October 7, 1999

Strange but true!

By BILL SONES and RICH SONES, Ph.D.
Special to the Jounal

Q. Setting aside all the myriad ethical and aesthetic objections, could chimpanzees and humans successfully interbreed?

A. No one knows--or if they do, they're keeping it to themselves, says Ian A. York, post-doctoral research fellow at the University of Massachusetts Medical Center. Let's start with a relatively simple question: Can humans and chimps interbreed to produce fertile offspring?

The answer to this one is a pretty clear "No"; chimps and humans have different numbers of chromosomes (humans have 23 pairs, chimps 24), which almost (but not completely) means any hypothetical offspring would be sterile.

Since the most commonly used definition of "species" requires that members of the same species interbreed to produce fertile offspring, this means humans and chimps are not the same species.

But members of different species can, in fact, sometimes interbreed. The most obvious examples are horses and donkeys, which are different species, have different chromosome numbers, but can interbreed like nobody's business to produce mules or hinnies.

Beyond this, though, says Dr. York, there's no simple rule for determining which species can interbreed. Humans and chimps diverged at roughly the same time as did horses and donkeys (between 5 and 10 million years ago), and very roughly they are about as similar, genetically, as are horses and donkeys. But that doesn't guarantee anything; it's a case-by-case matter. Some species which are more similar than humans and chimps cannot interbreed.

"In principle, it's entirely possible chimps and humans can interbreed. In principle, it's entirely possible that they can't. Unless the experiment is done, we won't know."

Q. Kite-flying Ben Franklin is often depicted doing his famous "sameness of electricity and lightning" experiment during a raging thunderstorm. What's wrong with this picture?

A. Franklin was never that stupid, says Jearl Walker in "The Flying Circus of Physics." A lightning strike to the kite would have destroyed it, the twine, the trivial silk shield and possibly Franklin himself. Rather, he flew his kite before the full storm arrived.

In Europe, experimenter G. W. Richmann, in attempting to duplicate Franklin's experiment, didn't fare so well, becoming an apparent victim of a mysterious type of lightning called ball lightning: "A pale blue fireball about the size of a fist left the lightning rod in his lab, floated quietly to Richmann's face, and exploded. With a red spot on his forehead and two holes in one of his shoes, Richmann was left dead on the floor."

Q. Do hermaphrodites urinate through the sexual organ of their choice, or does it only work with one? In a nutshell, how does that plumbing operate?

A. Even when both male and female organs are present, a single urethra leads out from the bladder to a single urethral opening located usually midway between the main structures, says David A. Hatch, associate professor of urology and pediatrics at Loyola University Stritch School of Medicine. Thus hermaphrodites' potty possibilities are no greater than anyone else's.