, particularly the scrotal assembly (scrotum
One of the oddest human body parts, no one knows exactly why the scrotal assembly is put together the way it is. However, many scientists now theorize that, much like the worm-lure tongue of the Alligator snapping turtle, the scrotal assembly's appearance evolved as a lure to help prehistoric man catch and kill otherwise deadly wooly mammoths.
When a mammoth was spotted, one man would climb onto a stump, rock, etc. and shout out mammoth calls while dangling his junk in full view of the animal. The mammoth, entranced by this display, would stumble drunkenly toward the man with its mouth watering and its trunk outstretched ready to pluck the sweet sweet prize from the hunter.
Then, suddenly, the rest of the hunters would spring up from behind the bushes and spear the mammoth which, even while dying, would never take its eyes off the bait. Often, the mammoth's mouth would continue to water for an hour or so after death, and while some speculate that this was merely a reflex action, others suspect that as the mammoth's brain shut down, it saw before it a brilliant tunnel of light with hundreds of juicy nutsacks at the end.
After the extinction of the wooly mammoths, the scrotal assembly has become essentially a vestigial appendage whose unique appearance no longer serves a purpose, much like the appendix.