Common descent and adaptation in On the Origin of Species

Abstract

In On the Origin of Species, natural selection is initially introduced as a resource for explaining the diversification of living forms from a common ancestor. Once it is acknowledged, it is possible to say that the main goal of the Theory of Natural Selection is not to provide an explanation for adaptation but to establish a mechanism that, being capable of generate diversification without contradicting the conditions of existence that all living beings must satisfy to be able to subsist, could support the Theory of common descent. Adaptationism must be considered a corollary of the theory that Darwin formulated to explain the descent with modifications. But this corollary, which initially brought obstacles for the theory, ended up by generating a productive research program that was developed simultaneously with another project, which aim was the reconstruction of the tree of life.