Tuesday, 19 March 2013

DNA repair as a cooperative venture

In 1995 Rick Michod published a popular science book called Eros and Evolution, wherein he re-interpreted DNA-repair as a form of cooperation:
"According to the gene repair mutation view, sex is a cooperative venture between mates. [...] As with all cooperative behaviors, it is possible to imagine cheaters in the gene repair sex game. [...] one kind of cheater might practice "selfish sex," in which it has sex only if it itself is damaged and never when it is healthy. Another kind of cheater might practice "parasitic sex," in which damaged cells would "prey" on healthy cooperative cells." (Michod 1995, 141f)
While this is strikingly similar to the George C. Williams's  conception of the cost of meiosis as the cost of cooperation with unrelated gametes (Williams 1988, see here),
Michod did not see it as a cost but a benefit of sex in the context of DNA repair (similar to swapping spare parts to make a working machine of broken ones). Rick Michod corroborated this in an E-mail saying he did not see the benefit in Williams's concept. This also agrees with the fact that Michod reviews all sorts of costs related to sexual reproduction (genome dilution, males, finding mates etc) in the earlier pages and writes of the cooperative venture in the later pages.
Adam and Eve in Paradise by Jan Brueghil the Elder and Peter Paul Rubens used as a Jacket design for Eros and Evolution (linked in from Wikimedia commons).
In 1998 Michod modeled the above quoted different strategies and found that selfish DNA-repair is stable against cooperative (altruistic) DNA-repair under most circumstances.

Maybe the DNA-repair hypothesis is out of fashion now, but what happened to the more general idea to approach the evolution of sexual reproduction from a sociobiological point of view?





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