BY the time DNA testing finally brought confirmation, or something close to it, a few months ago, most paleoanthropologists had already come around to the view that Neanderthal people, though humanoid and sentient and perhaps even sentimental, were not direct ancestors of modern human beings but instead represented a side branch and an evolutionary dead end. Still, the genetic investigation was remarkable. Scientists first extracted an uncontaminated sequence of DNA from the original Neanderthal skeleton, a fossilized specimen discovered in Germany in 1856. They then compared that sequence with corresponding sequences in Homo sapiens. Because genetic mutations build up naturally within any species over time, at a rate that can be estimated, comparing parallel DNA sequences yields a snapshot of genetic closeness or distance. The comparison also allows an estimate of the date when related species began to diverge. In the case of the Neanderthals and us, according to DNA tests the two phyla began to separate 600,000 years ago. Despite the suspicions that we all entertain, little or no interbreeding appears to have occurred.
Shortly after learning about the Neanderthals, I happened to watch an installment of the CNN public-affairs program Crossfire, and a question came idly to mind. Might there be some way, analogous to the methods used in biology, to evaluate the buildup of mutations in the cultural sphere? The distinguished hosts of the Crossfire installment were John Sununu, a former chief of staff to the President of the United States, and Geraldine Ferraro, a former Democratic nominee for the office of Vice President, and on this day Sununu and Ferraro had as a guest the model-actor-caretaker-opportunist Kato Kaelin, with whom they discussed the difficulty of finding a buyer for O. J. Simpson's house in Los Angeles. (Sununu: "Kato Kaelin, you lived in this facility. You know these are supposedly great buildings with beautiful grounds, pool and all. How come nobody bid?" Kaelin: "Well, I think it's the way they did it, John.") I would be interested in knowing what the genetic analysis of a sequence from this improbable program would reveal. Is it culturally of a piece with the larger continuum -- showing somehow an evolutionary affinity, despite some mutations, with samples extracted from Austen, Disraeli, and Kant? Or are the mutations significant enough as to indicate a parallel but distinct phylum, one that split off sometime prior to the Renaissance, say, or even prior to development of the prehensile thumb?
No doubt we'll never know -- and perhaps we should be grateful. Fascinating as genetic analysis can be, I must confess to increasingly frequent episodes of what might be called DNA fatigue -- a kind of irritable lassitude brought on by DNA's prominent involvement in almost everything. Deoxyribonucleic acid, the blueprint of life, enjoys the status of truth serum and Delphic oracle, judge and jury, architect and master builder, talisman and philosopher's stone. It brooks no argument. "Evidence from archaeology and palaeontology is seldom clear-cut," an editorial writer observed in the journal after the Neanderthal findings were published, "whereas DNA research seems to provide unequivocal answers." Medieval mystics professed an awesome wonder at seeing the hand of God apparent in all things -- in the concourse of the cosmos, a blade of grass, the evanescence of a snowflake, the breath of a gnat. The sin these mystics had to fight, commentators say, was weariness at all the reminding.
The reminders of DNA are no less constant. Jurassic Park. Dolly the sheep. Almost any publicized criminal trial. Exhumations to obtain telltale genetic fingerprints now seem to take place every other week. Jesse James has been dug up for this purpose, as has the possibly innocent convicted murderer Sam Sheppard. DNA analysis was employed to confirm that bones found in a shallow grave in Ekaterinburg, Russia, were those of Czar Nicholas II and his family, executed in 1918. Potential claimants have raised the prospect of exhuming DNA from the rock star Jimi Hendrix and from the Argentine dictator Juan Peron, in each case with a view to establishing paternity. Queen Victoria remains a target of investigators, because the genetic source of the hemophilia she passed on to her descendants has never been satisfactorily explained. (There is no record of hemophilia in her parents' families, and some speculate that her mother may have taken a lover. If Victoria was illegitimate, researchers say, the British monarch today should be Prince Ernst August of Hanover, the grandson of Kaiser Wilhelm II.)
The relevance of DNA testing is nearly boundless. It led not long ago to the realization that an expanse of mushrooms in Michigan covering some forty acres was in fact a single organism -- a fungus, mostly underground, that weighs upwards of a hundred tons. Textual archaeologists are hoping that DNA from the Dead Sea Scrolls, which were written on animal skins, can help to match up hundreds of orphaned fragments. In France and England investigators have used DNA testing of mass populations to find criminal suspects who match the evidence in hand. Genetic tests now exist to predict almost 500 medical conditions. As is well known, DNA has also been implicated in predispositions ranging from sadness and shyness to aggressiveness and novelty-seeking.