[Rudder]

Thanks.

Well, at one point our ancestors were cold-blooded, some were aquatic, some had photoperiod-regulated gonads. I guess all these changes that led to a warm-blooded mammal didn't happen all at once nor by the same mechanism. Descended testicles could be just one mechanism for temperature regulation (there are other ways) of an organ, it worked and it stuck.

But when the statement says, "..for no good reason..." I take it to mean, "for no good reason."

[xmission]

But when the statement says, "..for no good reason..." I take it to mean, "for no good reason."

I'm not a scientist, and I understood the meaning.

We have to wonder why the process would continue for millions of years if it wasn't "working and sticking".