“Obviously the law varies in its details from species to species. In ducks, the law is written for ducklings and it reads, ‘Stick to mom no matter what.’ In goats, the law is written for the mother, and it reads, ‘Suckle only your own.’”
I thought about that for a bit and asked how “Suckle only your own” fosters life for goats.
“Let’s say White Goat and Black Goat each have a suckling kid. Black Goat dies, so her kid comes over to White Goat and says, ‘Hey, I’m hungry, how about some lunch?’ The best chance White Goat’s kid has for survival is if its mother says to this stranger, ‘Get lost, kid, you’re not min
e.’ If White Goat says, ‘Okay, sure, pull up a teat,’ she’ll be diminishing her own kid’s chance for survival—which means her own genes’ chance for survival.”
“Yes, I can see that.”
“Here’s a more general statement of the law as it’s followed by goats: ‘If your resources are of doubtful sufficiency for two offspring, then you’re better off giving all to one than half to each.’”
“Not the law of kindness.”
“I would say rather, ‘Not the law of futile kindness.’ I think most mothers would rather have one live child than any number of dead ones. Nonetheless, it’s certainly true that, if the two are in conflict, the law favors life over kindness. Those who follow the contrary law—the law that favors kindness over life—will tend to lose their representation in the gene pool of their species. This is because their offspring will tend to survive and reproduce less often than the offspring of those who follow the law that favors life.”
“I understand.”
“On the subject of kindness … I don’t know if you know David Brower—one of the century’s foremost environmentalists, the founder of the John Muir Institute, Friends of the Earth, and Earth Island Institute. He tells this story of one of his earliest adventures as a naturalist. At the age of eleven he collected some eggs of the western swallowtail butterfly and kept an eye on them as they hatched into caterpillars, which later turned into chrysalides. Finally the first of the chrysalides began to crack open, and what Brower saw was this: The emerging butterfly struggled out, its abdomen distended by some sort of fluid that was pumped out over its wings as it hung upside down on a twig. Half an hour later it was ready to fly, and it took off. As the other chrysalides began to crack, however, Brower decided to make himself useful. He gently eased open the crack to facilitate the butterflies’ emergence, and they promptly slid out, walked around, and one by one dropped dead. He had failed to realize that the exertions he had spared the butterflies were essential to their survival, because they triggered the flow of fluid that had to reach their wings. This experience taught him a lesson he was still talking about seventy years later: What appears to be kind and is meant to be kind can be the reverse of kind.”
“I understand.”
“Among goats, it’s the mother that enforces this law: ‘If your resources are of doubtful sufficiency for two, then you’re better off giving all to one than half to each.’ Among eagles (and many other bird species), it’s enforced by the elder of the two offspring. The female will typically produce two eggs a few days apart, which is naturally better survival policy than producing a single egg. But if the first chick survives, it will almost invariably peck or starve the younger chick to death.”
I said, “I guess it was my impression that infanticide was explained as a reaction to overcrowding.”
“Yes, it used to be explained that way, but this argues a perception of evolution that ultimately didn’t stand up to close examination—a perception of evolution as promoting what’s ‘good for the species.’ It now seems clear that evolution promotes what’s good for the individual, in the sense of assuring the individual’s reproductive success—what I’ve been calling ‘representation in the gene pool.’”
I see.
“In lions and bears, females will often abandon a litter that has only one survivor—even if this one survivor is in perfect health. This isn’t ‘good for the species’ in any way, but it’s good for the individual’s lifetime reproductive success. Her representation in the gene pool will definitely improve if she invests exclusively in litters larger than one.”
“I have to admit that this is all news to me.”
“No one can know everything,” she said with a shrug.
“Show me where we’re going here. I’m feeling lost again.”
“I can’t teach you the whole of the Law of Life in a single night, Jared. I couldn’t teach you the whole of it if we came here every night for a decade. What I can do in a single night is present you with a few pieces of it, in the manner of a bricoleur. But let’s reach for some pieces in a new direction.”
The Law of Life: a mouse burial
She stood up, and I started to follow her example, but she told me to stay put. “Let’s see if I’m lucky tonight,” she said, and ducked into the underbrush straight ahead of us, clearly the huntress in search of a scent. I closed my eyes, grateful for the break. Returning after ten or fifteen minutes from the right, she beckoned me to follow her, which I did with some apprehension. I don’t know whether it’s a guy thing or a people thing, but I don’t like being made to feel like a greenhorn, as I suspected I was going to be. Not more than ten paces in, she stopped, crouched, and invited me to inspect a bare patch of ground the size of a checkerboard. I identified it at a glance: “Dirt.”
She shook her head impatiently and picked up a twig, which she used as a pointer, showing me something here, there, and everywhere. Looking closely, I spotted clumps of dry grass, twig parts, bits of bark, broken leaves, and more dirt.
“Don’t do this to me,” I told her. “I’m not Natty Bumppo and never will be.”
She didn’t argue. Instead, she reached her twig over to raise a branch of a low bush and invited me to have a look under it. What it looked like was a dead mouse being buried like a bather at the beach. Only its head showed, nestled in a little mound of dirt. As I watched, in the dimmest possible light, the ruffle of dirt around its neck bubbled here and there, and the mouse visibly slid back a millimeter, as if literally sinking into the earth.
“In an hour or so,” B explained, “the mouse will be completely underground and out of sight, the work of burying beetles that are digging the soil out from under it.”
She lowered the branch, and I asked what she’d been trying to show me in the dirt in front of the bush. She used her twig as a pointer as she tried to show me the signs. “The beetles—I’m pretty sure there are just two of them—found the mouse’s carcass here but evidently didn’t care for this as a burial site, so they carried it to a more sheltered site under that branch.”
“Two beetles carried the mouse?”
“What they do is burrow under the carcass then turn over onto their backs and shove it in the direction they want it to go. It’s a very laborious process. Once they have it underground, they harden the chamber around it, and while the corpse rots, the female lays her eggs nearby so the larvae will have easy access to the carrion mass once it’s opened up.”
“Yum,” I said.