Notwithstanding the quasi-religious enthusiasms of ultra-Darwinists, their own understanding of theology is a combination of ignorance and derision, … - Simon Conway Morris

The fact that we arrived here via an immensely long string of species that originated in something like Pikaia rather than some other crepuscular blob is a wonderful scientific story, but it is hardly material to our present condition.

... not only that, but it can instruct us as to what may be the limits of desirable knowledge and risks of unbridled curiosity. This world-picture could also show that far from being a series of mindless accidents, history has directions and conceivably end-points.

The underlying reason for convergence seems to be that all organisms are under constant scrutiny of natural selection and are also subject to the constraints of the physical and chemical factors that severely limit the action of all inhabitants of the biosphere. Put simply, convergence shows that in a real world not all things are possible.