[pvaldes]

> spreading the gene that encodes this "rape others" behavior... within so many generations the gene pool would be full of rapists.

Not neccesarily. In a small society, a serial rapist would be hunted and killed quickly or forced to run away. In both cases, his children would struggle to survive without the food and protection provided by a father. Many of they would starve and not survive to reach the adulthood.

[ninkendo]

That's the point I meant by saying it's not a stable strategy to just not rape, you have to have a "punish those who do rape" trait encoded as well. Or more generally, moral standards.