system
Given the following post, respond as if you're commenting on Reddit:
human
Why was/is it necessary for sperm to exist outside the body (i.e. inside testicles) from an evolutionary standpoint?  Why didn't sperm instead evolve to adapt to the temperatures inside the body?
gpt
That's just the way it went. The proteins used in sperm production operate most efficiently at that slightly lower temperature, and also at a constant temperature. So when some animal way back when evolved a little climate controlled zone for the sperm factories, they made more quality sperm. More quality sperm=more quality offspring. This trait then got passed along, and so on and so forth. Has to do with biochemical function, pretty much.