Monday, October 19, 2009

How Physicists Always Get it Wrong

A few months ago, Nature Physics published an article about an eventual overthrow of evolutionary theory. It's seen often enough - and in different fields. Sometimes there is legitimate grounds for strong skepticism, sometimes it's contrarianism masquerading as skepticism and often, as in the aforementioned publication, it's a case of experts speaking outside their expertise (something we do at the Bayblab quite often). In a humourous paper entitled "A Simple Model of the Evolution of Simple Models of Evolution" [free pdf] the authors explain how it can happen, using an explosion of evolutionary models made by physicists as an example:

The question presents itself: why are we being deluged with such models? In the spirit of the field, we present a simple evolutionary model of this process.

  1. A physicist runs across or concocts from whole cloth a mathematical model which is simple, neat, and contains a great many variables of the same sort.

  2. The physicists has heard of Darwin (1859), and may even have read Dawkins (1985) or some essays by Gould, but wouldn’t know Fisher (1958), Haldane (1932) and Wright (1986) from the Three Magi, and doesn’t dream that such a subject as mathematical evolutionary biology exists.

  3. The physicist is aware that lots of other physicists are interested in annexing biology as a province of statistical physics.

  4. The physicist interprets his multitude of variables as species or (if slightly more sophisticated) as genotypes, and proclaims that he has found “Darwin’s Equations” (cf. Bak et al. (1994)), or, more modestly, has made an important step towards eventually finding those equations.

  5. His paper is submitted for review to other physicists, who are just as ignorant of biology as he, but see that it’s about equivalent to the other papers on evolution by physicists. They publish it.

  6. The paper is read by other physicists, because at least it’s not another derivation of specific heats on some convoluted lattice under a Hamiltonian named for some Central European worthy now otherwise totally forgotten. Said physicists think this is cutting-edge evolutionary theory.

  7. Some of those physicists will know or discover simple, neat models with lots of variables of the same type.

They continue:
[O]ur model predicts that simple statistical-physical models of evolution will continue to proliferate until either (a) all the available models are exhausted, or (b) they become as common and as boring as any other subject in the statistical physics literature, or (c) physicists learn some actual biology. We are not entirely confident that the third limiting factor will become operational before the others.
So there you have it: this will continue to be a problem until everybody learns more biology.

Of course, as much as we would like to think so, this isn't limited to physicists, even if they aren't as humble as us bio-types. And it's really just an extension of what we often lament in science writing (and other journalism) - poor understanding of the subject and headline grabbing, like the title of this post.


Anonymous Coward said...

Great post!

Rob said...

Interesting. However it sounds as if biologists think that their knowledge somehow evades a mathematical description.
It definitely does not.
Check out this article on the discovery of a NOVEL cellular pathway based entirely on math that I don't understand.

Anonymous said...

Rob, where do you get that idea?

Point #2: "...and doesn’t dream that such a subject as mathematical evolutionary biology exists."

Clearly biologists are aware that math applies.

Rob said...

I grossly misread that post.
I read physics/math and then biology and was looking for an excuse to post that link.