Proximal vs ultimate constraints on evolution

For a mathematician — like John D. Cook, for example — objectives and constraints are duals of each other. But sometimes the objectives are easier to see than the constraints. This is certainly the case for evolution. Here, most students would point you to fitness as the objective to be maximized. And at least at a heuristic level — under a sufficiently nuanced definition of fitness — biologists would agree. So let’s take the objective as known.

This leaves us with the harder to see constraints.

Ever since the microscope, biologists have been expert at studying the hard to see. So, of course — as an editor at Proceedings of the Royal Society: B reminded me — they have looked at constraints on evolution. In particular, departures from an expected evolutionary equilibrium is where biologists see constraints on evolution. An evolutionary constraint is anything that prevents a population from being at a fitness peak.

Winding path in a hard semi-smooth landscape

In this post, I want to follow a bit of a winding path. First, I’ll appeal to Mayr’s ultimate-proximate distinction as a motivation for why biologists care about evolutionary constraints. Second, I’ll introduce the constraints on evolution that have been already studied, and argue that these are mostly proximal constraints. Third, I’ll introduce the notion of ultimate constraints and interpret my work on the computational complexity of evolutionary equilibria as an ultimate constraint. Finally, I’ll point at a particularly important consequence of the computational constraint of evolution: the possibility of open-ended evolution.

In a way, this post can be read as an overview of the change in focus between Kaznatcheev (2013) and (2018).
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Unity of knowing and doing in education and society

Traditionally, knowledge is separated from activity and passed down from teacher to student as disembodied information. For John Dewey, this tradition reinforces the false dichotomy between knowing and doing. A dichotomy that is socially destructive, and philosophically erroneous.

I largely agree with the above. The best experiences I’ve had of learning was through self-guided discovery of wanting to solve a problem. This is, for example, one of the best ways to learn to program, or math, or language, or writing, or nearly anything else. But in what way is this ‘doing’? Usually, ‘doing’ has a corporal physicality to it. Thinking happens while you sit at your desk: in fact, you might as well be disembodied. Doing happens elsewhere and requires your body.

In this post, I want to briefly discuss the knowing-doing dichotomy. In particular, I’ll stress the importance of social embodying rather than the physical embodying of ‘doing’. I’ll close with some vague speculations on the origins of this dichotomy and a dangling thread about how this might connect to the origins of science.

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John Maynard Smith on reductive vs effective thinking about evolution

“The logic of animal conflict” — a 1973 paper by Maynard Smith and Price — is usually taken as the starting for evolutionary game theory. And as far as I am an evolutionary game theorists, it influences my thinking. Most recently, this thinking has led me to the conclusion that there are two difference conceptions of evolutionary games possible: reductive vs. effective. However, I don’t think that this would have come as much of a surprise to Maynard Smith and Price. In fact, the two men embodied the two different ways of thinking that underlay my two interpretations.

I was recently reminded of this when Aakash Pandey shared a Web of Stories interview with John Maynard Smith. This is a 4 minute snippet of a long interview with Maynard Smith. In the snippet, he starts with a discussion of the Price equation (or Price’s theorem, if you want to have that debate) but quickly digresses to a discussion of the two kinds of mathematical theories that can be made in science. He identifies himself with the reductive view and Price with the effective. I recommend watching the whole video, although I’ll quote relavent passages below.

In this post, I’ll present Maynard Smith’s distinction on the two types of thinking in evolutionary models. But I will do this in my own terminology to stress the connections to my recent work on evolutionary games. However, I don’t think this distinction is limited to evolutionary game theory. As Maynard Smith suggests in the video, it extends to all of evolutionary biology and maybe scientific modelling more generally.

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Heuristic models as inspiration-for and falsifiers-of abstractions

Last month, I blogged about abstraction and lamented that abstract models are lacking in biology. Here, I want to return to this.

What isn’t lacking in biology — and what I also work on — is simulation and heuristic models. These can seem abstract in the colloquial sense but are not very abstract for a computer scientist. They are usually more idealizations than abstractions. And even if all I care about is abstract models — which I can reasonably be accused of at times — then heuristic models should still be important to me. Heuristics help abstractions in two ways: portfolios of heuristic models can inspire abstractions, and single heuristic models can falsify abstractions.

In this post, I want to briefly discuss these two uses for heuristic models. In the process, I will try to make it a bit more clear as to what I mean by a heuristic model. I will do this with metaphors. So I’ll produce a heuristic model of heuristic models. And I’ll use spatial structure and the evolution of cooperation as a case study.

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As a scientist, don’t speak to the public. Listen to the public.

There is a lot of advice written out there for aspiring science writers and bloggers. And as someone who writes science and about science, I read through this at times. The most common trend I see in this advice is to make your writing personal and to tell a story, with all the drama and plot-twists of a good page-turner. This is solid advise for good writing, one that we shouldn’t restrict to writing about science but also for writing the articles that are science. That would make reading and writing as a scientist (two of our biggest activities) much less boring. Yet we don’t do this. More importantly, we put up with reading hundreds of poorly written, boring papers.

So if scientists put up with awful writing, why do we have to write better for the public? I think that the answer to this reveals something very important the role of science in society; who science serves and who it doesn’t. This affects how we should be thinking about activities like ‘science outreach’.

In this post, I want to put together some thoughts that have been going through my mind on funding, science and society. These are mostly half-baked and I am eager to be corrected. More importantly, I am hoping that this encourages you, dear reader, to share any thoughts that this discussion sparks.

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