From Ivan Alexandrov:

Re: The evolution of drug abuse (March 21): One of these “other possibilities” would be that getting pleasure eating poisonous staff in some “wayward” members of population diversifies eating habits in such a way that in times of extreme when “mainstream” diet is absent these marginal individuals would survive (or help population survive) and thus rescue the genes. In a way getting addicted to mainstream food in the times of mainstream is a danger counteracted by marginals with wayward habits. This of course has broad implications for modern civilization which could be understood as an attempt to stabilize environment to such an extent that mainstream extends perhaps a bit unnaturaly at the expense of marginals.

Ivan Alexandrov, PhD
Mental Health Research Ctr
Moscow, Russia