body(caterpillar) snatching viruses.

On my commute to work, I heard something amazing on the radio. Scientists have discovered the gene on a virus that makes gypsy caterpillars act crazy. Gypsy caterpillars feed on leaves at night up on trees when they can't be seen by their predators, climbing down during the day. When they are infected with this virus, however, they stay up in the tree- a seemingly careless behavior- and when they die, spray the virus all over the leaves, infecting other caterpillars who feed on those leaves.

Eepito-yo.

So it seems like the virus manipulates the caterpillar to put itself in the most ideal position for the virus to propagate itself, although the behavior is dangerous to the caterpillar. Remind you of anything?

Hello, you. Picture source

It was unknown how the virus did this mechanistically until this group of researchers from Penn State University found the responsible gene egt, which keeps the caterpillar "feeling hungry" so that it stays up on the tree, until this bag of virus explodes as the exoskeleton melts away. You think I am kidding. I wish:

That is a dead gooey caterpillar. Picture source

This paper cites "The Extended Phenotype" by Richard Dawkins(!!!), as the egt gene provides further support for the presence of the (obviously eponymous) extended phenotypes. 

So this one gene changes the behavior of caterpillars leading them to become effective vehicles for their own propagation. What one gene would make us humans go crazy? I immediately thought- the inability to count- but I need something that would either 1) make us engage in reckless behavior OR 2) make us so irritated that we would engage in reckless behavior. One behavioral change. Thought for the day.