I Have Landed (52 page)

Originally interpreted as a feathered dinosaur
, Caudipteryx
(left) may be a secondarily flightless bird
. Oviraptor
(right) was named “egg thief” because its skeleton was found atop fossilized eggs. Later studies showed it was probably protecting its own nest
.

After considerable puzzlement, I think that I finally understand the reason for such a stark contrast between my lack of surprise and the sense of deep paradox conveyed by most press reports. As an implication of my view (expressing a professional consensus) that evolutionary novelty arises by a process of branching, the discovery of an earlier “first time” for a common and repeated event—loss of flight and secondary adaptation to effective ground running—surely attracts interest as a lovely nugget of discovery but scarcely evokes any theoretical surprise.

But in the usual public misconception of evolution as a story of wholesale transformation into something better, such an early “falling off from “the program”
seems almost perverse. After all, birds had just taken to the air a few tens of millions of years (at most) before the appearance of
Caudipteryx
. Why would a lineage fall out of step so early in the game? Once the program rolls to a full and triumphant completion, then evolution might permit an ostrich or two to slip off the main line and pursue its own bohemian path in a now strange but once ancestral land. But such events surely cannot occur in the vigorous youth of a lineage that has just snatched winged victory from the jaws of terrestrial dinosaurian death.

Perhaps I have treated a garden-variety error with unfair disdain in the sarcasm of the preceding paragraph. But the fallacy behind this common feeling of surprise, evoked by the eminently plausible hypothesis of
Caudipteryx
as a flightless bird, originates in a pervasive bias that renders much of the fascination of evolution inaccessible to millions of genuinely interested students and lovers of science.

The vigorous branching of life's tree, and not the accumulating valor of mythical marches to progress, lies behind the persistence and expansion of organic diversity in our tough and constantly stressful world. And if we do not grasp the fundamental nature of branching as the key to life's passage across the geological stage, we will never understand evolution aright. Tennyson caught the essence of life's challenge when he personified nature's unforgiving geological ways, as expressed in the fossil record of extinction:

Yes, all shall eventually go, but some shall branch, thus permitting life to persist. To cite a sardonic song of self-mockery in leftist circles: “Trotsky got the ice pick [the weapon used by his murderers]. . . and so say all of us.” And I do shudder even to contemplate the fate of the poor tailor. But the totality of life feints, dodges, and branches—and therefore, above all, hangs on in beauty and fascination. Psalm 1 invokes the right picture for a different purpose: “And he shall be like a tree planted by the rivers of water . . . his leaf also shall not wither; and whatsoever he doeth shall prosper.” And Darwin employed the same image, both as metaphor and as literal topology this time, in the final words of the focal chapter in
The Origin of Species
—chapter 4, titled “Natural Selection,” with its closing literary flourish on extinction and branching as the motors of evolution's tree and life's glory:

As buds give rise by growth to fresh buds and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications.

A
N
IMPORTANT, BUT WIDELY UNAPPRECIATED, CONCEPT
in evolutionary biology draws a clear and careful distinction between the historical origin and current utility of organic features. Feathers, for example, could not have originated for flight because five percent of a wing in an evolutionary intermediate between small running dinosaurs and birds could not have served any aerodynamic function (though feathers, derived from reptilian scales, provide important thermodynamic benefits right away). But feathers were later co-opted to keep birds aloft in a most exemplary fashion (see essay 23 for a detailed discussion of this subject). In a similar manner, our large brains could not have evolved to permit modern descendants to read and write, though these much later
functions now define an important aspect of the modern utility of consciousness.

Similarly, the later use of an argument, often in a context foreign or even opposite to the intent of originators, must be separated from the validity and purposes of initial formulations. Thus, for example, Darwin's theory of natural selection cannot be diminished, either morally or scientifically, because later racists and warmongers perverted the concept of a “struggle for existence” into a rationale for genocide. However, we must admit a crucial difference between the origin and later use of a biological feature, and the origin and later use of an idea. The first, or anatomical, case involves no conscious action and cannot be submitted to any moral judgment. But ideas originate by explicit intent for overt purposes, and we have some ethical responsibility for the consequences of our deeds. An inventor may be fully exonerated for true perversions of his purposes (Hitler's use of Darwin), but unfair extensions consistent with the logic of original motivations do entail some moral demerit (academic racists of the nineteenth century did not envision or intend the Holocaust, but some of their ideas did fuel the “final solution”).

