Kant and the Natural Science of Organisms

Regarding the explanation of organisms as instances of complex design, Kantian philosophy faces a difficult problem: as material entities they should be explained through mechanical laws, but because of their design, they call for an explanation through final causes. Nonetheless, both explanations are unacceptable. Does Kant offer any way out? Part of his solution is that both teleology and mechanicism must apply as regulative principles. But this implies limiting mechanicism to a regulative idea, which is inconsistent with his claim that newtonian mechanics are a priori valid and constitutive of natural science and its objects. I inquire into Kant’s positive doctrine on the natural explanation of organisms, combining teleology and mechanicism, and into the way this fits in his natural philosophy