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← The Descent of Edward Wilson (with Polish translation)

kriton's Avatar Jump to comment 58 by kriton

Jos, I'm not saying U is R, if by R you mean a gene for reciprocity. I'm saying U takes advantage of R already being there, it's part of the environment that can make U favorable. Leave those strawmen alone, they have a hard time as it is.

R should have been an advantage already before settling and farming, when people roamed around in small groups, so it should be widespread already.

R makes people help when they can expect something in return. But it is often difficult to know if you can expect something in return. Before settling, it would be unlikely that you got something in return from someone you were not related to, if the favour could not be returned immediately.

Because of this, people would be reluctant to help if they could not expect an immediate return. But when people settled in larger communities, the probability that someone unrelated that you helped from starvation would have an opportunity to return the favour (which he will because of R) increases, because you will probably meet again.

So at the time of settling, people would underestimate the chance of getting someting in return in the future. Now U enters the picture. U makes people help even if they don't expect something in return. But those with U will reap the benefits of their helping, the returned favour, regardless of if this is expected or not. The notU will help less than optimally, since their return-estimate is tuned to the previous situation where you are unlikely to meet again.

This will help U spread in the settled population, and situations like the famine situation will boost the ranks of U further. A part of a population has U, and those living nearby "the U starting point" will interbreed with those who have U, so to some extent it will spread by random spread. When famine strikes, those who have people with U that are not hit nearby are more likely to survive. But those who live the closest to others with U are also more likely than others to have U themselves because they have interbred. Others further away are more likely to die, and then those who are closer to the U starting point (and more likely to have U) can take over the vacant land.

By means of epigenetic regulation, U can be silenced in those who have scarce resources themselves, or experience strong stress or threat, so that way the advantages can be bigger than the disadvantages.

So under these circumstances, there would not be a pressure to reduce the U frequency.

Sat, 26 May 2012 19:19:24 UTC | #943683