Primera aproximación estructuralista a la teoría del origen en común

This paper is a first approach (from the structuralist view of scientific theories) to the Theory of Common Descent (TCD) as it appears in On the Origin of Species, by Charles Darwin. Firstly, we expose the difference between this theory and the theory of natural selection and the theory of evolution. Afterwards, some debates about the determination of homologies (the explanandum of TCD) are presented. The same is done regarding the vocabulary and the fundamental law of the theory. Lasltly, we start the identification of the TOC-theoretical terms and of some specializations (taking into account new theoretical elements that were incorporated after 1859)