Discussion summary by Magdalena Kozielska:

Today we discussed an influential paper by McNamara and Houston “Integrating function and mechanism” (Trends in Ecology & Evolution, (2009) 24:670-675).

In our group thinking about mechanisms is common place, but 10 years ago the paper was controversial. However, it also received awards and last sentence of the abstract was often quoted.

“Although behavioural ecologists have built complex models of optimal behaviour in simple environments, we argue that they need to focus on simple mechanisms that perform well in complex environments.”

As with Fawcett et al. (2012) one of the problems of the paper is that terms “mechanism” and “rule” are used interchangeably, while rules of behavior likely have physiological mechanisms (brain function) underlying them. Even if the rules might be simple, underlying mechanisms may be not.

Of course one has to decide on the level of complexity one is going to study, e.g. will it be brain function or behavioural rules. In our group we try to take an intermediate approach. Acknowledging that even our “mechanistic” approach may not be very realistic. Therefore, multiple approaches to understanding animal behavior (also advocated by MARM group) will likely bring a better understanding of their evolution.

Simple rules have few parameters and therefore few degrees of freedom and simple genotype-phenotype mapping. In our group we would like to study more complex mechanisms, with more degrees of freedom and more complex genotype-phenotype mapping through inclusion of genetic and neuronal networks.

Fawcett et al. (2012). Exposing the behavioral gambit: the evolution of learning and decision rules. Behavioral Ecology, 24:2-11.