On the defense of ‘Evolutionary and Newtonian Forces’

Dr. Ellen Clark, a.k.a. Philosomama, has written a good review of Velasco & Hitchcock’s Evolutionary and Newtonian Forces [no paywall], one of the first papers to appear in the new open access journal Ergo. She points out that although V&H are trying to show how evolutionary forces are well described by analogy to classical causal Newtonian forces, they very nearly prove their opponent’s — the statisticalist — position. However, she comes to their defense.

Briefly, the causalist position is that evolutionary forces are causal like the force of Newtonian gravity. Natural Selection is a causal force that acts on biological organisms. The statisticalist position claims evolutionary phenomena are just the statistical result of the underlying causal physical processes. Hence, for the statisticalist, evolutionary phenomena have no force of their own.

V&H want to argue that evolutionary forces are like friction or elasticity. Dr. Clark points out that these forces can be problematic for their view, as they too note:

As Velasco & Hitchcock acknowledge, friction and elasticity are usually thought of by physicists as emerging “from the aggregate statistical behaviour of more elementary forces in certain kinds of system.” … But this is grist to the statistical view’s mill, we might say. They argue that natural selection supervenes on more basic causal events, without adding any extra causal power of its own. So these critics might happily accept that evolutionary forces are analagous to non-fundamental Newtonian forces, whilst holding their ground on the claim that natural selection is not causal.

However, causalist vs. statistical isn’t what I would like to discuss here; see her review for more discussion. Instead I’d like to focus on her appeal to the unknown as a defense of V&H’s causalist position. She claims that it is OK to consider evolutionary forces causal, like Newtonian forces, because Newtonian forces are mysterious. Since Newtonian forces are mysterious, we shouldn’t privilege their causality and should grant that right to not well understood biological forces as well. She says:

If there is anything magical about thinking of natural selection as an overall force producing all the multifarious births and deaths that we actually observe, then it is in very good company lumped in with physical forces.

This is an example of my favorite fallacy, Ignotum Per Ignotius: explaining something unknown by appealing to something even less understood. Let me explain why this is really problematic for her defense and ultimately for V&H.

Imagine a statisticalist pointing to their analogies and explanations of evolutionary phenomena and saying, “Evolution isn’t mysterious at all, and we have a perfectly good statistical explanation right here. The only causality is in the underlying fundamental physics.” The evolutionary causalist is then in the uncomfortable luddite position of insisting, without reason, that we don’t understand evolution. Appealing to an analogy with physics that supports the causal position is question begging, if there is no deeper reason why this analogy holds other than it supports the claim that evolutionary phenomena are mysterious and hence causal. Therefore without some other reason to support the causal view of evolutionary phenomena, appealing to mysteriousness does not justify the causalist position.

Moreover, without a supporting causalist argument, V&H have done the statisticalist’s work for them. As noted above, they have gone and shown exactly how evolutionary phenomena are like statistical results of underlying forces.

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