I have made the point elsewhere that it is hard to see how Darwinian evolution - the 'survival of the fittest' - can produce altruistic behaviour. Darwin himself recognised this point.
For the record...
Altruism is not the only problem area. It is hard to see how evolution can explain the existence of humour, singing, painting, poetry, and most cookery, amongst other things. But we are talking here about altruism.
Of course, altruism is not the sort of thing you either have or you don't have. Almost everyone behaves in altruistic ways some of the time, towards some people, and some of this behaviour can be explained by evolutionary theory.
People have tried to provide an evolutionary explaination of altruism, using several different approaches.
The easy starting point is altruistic behaviour directed towards our own offspring or close relatives. They share many of our own genes, so to help them is also helping our own genes survive. And that is what it is all about.
This explains selfless ants, and an amount of human behaviour. But it does not explain why people give to charities to help people they will never meet, or risk their lives for the sake of strangers.
Another approach is reciprocity: I risk my life for you, in the hope that you will reciprocate and risk your life for me or my children one day.
This can explain why I might invest my time and energy to help my neighbours - those with whom I don't share any close genetic ties, but who will probably be around to help me out when I need it.
But, again, this simply doesn't provide any evolutionary reason why I should help or risk my life for a stranger.
Between-group selection had been considered and discounted by evolutionists, but is now being put forward again. It is described in an article by Wilson and Wilson in the 3 November 2007 edition of New Scientist, pages 42-46.
In abstract terms, the concept clearly works. It is the solution Darwin came up with: groups containing mainly altruists have a decisive advantage over groups containing mainly selfish individuals, even if selfish individuals have an advantage over altruists within each group.
The article correctly observes that there are circumstances in which between-group selection is important. However, "Some of the best evidence comes from microbes," which should be worrying for anyone who thinks this solves the problem.
In fact, only two examples of between-group selection are provided.
One of them concerns lions defending their territory. This would translate directly into the human habit of warfare. I can readily see that in the context of warfare, an army of altruistic people will defeat an army in which everyone is out to save their own skin. This would explain bravery and bonding in the army, but not generosity to strangers.
The other example concerns groups of bacteria and viruses maintained under "biologically plausible migration schemes". It was found that 'prudent' virus strains were able to outcompete more 'rapacious' strains, despite their selective disadvantage. For some reason, the authors fail to spot that prudence is the precise opposite of altruism, which is what they are supposed to be explaining!
Nothing in the article explains how between-group selection explains the continued presence of altruism. Yes, a group consisting of mainly altruistic people will tend to succeed more than a group of mainly selfish people. But, if altruism is an evolutionary disadvantage, within each of those groups the altruists will tend to die out and be replaced by the selfish.
It makes no difference that one of the groups will have an advantage over the other, and the occasional person migrating from one group to the other makes no difference, either. It's a disadvantage, so it will be selected against, and this will be true in every group. My genes can be passed on if I am a live member of a weak, selfish group; they cannot be passed on if I am a dead member of a strong, altruistic group.
I find it interesting that I have not yet found in all the scientific literature any suggestion of the two most likely explanations of altruistic behaviour.
One possibility is female selection. If females prefer to mate with altruistic males, this would provide an evolutionary edge that more than compenstated for the average cost of altruistic behaviour.
But a stronger possibility is that altruism is a direct result of religious faith. Religious faith provides a strong evolutionary benefit, and also provides a reason why the individual might behave in altruistic ways towards strangers.
