Shadows of Forgotten Ancestors

Once the time scale for the terrestrial drama had been extended to billions of years, much that had once seemed impossible could now be readily explained as the concatenation of apparently inconsequential events—the footfalls of mites, the settling of dust, the splatter of raindrops. If, in a year, wind and water rub a tenth of a millimeter off the top of a mountain, then the highest mountain on Earth can be flattened in ten million years. Catastrophism gave way to uniformitarianism, championed by Lyell in geology and by Darwin in biology. The accumulation of vast numbers of random mutations was now inevitable, unavoidable. Great cataclysms were discredited and special creation became, both in geology and biology, a redundant and unnecessary hypothesis.

Many advocates of uniformitarianism denied that quick and violent biological change had ever occurred. T. H. Huxley, for example, wrote, “There has been no grand catastrophe—no destroyer has swept away the forms of life of one period, and replaced them by a totally new creation: but one species has vanished and another has taken its place; creatures of one type of structure have diminished, those of another have increased, as time has passed on.”¹⁴ In the light of modern evidence, he was right in general, right for most of the history of the Earth. But he went too far; clearly it is possible to acknowledge the importance of slow, cumulative, background change without denying the possibility of occasional global cataclysms.

In recent years it has become increasingly evident that catastrophes have swept over the Earth, generating vast alterations both in land-forms and in life. Major worldwide discontinuities in the record in the rocks are readily explained by such catastrophes; and abrupt transitions in the forms of life on Earth, occurring in the same epoch, are naturally understood as mass extinctions, times of great dyings. (Of these, the late Permian is the most extreme example, and the late Cretaceous—when the dinosaurs were all snuffed out—the best-known). Previous ecologies are then supplanted wholesale by new teams of organisms. The fossil record shows that long periods of very slow evolutionary change are often interrupted by rarer, episodic intervals of quick change, the “punctuated equilibrium” of Niles Eldredge and Stephen J. Gould.¹⁵ We live on a planet in which both catastrophes and uniform change have played their roles. In the purported distinction between all-at-once and slow-and-steady, as in much else, the truth embraces seemingly antithetical extremes.

The case for special creation has not been strengthened by this new balance. Catastrophism is an awkward business for biblical literalists: It suggests imperfections in either the design or the execution of the Divine Plan. Mass extinctions permit the survivors to evolve quickly, occupying ecological niches formerly closed to them by the competition. The painstaking selection of mutations continues, catastrophes or no catastrophes. But the wiping out of whole species, genera, families and orders of life, the randomness of mutation, the infelicities in the molecular machinery of life, and the slow evolutionary fiddling displayed in the fossil record—of trilobites, say, or crocodiles—all reveal a tentativeness, a hesitancy, an indecision that hardly seems consistent with the modus operandi of an omnipotent, omniscient, “hands-on” Creator.

——

Why are many cave fish, moles, and other animals that live in perpetual darkness blind, or nearly so? At first the question seems ill-conceived, since no adaptive reward would attend the evolution of eyes in the dark. But some of these animals do have eyes, only they’re beneath the skin and don’t work. Others have no eyes at all, although anatomically it’s clear that their ancestors did. The answer seems to be that they all evolved from sighted creatures that entered a new and promising habitat—a cave, say, lacking competitors and predators. There, over many generations, no penalty is paid for the loss of eyesight. So what if you’re blind, as long as you live in pitch darkness? Mutations for blindness, which must be occurring all the time (there being many possible malfunctions in the genetic instructions for vision—in eye, retina, optic nerve, and brain), are not selected against. A one-eyed man has no advantage in the kingdom of darkness.