Scientists at Oregon State University have proposed that supposedly-stable DNA bases can be pushed into a "dark state" where they are highly vulnerable to damage from ultraviolet radiation. The idea challenges some of the most basic concepts of modern biochemistry.

Only tangentially-related, but I've wondered about this conceptually: when playing chess, part of a winning strategy is to play conservatively when you're ahead, and make wild, risk-taking moves when you're behind. The same strategy applies in other aspects of life, for instance, a large corporation will plod slowly but surely, while a startup must be nimble and take creative risks. I've wondered if a similar strategy wouldn't be valuable in biology: when things are going good, take steps to prevent random genetic change, and when things are not going good, encourage it.

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