Like the classic optical illusions—is it a candelabra, or two faces in profile?—the same data can be understood from two quite different perspectives (although neither may be fully satisfying). Each may have its own validity and utility.18 Individual selection and group selection must ordinarily go together (or, in scientific speech, be highly correlated); otherwise evolution would never occur. We might argue that individual selection must have some primacy, because you can have individuals without a group, but not vice versa. However there are many animals, primates among them, where the individual cannot survive without the group.
Strict selfishness and strict altruism are, it seems to us, the maladaptive ends of a continuum; the optimum intermediate position varies with circumstance, and selection inhibits the extremes. And if it’s too difficult for the genes to figure out on their own what the optimum mix is for each novel circumstance, might it not be advantageous for them to delegate authority? For this again, brains are needed.
Consider kin selection once more. Never mind the nagging question about how well birds, say, can distinguish uncles from cousins; especially in small groups, it doesn’t much matter—everyone’s a pretty close relative, and kin selection works in a statistical sense, even if you occasionally put yourself on the line for some unrelated neighbor. It makes sense, in terms of the preservation of multiple copies of closely related genetic instructions, to accept a 40% chance of dying to save the life of a sibling (who has 50% of the same genes you have); or a 20% chance to save an uncle or a niece or a grandchild (who share 25% of your genes); or a 10% chance of dying to save the life of a first cousin (who has 12.5% of exactly the same genes that you do). Well, then, what about giving up the means of affording another child in order to preserve the families of many second cousins? What about donating ten percent of your income so a gaggle of third cousins have enough to eat? Might it pay to abstain from a few luxuries so fourth cousins can be educated? What about writing a letter of recommendation for an undistinguished fifth cousin?
Kin selection is also a continuum, and in its arcane calculus some sacrifice must be worthwhile to aid the most far-flung and distant members of your family. But since we are all related, some sacrifice must be justified to save anyone on Earth—and not only those of our own species. Even on its own terms, kin selection extends far beyond close relatives.
Typically, any two members of a small community of primates in the wild have 10 to 15% of their genes in common19 (and about 99.9% of their ACGT sequences in common, it requiring only a single nucleotide difference to make one gene, composed of thousands of nucleotides, different from another). So any random member of the group is pretty likely to be your parent or child or sibling, uncle, aunt, nephew, niece, or first or second cousin. Even if you can’t distinguish one from the other, it makes good evolutionary sense to make real sacrifices for them—and to accept something like a 10% chance of dying in order to save the life of any one of them.
In the annals of primate ethics, there are some accounts that have the ring of parable. Consider, for example, the macaques. Also known as rhesus monkeys, they live in tightly knit cousins’ clubs.20 Since the macaque you save is statistically likely to share many of your genes (assuming you’re another macaque), you’re justified in taking risks to save it, and a fine discrimination of shades of consanguinity is unnecessary. In a laboratory setting,21 macaques were fed if they were willing to pull a chain and electrically shock an unrelated macaque whose agony was in plain view through a one-way mirror. Otherwise, they starved. After learning the ropes, the monkeys frequently refused to pull the chain; in one experiment only 13% would do so—87% preferred to go hungry. One macaque went without food for nearly two weeks rather than hurt its fellow. Macaques who had themselves been shocked in previous experiments were even less willing to pull the chain. The relative social status or gender of the macaques had little bearing on their reluctance to hurt others.
If asked to choose between the human experimenters offering the macaques this Faustian bargain and the macaques themselves—suffering from real hunger rather than causing pain to others—our own moral sympathies do not lie with the scientists. But their experiments permit us to glimpse in non-humans a saintly willingness to make sacrifices in order to save others—even those who are not close kin. By conventional human standards, these macaques—who have never gone to Sunday school, never heard of the Ten Commandments, never squirmed through a single junior high school civics lesson—seem exemplary in their moral grounding and their courageous resistance to evil. Among the macaques, at least in this case, heroism is the norm. If the circumstances were reversed, and captive humans were offered the same deal by macaque scientists, would we do as well?22 In human history there are a precious few whose memory we revere because they knowingly sacrificed themselves for others. For each of them, there are multitudes who did nothing.
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T. H. Huxley remarked that the most important conclusion he had gleaned from his anatomical studies was the interrelatedness of all life on Earth. The discoveries made since his time—that all life on Earth uses nucleic acids and proteins, that the DNA messages are all written in the same language and all transcribed into the same language, that so many genetic sequences in very different beings are held in common—deepen and broaden the power of this insight. No matter where we think we are on that continuum between altruism and selfishness, with every layer of the mystery we strip away, our circle of kinship widens.
Not from some uncritical sentimentalism, but out of tough-minded scientific scrutiny, we find the deepest affinities between ourselves and the other forms of life on Earth. But compared to the differences between any of us and any other animal, all humans, no matter how ethnically diverse, are essentially identical. Kin selection is a fact of life, and is very strong in animals that live in small groups. Altruism is very close to love. Somewhere in these realities, an ethic may be lurking.
ON IMPERMANENCE
Insignificant
mortals, who are as leaves are, and now flourish and grow warm with life, and feed on what the ground gives, but then fade away and are dead.
HOMER, The Iliad23
* Humans are newly evolved. Our availability on a global scale as hosts for parasites is very recent. In the absence of medical countermeasures, we might expect, sometime in the future, the evolution of new kinds of microorganisms that pull our strings more artfully than any rabies virus could ever do.* It’s not hard to see how the components of this “fight-or-flight” response are all adaptive—evolved to get you through the crisis. That feeling of cold and emptiness at the pit of your stomach, for example, results from a reallocation of blood from digestion to the muscles.* True, of course, only for sexual organisms. Asexual beings, reproducing by splitting in two, cannot enhance the fitness of their descendants through a spirit of self-sacrifice.* Humans do this routinely. Large multi-ethnic states are revealingly called “fatherland” or “motherland.” Leaders encourage patriotic fervor—the word “patriotic” comes from the Greek for father. Especially in monarchies, it was easy to pretend that the nation was a family. The distant and powerful king was like many fathers. Everyone understood the metaphor.