Undeniable by Bill Nye

soccer matches, we play two teams at a time. Any athletic or bridge tournament involves groups of two teams. It’s hard to imagine a system that works any other way. If you have three teams on a field, it might work for a while. But pretty soon, somebody teams up with someone else and the competition becomes one-on-one, or two total at any time.
    I’ll grant you that we can have more than one individual or more than one team in a horse race or a poker game. But if this whole sex business started with microbes exchanging genes one-to-one, it’s a hard system to undo. In other words, once molecules started reproducing by dividing, it would be difficult indeed for a third team or molecule to develop and compete with a binary system. Perhaps there is an ecosystem on a planet orbiting another star—heck, perhaps there’s one on Jupiter’s moon Europa—with a tripartite sexual system. It’s a concept that Isaac Asimov explored elegantly in his novel The Gods Themselves . But a binary setup seems to be what happens when we let nature sort it (or her) self out.
    Speaking of two teams, books have been written, operas composed, game shows created, and countless news stories produced that deal with the battle of the sexes. That men and women have such difficulty getting along sometimes, or perhaps most of the time, would be a mystery, if it weren’t for evolution.
    We are all driven to select a mate. Those of us who don’t do not pass our genes on to the future. A human female is apparently driven to select a mate that will provide for her and her offspring. If nothing else, such behavior or motivation would be consistent with the tenets of sexual selection. A human male selects a mate that is, by his reckoning, well suited to carrying his genes forward. The female has to make her genes appear valuable by “playing hard to get,” as the old saying was and is so often said. But really … all things in moderation.
    Look around. So much of what goes on in our society is motivated by the process of sexual selection, and there are many subtle and not-so-subtle things that affect that process: There’s mascara. Expensive watches. Amazing shoes. Sports cars, perfume, skirts, ties, jeans, boots, and on and on. Now, compare us to everybody else. By everybody else I mean dogs and cats and lions and tigers and bears … and squids and whales. All the other animals around, and all the plants, have seasons to their mating. We humans don’t seem to. When it comes to our babies, birthdays are pretty well distributed around the calendar. Why is this? Why our species-wide sexual overdrive?
    One of the leading theories is that it’s an artifact. It’s a result of being good enough in the process of evolution. The battle of the sexes is so strong perhaps because all of us ended up with big brains (compared to other animals—and my old boss). These brains make us aware of our place in the scheme of things and that somehow leads to doubt and altruism and loyalty and the ability to so easily do the wrong thing. To keep us from not getting around to mating, our sexual selective processes are turned on 24-7. Wherever it comes from, it works. This is to say, although we are continually stymied by broken hearts, loyalty, disloyalty, professional concerns, familial criticism, and other distractions, the human species reproduces at a prodigious rate. In ten thousand years the number of people on Earth has exploded, from a few million to more than seven billion. Apparently, sexual selection left us with our need to engage turned up to eleven.
    And so I, a victim of evolution, did manage to go to the prom. It was opportunistic; I admit it. My date spent a lot of time with the older guys, guys from a class or two ahead of ours. When it was prom time, they were all in college and not available. I asked her out, and she agreed to come with. Apparently, neither one of us could help