (...) significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle. (shrink)

The Darwinian revolution supposed and imposed a much broader and more complex concept of environment than that which, until that moment, had been considered by most as part of natural history. Until Darwin, the environment of living beings had been regarded, almost exclusively, as the inanimate surroundings. This pre-Darwinian notion of environment included physicochemical and climatic variables: the living beings themselves were scarcely considered, or they were regarded just as food to be assimilated. In contrast, with Darwin, the influence of (...) living surroundings began to be regarded as having decisive importance for understanding the distribution, configuration, and viability of living beings. The relationships established among different living beings became the main and more significant features of the biological environment. This conceptual change was an exigency derived from the formulation and justification of the theory of natural selection. The idea of struggle for existence supposed by that theory requires that the biotic environment be considered critical in determining the viability of each living being. (shrink)

The main cognitive target of Ecology is the functional analysis of the ecological processes and systems. It does not suppose, meanwhile, that these processes and systems are designed systems and processes like individual leaving beings. The Ecology, likewise Physiology, is constitutively guided by the presupposition of a privileged state , to be explained, that it is the persistence of the systems and processes that she studied; and its functional analyses obey to this presupposition. Ecology supposes an ideal of natural order (...) , under which consideration this privileged state is thinking as an improbable state of things and, for that, needed of explanation; and, in what concerns this latter point, the analogy between Ecology and Physiology can also result instructive. DOI:10.5007/1808-1711.2010v14n3p349. (shrink)