>>12769689Law of large numbers, it all comes down to expected outcome of populations. What's the expected reproduction rate of 1000 chimps that have testicles inside their bodies vs 1000 chimps with testicles outside.
The heat from inside the body reduces sperm count, over the population that leads to lower reproduction rates. Getting testicles mauled is not a regular occurrence, chimps don't go around mauling each other. They contest for alpha of the pack and that can get violent but they're not trying to kill just dominate.
