Can We Reduce Homology Across The Biological Hierarchy?

Several claims have been made to reduce homology at one level of the biological hierarchy to homology at a lower level. At a strict inquiry, all these claims reveal their epistemological weakness, for no reduction between homologies at different levels of the biological hierarchy can be done straightforwardly. The centrality of the ‘homology’ concept for biology makes this an interesting case-study in illustrating once more the gap between reductionism, as a broad research program, and actual reduction, a sa stringent epistemological work.