Benji’s Reviews > Agents and Goals in Evolution > Status Update

Apparent anomalies of choice can often be eliminated by changing the state-space.

When arbitrary combinations of aggregate and idiosyncratic risk are considered, irrational risk preferences may evolve.

If number of offspring is replaced by wealth, mother nature behaves just like the rational investor described by Bernoulli, whose utility function is logarithmic in their wealth.

Although a version of Hamilton's rule is indeed a fully general evolutionary truth, nothing about individual maximization can be deduced directly from this generalized form of the rule, contrary to what is sometimes implied.

Adaptationism in biology must ultimately be justified on empirical rather than theoretical grounds. This conflicts with the widespread assumption that natural selection has an intrinsic tendency to produce adaptation, unless constraints or non-selective forces intrude.

The hill-climbing property obtains only in special cases, and the steepest ascent property yet more rarely; so they are not general properties of biological evolution. Wright himself was aware that average population fitness would not always increase, in particular where genotype fitnesses were not fixed; but he hoped an alternative quantity could be found that would be maximized by natural selection. Alas.

To the extent that agential thinking in evolutionary biology is justified, it is empirical facts about the world that justify it, and not some overarching theoretical principle about how natural selection works.

Treating an evolved organism as akin to an agent with a goal, and conceiving of its traits as means by which it tries to achieve its goal, does real work in biology; and where evolved behaviour is at issue, this fits naturally with making the organism the subject of intentional attributions.

The metaphor of agential choice is a problematic way of thinking about natural selection, as it only really makes sense where the selective environment is constant, and can easily mislead us into thinking that natural selection is inherently directional, mimics a goal-directed process, or leads to maximization of some quantity or other.

Rationality in folk psychology corresponds to optimality in evolutionary biology: they are both presuppositions of the respective modes of explanation. This parallel is deep and instructive. For notice that both modes of explanation have an irreducibly normative dimension.