The Darwin Awards Countdown to Extinction (13 page)

1960S | My father, also a doctor, treated a man who rode his bicycle six miles one rainy evening to seek advice at the local English hospital. He wore a large, dark raincoat which he refused to remove for the nursing staff. In privacy, he did so for my father, who was most surprised. This surprise did not emanate from the fact that the man had got himself stuck in an old-fashioned clay urinal, but that he had cycled six miles with it hanging from the end of his penis! Needless to say Dad didn’t buy the story of being caught while having a wee. This ended rather badly, I am afraid. Dad claims there was no other way but to break it out with a hammer.

Could this man thus be a historic Darwin Awardee?

 

Reference: Dr. Davida Kiernan

Not the complaint of a tired housewife or the sour grapes of a frustrated “playah,” but rather a real dilemma for evolutionary biologists. If an organism’s purpose is to propagate its own DNA, why waste time and energy searching for a mate? If its unique genetic code lets it survive and flourish, why dilute that code with another creature’s genes?

Sure,
we
do. But step outside our species to recognize the big difference between sex (exchanging genes) and reproduction (making offspring). The entire kingdom Prokaryota would consider us perverts if we could explain to them how sex and reproduction coincide within our multicellular selves. Any proper prokaryote would tell you that sex—sharing genes—is something one does with multiple partners, trading bits of DNA via cell-connecting tubes or viral vectors. Reproduction, OTOH, means privately splitting your single-celled self into two identical organisms.

Asexual reproduction is actually so common that we barely think about it. Every time you pull a strawberry sucker from your garden or trim a spider plant’s spiders, you’re dealing with asexual reproduction. Bananas, the notoriously phallic fruit, are seedless and propagate by rooting cuttings. And even garlic, that spicy aphrodisiac, reproduces without sex via bulbs.

And it’s not just plants. Many worms and insects, a boatload of coelenterates (pronounced
see LEN’ ter ates’
—sea anemones and jellyfish), and even some fish and lizards reproduce asexually. Female sharks raised in captivity have given birth to all-female young whose DNA comes only from their virgin mothers. Ditto for Komodo dragons, except that through a genetic twist, their offspring are all male. Parthenogenesis has been reported as far up the evolutionary ladder as the domestic turkey.

 

Sex always costs—not necessarily in money, but in the more primal currencies of energy, time, and exposure to danger. Exhausting fights over mates raise the cost of business in the sexual world—ask any stag during rutting season. And consider over-the-top mating displays like the nine-foot blossom of the carrion flower, the peacock’s tail feathers, or the human’s silly, showy “peacock” brain. (See “Sex on the Brain,” p. 109 for a treatise on human brains and runaway sexual selection.)

Elaborate mating structures take time and energy to make and increase exposure to predators
as well as potential mates.
A peacock’s huge tail feathers slow him down; the leopard who pounces on a poky peacock is reaping a cheap lunch subsidized by the cost of sex—fancy plumage—to her prey. Time spent attracting a mate could be spent feeding, gathering energy, and growing clones. Nonsexual creatures avoid all that mating hassle by just doing it solo.

The most fascinating sex-free creatures are the ones who have given up sex after enjoying it for millions of years. There are all-female species of whiptail lizard, blue-spotted salamander, and topminnow. Tellingly, all of these species have mating behaviors that show their recent evolution from sexual ancestors. All-female blue-spotted salamanders mate with males of related species; the sperm triggers development of their eggs, but contributes no genes. The live-bearing desert topminnow,
Poeciliopsis lucidus,
does the same.

Whiptail lizards of the desert Southwest go one step further: Members of the all-female species
Cnemidophorus uniparens
take on male-like behavior and mate with other females in a process called pseudocopulation. Their female-on-female behavior stimulates egg production and the birth of clones.

If so many organisms get along fine without sex, why are the rest of us still doing it? Especially, note evolutionists dryly, when mathematical models show that asexual females should take over any population within fifty generations, due to the time and energy they save.

But—that’s fifty generations without
natural selection—
with no new trends in weather, no new diseases, no new tricks by your predators. Do you see the problem?

Nature is
never
free of natural selection. Even when the physical environment is stable, the ecosystem of predators and pathogens is not. You are food for them, and if there is one thing stronger than the sex drive, it is the need to feed. Even Darwin would agree:
You must survive until you can pass on your genes.
Food comes before sex, and organisms will do anything to get it—or avoid becoming it—even swap genes. If everyone else is swapping genes in an arms race to eat you, and you’re standing there having sex with yourself, you’re falling behind.

In a nutshell, sex is an engine of diversity: More varieties of organisms are birthed when they are conceived with a partner. A family of clones is obviously less diverse than a family with mixed genes. And when your genotype is the delicious flavor of the day, you’ll want to make sure your offspring are something your predators have never tasted before. Whether you need faster legs, a longer tongue, or slimier skin—sex is the way to go.

Now that the case has been made in favor of sex, how do creatures get by without it? If a hungry world is chasing them, why do lesbian lizards have any place in nature?

Studies show that asexual plants and animals thrive in marginal environments with little competition, but cannot compete with sexual relatives in mainstream habitats. Asexual butterflies flutter on alpine mountaintops, asexual plants pop up in plowed fields and after volcanic eruptions, and asexual vertebrates make their homes where it’s hot, icy, or dry. Note that the all-female species mentioned above are the
desert
topminnow and lizards of the
desert
Southwest. These asexual desert creatures have close relatives living in more appealing climates—lounging on beaches, soaking in tropical pools—who reproduce using sex.