I want to examine the concept of “native plants” within this framework—for this complex concept includes a remarkable mixture of sound biology, invalid ideas, false extensions, ethical implications, and political usages both intended and unanticipated. Clearly, Nazi ideologues provided the most chilling uses (see articles of J. Wolschke-Bulmahn and G. Groening, cited in the bibliography to this essay, for example). In advocating native plants along the
Reichsautobahnen
, Nazi architects of the Reich's motor highways explicitly compared their proposed restriction to Aryan purification of people. By this procedure, Reinhold Tiixen hoped “to cleanse the German landscape of unharmonious foreign substance.” In 1942 a team of German botanists made the analogy explicit in calling for the extirpation
Impatients parviflora
, a supposed interloper: “As with the fight against Bolshevism, our entire Occidental culture is at stake, so with the fight against this Mongolian invader, an essential element of this culture, namely the beauty of our home forest, is at stake.”

At the other extreme of kindly romanticism, gentle arguments for native plants have stressed their natural “rightness” in maximally harmonious integration of organism and environment, a modern invocation of the old doctrine of
genius loci
. Consider this statement, for example, from a 1982 book by C. A. Smyser and others, titled
Nature's Designs: A Practical Guide to Natural Landscaping:

In other words, these authors claim, evolution has produced a harmony that contrived gardens can only defy.

Or consider these words from former President Clinton (though I doubt that he wrote the text personally), in an April 26, 1994, memorandum “for the heads of executive departments and agencies” on “environmentally and economically beneficial practices on federal landscaped grounds”: “The use of native plants not only protects our natural heritage and provides wildlife habitat, but also can reduce fertilizer, pesticide, and irrigation demands and their associated costs because native plants are suited to the local environment and climate.”

This general argument boasts a long pedigree, as well illustrated in Jens Jensen's remark in
Our Native Landscape
, published in his famous 1939 book,
Siftings:

Yet the slippery slope from this benevolent version toward dangerous
Volkist
nationalism may be discerned, and quite dramatically, in another statement from the same Jens Jensen—this time published in a German magazine in 1937.

How tenuous the space between
genius loci
(and respect for all the other spirits in their proper places as well)—and “my
locus
is best, while others must be uprooted, either as threats or as unredeemable inferiors.” How easy the fallacious transition between a biological argument and a political campaign.

When biologically based claims engender such a range of political usages (however dubious, and however unfairly), we encounter a special responsibility to examine the scientific validity of the underlying arguments, if only to acquire weapons to guard against usages that properly inspire our ethical opposition. Any claim for preferring native plants must rest upon some construction of evolutionary theory—a difficult proposition to defend (as I shall argue) because evolution has been so widely misconstrued and, when properly understood, so difficult to utilize for the defense of intrinsic native superiority. This difficulty did not exist in pre-Darwinian creationist biology, because the old paradigm of “natural theology” held that God displayed both his existence and his attributes of benevolence and omniscience in the optimal design of organic form and the maximal harmony of local ecosystems. Native must therefore be right and best because God made each creature to dwell in its proper place.

But evolutionary theory fractured this equation of existence with optimality by introducing the revolutionary idea that all anatomies and interactions arise as transient products of complex history, not as created optimalities. Evolutionary defenses of native plants rest upon two quite distinct aspects of the revolutionary paradigm that Darwin introduced. (I shall argue that neither provides an unambiguous rationale, and that many defenders of native plants have mixed up these two distinct arguments, therefore rendering their defense incoherent.)

Popular impression regards Darwin's principle of natural selection as an optimizing force, leading to the same end of local perfection that God had supplied directly in older views of natural theology. If natural selection works for the best forms and most balanced interactions that could possibly exist in any one
spot, then native must be best—for native has been honed to optimality in the refiner's fire of Darwinian competition. (In critiquing horticulturists for this misuse of natural selection, I am not singling out any group for an unusual or particularly naïve misinterpretation. This misreading of natural selection has become pervasive in our culture, and also records a primary fallacy of much professional thinking as well.)

In
Siftings
, Jens Jensen expressed this common viewpoint with particular force:

But natural selection does not preferentially generate plants that humans happen to regard as attractive. Nor do natural systems always yield rich associations of numerous, well-balanced species. Plants that we label “weeds” will dominate in many circumstances, however transiently (where “transient” can mean more than a human lifetime on the natural time scales of botanical succession). Such weeds cannot be called less “native”—in the sense of evolving indigenously—than plants of much more restricted habitat and geography. Moreover, weeds often grow as virtual monocultures, choking out more-diverse assemblages that human intervention could maintain. C. A. Smyser, in his 1982 book previously cited in this article, admits the point, but does not seem to grasp the logical threat thus entailed against an equation of “natural” with “right” or “preferable.” Smyser states: