Really good article Nate!

It's a profound dilemma...

Those people with less steep discount rates, and who are more capable of modifying their behaviour as a result of rational realisations are also those who tend to sacrifice themselves for the 'greater good' (by for example, not having children).

If there is a strong genetic component to discounting, this leaves the remaining population with progressively steeper discount rates, and thus less able to deal with the problems they face.

Beware with this evolutionary reasoning. Selection also happens on the level of the group, otherwise every trace of altruism would long have been eradicated from the gene pool.

Its still up for debate whether multilevel selection occured, though biologists now are developing (for monetary gain) cooperative shrimp, cooperative chickens, etc. that when raised in tight quarters do better (in total weight) than the 'selfish chickens'. Mike Wade and David Sloan Wilson are writing on this topic.

But altruism (in the truest sociobiologic sense termed reciprocal altruism), fits very well within a selfish gene framework of a social species. People 'do' altruistic acts, especially small ones, because their mind does not immediately do the payoff calculus, but in ancient times, living in small communities where everyone knew one another, helping, sharing and playing tit-for-tat had evolutionary advantages -so that altruism was a form of cooperation that had mutual benefits.

The modern world where people can pick up and move half a continent away and start over, sometimes short-circuits these altruistic tendencies, as oil at 18 cents a cup allows alot more people to 'cheat' this neural system designed for social give and take.

Though I dont want to derail this thread with a long debate with Ron Patterson ...;), I actually agree with you - that we did have historical bottlenecks where group selection was active - but still with individual selection at the core of long term evolution. But the majority of modern biologists, after George Williams blasted VC Lynne Edwards group selection hypotheses out of the water 30 years ago- conclusively do not believe in group selection (though it is making a comeback.)

I also think that genetic fitness is not only determined by the effects the genes have on their bearer, but also the possible offspring that they generate. In other words, the quality of the offspring is also a relevant factor in the selective pressures. A "perfect" genome is a lot less useful if a few slight mutations/interbreedings reduce the genebearers to crippled wrecks a generation or two hence. So there is more to the picture than meets the eye: a lot of influences are influencing natural selection, and we most likely don't know them all.
Applied to altruism, that could mean that completely selfish bastards are evolutionary maladapted: if they outcompete the others, a population will turn into selfish bastards in a few generations. Obviously, these will do badly since they used to be dependent on others for most of their resources. So moderate bastards might do better in the longer term since the next generation would have a better balance of selfish/altruistic individuals.