I Have Landed (35 page)

In a wise statement that will endure beyond the fading basis of his general celebrity, Sigmund Freud argued that all great scientific revolutions feature two components: an intellectual reformulation of physical reality and a visceral demotion of
Homo sapiens
from arrogant domination atop a presumed pinnacle to a particular and contingent result, however interesting and unusual, of natural processes. Freud designated two such revolutions as paramount: the Copernican banishment of Earth from center to periphery and the Darwinian “relegation” (Freud's word) of our species from God's incarnated image to “descent from an animal world.” Western culture adjusted to the first transformation with relative grace (despite Galileo's travails), but Darwin's challenge cuts so much closer (and literally) to the bone. The geometry of an external substrate, a question of real estate after all, carries much less emotional weight than the nature of an internal essence. The biblical Psalmist evoked our deepest fear by comparing our bodily insignificance with cosmic immensity and then crying out: “What is man, that thou art mindful of him?” (Psalm 8). But he then vanquished this spatial anxiety with a constitutional balm: “Thou hast made him a little lower than the angels . . . thou madest him to have dominion . . . thou hast put all things under his feet.” Darwin removed this keystone of false comfort more than a century ago, but many people still believe that they cannot navigate our earthly vale of tears without such a crutch.

Denigration and disrespect will never win the minds (not to mention the hearts) of these people. But the right combination of education and humility might extend a hand of fellowship and eventually end the embarrassing paradox of a technological nation entering a new millennium with nearly half its people actively denying the greatest biological discovery ever made. Three principles might guide our pastoral efforts: First, evolution is true—and the truth can only make us free. Second, evolution liberates the human spirit. Factual nature cannot, in principle, answer the deep questions about ethics and meaning that all people of substance and valor must resolve for themselves. When we stop demanding more than nature can logically provide (thereby freeing ourselves for genuine dialogue with the outside world, rather than clothing nature with false projections of our needs), we liberate ourselves to
look within. Science can then forge true partnerships with philosophy, religion, and the arts and humanities, for each must supply a patch in that ultimate coat of many colors, the garment called wisdom. Third, for sheer excitement, evolution, as an empirical reality, beats any myth of human origins by light-years. A genealogical nexus stretching back nearly 4 billion years and now ranging from bacteria in rocks several miles under Earth's surface to the tip of the highest redwood tree, to human footprints on the moon. Can any tale of Zeus or Wotan top this? When truth value and visceral thrill thus combine, then indeed, as Darwin stated in closing his great book, “there is grandeur in this view of life.” Let us praise this evolutionary nexus—a far more stately mansion for the human soul than any pretty or parochial comfort ever conjured by our swollen neurology to obscure the source of our physical being, or to deny the natural substrate for our separate and complementary spiritual quest.

A
S
A
PALEONTOLOGIST
BY
TRADE
AND
(
DARE
I
SAY
IT
?)
A
card-carrying liberal in politics, I have been amused, but also a bit chagrined, by the current fad in conservative intellectual circles for invoking the primary icon of my professional world—Charles Darwin—as either a scourge or an ally in support of cherished doctrines.

Since Darwin cannot logically fulfill both roles at the same time, and since the fact of evolution in general (and the theory of natural selection in particular) cannot legitimately buttress any particular moral or social philosophy in any case, I'm confident that this greatest of all biologists will remain silent no matter how loudly conservatives may summon him.

At one extreme, the scourging of Darwin—the idea that if we drive him away, then we can awaken—has animated a religious faction that views an old-style Christian revival as central to a stable
and well-ordered polity. In
Slouching Towards Gomorrah
, for example, Robert Bork writes, “The major obstacle to a religious renewal is the intellectual classes,” who “believe that science has left atheism as the only respectable intellectual stance. Freud, Marx, and Darwin, according to the conventional account, routed the believers. Freud and Marx are no longer taken as irrefutable by intellectuals, and now it appears to be Darwin's turn to undergo a devaluation.”

Then, exhibiting as much knowledge of paleontology as I possess of constitutional law—effectively zero—Bork cites as supposed evidence for Darwin's forthcoming fall the old and absurd canard that “the fossil record is proving a major embarrassment to evolutionary theory.” If Bork will give me a glimpse of that famous pillar of salt on the outskirts of Gomorrah, I shall be happy, in return, to show him the abundant evidence we possess of intermediary fossils in major evolutionary transitions—mammals from reptiles, whales from terrestrial forebears, humans from apelike ancestors.

Meanwhile, and at an opposite extreme, the celebration of Darwin—the claim that if we embrace him, he will validate the foundations of our views—motivates the efforts of some secular believers determined to enshrine conservative political dogmas as the dictates of nature. In the
National Review
, for example, John O. McGinnis recently argued that “the new biological learning holds the potential for providing stronger support for conservatism than any other new body of knowledge has done.

“We may fairly conclude,” wrote McGinnis, “that a Darwinian politics is a largely conservative politics.” McGinnis then listed the biological bases—including self-interest, sexual differences, and “natural inequality”—as examples of right-wing ideology resting on the foundations of evolutionary theory.

Moreover, according to McGinnis, Darwinism seems tailor-made not only to support conservative politics in general, but also to validate the particular brand favored by McGinnis himself. For example, he uses specious evolutionary arguments to excoriate “pure libertarianism.” Thus he invokes Darwin to assert that the state maintains legitimate authority to compel people to save for their declining years or to rein in their sexual proclivities.

“The younger self is so weakly connected to the imagination of the older self (primarily because most individuals did not live to old age in hunter-gatherer societies) that most people cannot be expected to save sufficiently for old age,” McGinnis writes. “Therefore there may be justification for state intervention to force individuals to save for their own retirements.” In addition, “society may need to create institutions to channel and restrain sexual activity.”

