Once, modern man's early ancestors chased down sabertooth rabbits and weremammoths in nothing but a loin cloth. Most fatalities were probably due to squashed balls while running after odd, non-existent meat-creatures.
Boobs, too. You ever tried running with boobs? I haven't. Some lady-people probably have. Apparently that's an uncomfortable thing to do, too.
This is why the industrial revolution had to happen. For better textiles. Because of balls and boobs. Human society's capacity for invention, I think (today. I made all this up. Probably) was largely driven not by a desire to make steam trains and keep kids out of the way somewhere deep inside a distant coalmine, but to create more practical underwear.
Now we have wonderful underwear to keep all our gubbins safe. We can run. We don't - mostly, people sit on their arses and watch a load of crap on TV. But we could run. If we wanted.
And there you have evolution explained perfectly in a few short paragraphs and don't need to read Origin of the Species at all.
You are quite welcome.
I haven't really thought this through - but if duckbill platypi/puses can exist, then this is almost definitely true.
Love you x
Ride me like a Harley, baby. Like a Harley.