Shadows of Forgotten Ancestors

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