Misuse of Darwin has not been confined to the political right. Liberals have also played both contradictory ends of the same game—either denying Darwin
when they found the implications of his theory displeasing, or invoking him to interpret their political principles as sanctioned by nature.

Some liberals bash Darwin because they misconceive his theory as a statement about overt battle and killing in a perpetual “struggle for existence.” In fact, Darwin explicitly identified this “struggle” for existence as metaphorical—best pursued by cooperation in some circumstances and by competition in others. Using the opposite strategy of embracing Darwin, many early-twentieth-century liberals lauded reproduction among the gifted, while discouraging procreation among the supposedly unfit.

The Darwin bashers and boosters can both be refuted with simple and venerable arguments. To the bashers, I can assert only that Darwinian evolution continues to grow in vibrancy and cogency as the centerpiece of the biological sciences—and, more generally, that no scientific truth can pose any threat to religion rightly conceived as a search for moral order and spiritual meaning.

To those who would rest their religious case on facts of nature, I suggest that they take to heart the wise words of Reverend Thomas Burnet, the seventeenth-century scientist: “ 'Tis a dangerous thing to engage the authority of Scripture in disputes about the Natural world . . . lest Time, which brings all things to light, should discover that to be evidently false which we had made scripture to assert.” So the Roman Catholic Church learned in the seventeenth century after accusing Galileo of heresy—and so should modern fundamentalists note and understand today when they deny the central conclusion of biology.

Those who recruit Darwin to support a particular moral or political line should remember that, at best, evolutionary biology may give us some insight into the anthropology of morals—why some (or most) peoples practice certain values, perhaps for their Darwinian advantage. But science can never decide the morality of morals. Suppose we discovered that aggression, xenophobia, selective infanticide, and the subjugation of women offered Darwinian advantages to our hunter-gatherer ancestors a million years ago on the African savannahs. Such a conclusion would not validate the moral worth of these or any other behaviors, either then or now.

Perhaps I should be flattered that my own field of evolutionary biology has usurped the position held by cosmology in former centuries—and by Freudianism earlier in our own times—as the science deemed most immediately relevant to deep questions about the meaning of our lives. But we must respect the limits of science if we wish to profit from its genuine insights. G. K. Chesterton's famous epigram—“art is limitation; the essence of every picture is the frame”—applies equally well to science.

Darwin himself understood this principle in suspecting that the human
brain, evolved for other reasons over so many million years, might be ill equipped for solving the deepest and most abstract questions about life's ultimate meaning. As he wrote to the American botanist Asa Gray in 1860: “I feel most deeply that the whole subject is too profound for the human intellect. A dog might as well speculate on the mind of Newton.”

Those who would misuse Darwin to advance their own agendas should remember the biblical injunction that provided the title to a great play about the attempted suppression of evolutionary theory in American classrooms: “He that seeketh mischief, it shall come unto him. . . . He that troubleth his own house shall inherit the wind.”

 

 

O
N
M
ONDAY
, F
EBRUARY
12, 2001,
TWO
GROUPS
OF
researchers released the formal report of data for the human genome. They timed their announcement well—and purposely—for February 12 is the birthday of Charles Darwin, who jump-started our biological understanding of life's nature and evolution when he published the
Origin of Species
in 1859. For only the second time in thirty-five years of teaching, I dropped my intended schedule—to discuss the importance of this work with my undergraduate course on the history of life. (The only other case, in a distant age of the late sixties, fell a half-hour after radical students had seized University Hall and physically ejected the deans; this time, at least, I told my students, the reason for the change lay squarely within the subject matter of the course.)

I am no lover, or master, of sound bites or epitomes, but I began by telling my students that we were sharing a great day in the history
of science and of human understanding in general. (My personal joy in a scientific event had only been matched once before in my lifetime—at the lunar landing in 1969.)

The fruit fly
Drosophila
, the staple of laboratory genetics, possesses between 13,000 and 14,000 genes. The roundworm
C. elegans
, the staple of laboratory studies in development, contains only 959 cells, looks like a tiny, formless squib with virtually no complex anatomy beyond its genitalia, and possesses just over 19,000 genes.

The general estimate for
Homo sapiens
—sufficiently large to account for the vastly greater complexity of humans under conventional views—had stood at well over 100,000, with a more precise figure of 142,634 widely advertised and considered well within the range of reasonable expectation. But
Homo sapiens
, we now learn, possesses between 30,000 and 40,000 genes, with the final tally probably lying nearer the lower figure. In other words, our bodies develop under the directing influence of only half again as many genes as the tiny roundworm needs to manufacture its utter, if elegant, outward simplicity.

Human complexity cannot be generated by thirty thousand genes under the old view of life embodied in what geneticists literally called (admittedly with a sense of whimsy) their “central dogma”: DNA makes RNA makes protein—in other words, one direction of causal flow from code to message to assembly of substance, with one item of code (a gene) ultimately making one item of substance (a protein), and the congeries of proteins making a body. Those 142,000 messages no doubt exist, as they must to build the complexity of our bodies. Our previous error may now be identified as the assumption that each message came from a distinct gene.

We may envision several kinds of solutions for generating many times more messages than genes, and future research will target this issue. In the most reasonable and widely discussed mechanism, a single gene can make several messages because genes of multicellular organisms are not discrete and inseparable sequences of instructions. Rather, genes are composed of coding segments (exons) separated by noncoding regions (introns). The resulting signal that eventually assembles the protein consists only of exons spliced together after elimination of introns. If some exons are omitted, or if the order of splicing changes, then several distinct messages can be generated by each gene.