The explanatory role of natural selection is one of the long-term debates in evolutionary biology. Nevertheless, the consensus has been slippery because conceptual confusions and the absence of a unified, formal causal model that integrates different explanatory scopes of natural selection. In this study we attempt to examine two questions: (i) What can the theory of natural selection explain? and (ii) Is there a causal or explanatory model that integrates all natural selection explananda? For the first question, we argue that (...) five explananda have been assigned to the theory of natural selection and that four of them may be actually considered explananda of natural selection. For the second question, we claim that a probabilistic conception of causality and the statistical relevance concept of explanation are both good models for understanding the explanatory role of natural selection. We review the biological and philosophical disputes about the explanatory role of natural selection and formalize some explananda in probabilistic terms using classical results from population genetics. Most of these explananda have been discussed in philosophical terms but some of them have been mixed up and confused. We analyze and set the limits of these problems. (shrink)

An application of the entropic theory of perception to evolutionary systems indicates that environmental entropy increases will exert pressures on an organism to adapt. We speculate that the instability caused by such environmental changes will also cause an increase in the mutation rate of organisms leading to an eventual increase in their complexity. Such complexity generation allows organisms to adapt to the more entropic environment. Although we conclude that increases in environmental entropy cause an organism to evolve into a more (...) complex organism, increases in entropy may not be necessary for complexity generationper se. (shrink)