Challenging Darwin and why we are all fat.

In  the broadest terms,  theories of evolution seek to explain why species are the ways they are. For many evolutionists, this means explaining the possession by species of characteristic adaptations. It also means explaining diversity within species

 

The evolutionary psychologist (e.g. Tooby and Cosmides 1992) tends to assume that the most important inheritance mechanism in all species—our own included—is genetic inheritance.

Evolutionary psychology regards the human mind as evolving through a conventional process of natural selection acting on genetically inherited variation. For example, an evolutionary psychologist might explain the widespread taste among humans for fatty foods in terms of the importance in our species' distant past of consuming as much fat as possible on those rare occasions when the circumstances presented themselves.

 Such a hypothesis  can also help to explain novel cultural trends: the recent increase in obesity is explained as the result of a novel environmental change—the increased availability of cheap, high-fat foods—acting in concert with a once-adaptive, (while we were on the Savannah) now dangerous, gustatory (taste)  preference.

 

Post Darwin oblique transmission

Darwin believed, as do biologists today, that natural selection can explain the origin of many complex adaptive traits

But we do not learn only from our parents—we also learn from peers, authority-figures and so forth. This is known as oblique transmission.

The admittance of oblique transmission into evolutionary theory necessitates far more radical revisions to traditional Darwinian models of evolution. This is because oblique transmission opens up the possibility that some traits may spread through a population in spite of the fact that they reduce the fitness of the individuals who bear them.

 

Prestige Bias

Boyd and Richerson suggest that prestige bias can overcome this problem: if individuals copy techniques from those who are in prestigious positions,(Television 'personalities' for instance)  then this increases the chances that they will copy techniques that are, in fact, beneficial. As they put it, ‘Determining who is a success is much easier than determining how to be a success.

Pass me that Hamburger and French fries. (joke)

 

Source Stanford Philosophy