I'm confused by your comment. Pubic lice made the jump to human ancestors after we lost body hair and then likely gained pubic hair. We had diverged from gorillas long before then.
It is very unlikely a few human types had sex with gorilla's. Modern man does, we'll call them strange, things. Most likely we picked up the lice while eating gorilla meat.
I meant that the strain of primates that developed into human beings wouldn't be a seperate stain from the primates that developed into gorrilla if the two groups didn't have sufficient time apart to speciate. It had nothing to do with the lice, I was just commenting that until there is geographic seperation, there can be no speciation.
