Over the weekend, my friends and I got onto the subject of vestigial body parts. My friend Simon became particularly entranced with the thought of our tailbones growing out tails again. “I think it would be pretty cool if we did have tails,” Simon said. “Then, on dates, we’d be able to hold tails.” It’s a cute idea.

Hell, try to think of an animal species without a tail. It can make a human feel quite left out to be the one of the few species without one. I wonder if we would feel more camaraderie with our animal friends if we had tails like them.

What kind of tails would we have? Long, substantial tails, like kangaroos? Or slim, sexy tails, like stingrays? Maybe guys would want to grow the former and girls the latter. Or maybe we would all get stuck with little, curly, pig-like tails. Would our tails be fleshy like the rest of our skin, or furry like Zidane, the Final Fantasy character. I personally vote that our tails look like a really big index finger.

We should think about the abilities our tails will have. Can we hang off branches or fight with our tails? Can we wrap them around ourselves? What if we want to escape from enemies — can we leave our tails behind and grow new ones, like lizards? Or will our tails be more decorative than functional?

Just imagine our current world with tails. First of all, where the hell would we put them? I’m assuming we would have “tail sleeves,” right above our asses. Or maybe our sense of propriety would be different, and we would just bare our tails along with our asses, using thongs to cover the rest of our junk. How about the general act of sitting and lying down, would we accommodate the tails with things like tail rests or just situate ourselves in tail-friendly positions?

We would probably decorate our tails with jewelry, paint or tattoos, and for sure we would use plastic surgery to enhance tail beauty. Assassinations via poison-tipped tails would be the ninja move of choice.

Tails would raise a host of new issues for males, due to tails’ similarities to the other male appendage. Would assumptions be made on the length of one’s “front tail” by the length of the back one? Lord knows that “ENLARGE YOUR TAIL” messages would fill our spam boxes. Would we get our tails circumcised? Would our tails do funny things when we became aroused? Boys would probably scope out female tails, and I bet girls would do the reverse. But the bigger question is, would you be classified as an “ass, legs and tail” man, or would tails have to compete separately against the other notable parts of the female body?

Yes, we would do a lot of things with our tails, from facilitating romance to tail-wrestling to using them as bait for fishing. Perhaps with our ever-increasing knowledge of biotechnology, one day we’ll stick it to natural selection and genetically engineer our tails back into their rightful place. But let’s all decide now what kind of tail we want before a few unfashionable biologists choose for us.

Would you be a tail man? Email zivs "at" stanford.edu.