Begin with a turnip…

Design space? Selection pressure? Neither––or all of the above?

“The notion of order is inseparable from that causality, which is itself an order of dependence. … The ability of a living being to move itself, even though it be only to assimilate and grow, involves therefore the organization of heterogeneous parts of which it is composed. This is why one says of living bodies that they are organisms or that living matter is organic [organiseé]. The finalism of Aristotle is an attempt to give a reason for the very existence of this organization. … To explain heterogeneous parts by the same principles which explain homogeneous parts is to leave deliberately unexplained the heterogeneity of the heterogeneous. … “–– Étienne Gilson, From Aristotle to Darwin and Back Again (University of Notre Dame Press, 1984), pp. 3, 97.

Try this: extend your arm partly out, with the palm of your hand hanging facedown, like you stopped midway reaching for something, and hold that pose. Now try extending (i.e., lifting up) each finger one by one without moving any of the others: thumb, pointer, “bird”, etc. Or try this: make a loos Black-Power fist, and try extending each finger one by one. What did you notice? Only the ring finger was hard to manipulate, right? Your ring finger kept “pulling” up a nearby finger, and it gave you an awkward tingle in the tendons of your wrist, right? (If I’m wrong, stop reading and go to your room!)

I mention this not as some kind of crude refutation of Berkeley’s idealism, nor as a demonstration of mind-body interaction and the freedom of the will, but as an entry point into considering the standard Darwinian method of explaining current human anatomy and physiology. I will focus on what I see as twin parameters in the Darwinian method: selective pressure (based, of course, on reproductive advantage) and design-space constraints. I hope this reflection will raise interesting questions about the enduring role of teleology in the Darwinian method as it aims to be a coherent explanation of the natural order.
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