Right now I would doubt is encoded in a group of genes. I think there is some eveidence of some network of genes and proteins.. but it is certainly seems in the biological package pre-package. Gens and proteins only set the general structure in very lousy terms.. it just seems that the general structure is fine-tuned to get fear of snakes in a specific part of the limbic system.

Probably hormones, otehr carriers, fatty acids and other biological aspects of development play a greater role here than genes...But we will know in the future for sure. we know where it is (fear), what to analyze and what to look for. In some decades we will get an idea.

Byt he way, right now I would bet that it is more encoded in fatty acids activity due to a particular structure organized by a gradient generator (whcih is generated by a proteic network).. but it is just a bet :)

Regarding monkeys and apes and spiders. Monkeys do not fear spiders. In my town no older person fears spiders (neither do I).. adders on the other hand...

A pleasure

I therefore claim to show, not how men think in myths, but how myths operate in men's minds without their being aware of the fact. Levi-Strauss, Claude