Ernst Mayr, renowned biologist of the 20th century, once stated, “It can hardly be doubted that biology has helped to undermine traditional beliefs and value systems.”
Does the evolution of life by dint of natural selection pose a problem for traditional theism? Viewed historically, the answer seems practically self-evident, as resistance to the idea has been confined almost entirely to the religious community. The Church and its laity have systematically deflected the idea since it first came on the scene. Its earliest proponents, Darwin, Huxley and others, suffered a glut of death threats for their untrodden ideas, and more than a century and a half later, the spurning of evolution is intimately related to accepting a religious-based alternative. It is an entanglement with no end in sight, and the enduring polarization stands as a testament to the schismatic nature of this most foundational of scientific ideas.
Intransigence toward evolution is particularly strong within Christian fundamentalism. For biblical literalists, evolution poses the intractable task of assimilating its contra-Genesis “doctrine” with parochial theology. But apart from its mutual exclusivity with inelegant interpretations of Bronze Age texts, is a contemporary understanding of evolution fundamentally at odds with the popular conceptions of God?
Beyond the debate over ancient tomes, many feel that evolution is corrosive to religious faith because it uniformly revokes any “special” status humanity once believed it held. Any arguments contending that we are somehow privileged among the order of nature or among the cosmos are all but bankrupt. Indeed, the results are in: We are half a chromosome away from chimpanzees spinning on a garden-variety planet orbiting a relatively ordinary star tucked away in an unexceptional suburb of a lone galaxy among billions. What we once assumed strangely divine turned out to be mere mediocrity.
Moreover, owing to discoveries made in the last century, we have now established that humans are one relatively short-lived peg in an unfathomably vast chain of life extending back to precellular material and to the interstellar maelstroms from whence it was forged—an infinitesimal whimper in a 4 billion-year chain of existence that, if compressed to a single year, would see man emerging within the final fifteen minutes of the calendar. Surely, to maintain faith coordinate to that of our ancestors requires deeper reserves of theological provisions.
To further expose the problems evolution generates for theistic belief, we might turn to the late Stephen Jay Gould. A good starting point is found in his 1989 work, Wonderful Life: The Burgess Shale and the Nature of History and subsequent essays. Highly regarded as one of the most iconic passages in all of science, it encapsulates precisely the dissonance created by a 10,000 foot view of evolution.
“The human species has inhabited this planet for only 250,000 years or so-roughly .0015 percent of the history of life, the last inch of the cosmic mile. The world fared perfectly well without us for all but the last moment of earthly time–and this fact makes our appearance look more like an accidental afterthought than the culmination of a prefigured plan.
“Moreover, the pathways that have led to our evolution are quirky, improbable, unrepeatable and utterly unpredictable. Human evolution is not random; it makes sense and can be explained after the fact. But wind back life’s tape to the dawn of time and let it play again from an identical starting point – and you will never get humans a second time.
“We are here because one odd group of fishes had a peculiar fin anatomy that could transform into legs for terrestrial creatures; because the earth never froze entirely during an ice age; because a small and tenuous species, arising in Africa a quarter of a million years ago, has managed, so far, to survive by hook and by crook. We may yearn for a ‘higher’ answer — but none exists. This explanation, though superficially troubling, if not terrifying, is ultimately liberating and exhilarating. We cannot read the meaning of life passively in the facts of nature. We must construct these answers ourselves — from our own wisdom and ethical sense. There is no other way.”
– Stephen Jay Gould
Within Gould’s prism, the staging of the cosmos, particularly man’s role within it, seems far removed from the realized vision of a designer–a vision suggestive of foresight or regard for the preservation of our species. Rather, the evidence intimates that humanity does not occupy the climax of any cosmic production but an accidental scene in an otherwise haphazardly produced drama. The privileged plank on which so many religions place humanity is irreversibly deposed through the lens of evolution.
Zooming to a deeper level, the details of natural selection, the primary mechanism of evolution, serve to illuminate the dissonance more fully. To the layperson, Gould’s words may seem to stand in contradiction when he says that the pathways which led to us are “improbable, unrepeatable and utterly unpredictable” while in the next breath stating that “evolution is not random.” Let’s deconstruct this language for a fuller picture.
My personal favorite definition of evolution is the following, by Richard Dawkins:
When Gould speaks of “unpredictability”, he is referring to gene mutations, the alterations which occur in DNA code. These rewrites can arise spontaneously from natural cell processes (e.g., routine errors from DNA replication and repair) or from interaction with outside agents (e.g., direct exposure to certain chemicals and mutagens or prolonged exposure to cosmic and other radiation). Each of these modifiers rearranges the order of the nucleotides in random and unpredictable ways.
The new sequences, once dispersed within a population, then rise and fall according to their relative influence on the fitness of the organism. Natural selection is only concerned with fitness, a measure of a species’ capacity to survive and reproduce in response to pressures in its environment. Selection pressures may range from predation and swings in climate and natural habitat to viruses and other pathogens. The mutations which most increase fitness have the highest probability of being passed through the population. In a sense, the calculus of natural selection works much like winning the lottery.
For example, the architecture of the human eye, the toxic acid produced by vultures, and the camouflage physiology of the squid, octopus, cuttlefish and chameleon were the result of a stepwise sequence of random mutations which survived in response to specific evolutionary pressures. If the associated mutations hadn’t emerged, these species may have died out or been pushed down an entirely different genetic track. Hence, the appearance of mutations are spontaneous and chance-derived, but the reasons for their staying power are anything but.
When Gould goes on to say that “human evolution is not random”, he is referring to after the fact, given scientific hindsight. That is, given the set of mutations operating within a population, specie evolution can be explained quite readily. However, if you were to rewind the evolutionary tape, we would see a vastly different set of mutations, resulting in very different evolutionary outcomes, which could then also be explained according to the set of environments and pressures in play.
The reason these biological realities have deep import for the “God hypothesis” should be transparently clear. Our presence here may be more improbable than a winning Powerball ticket.
What’s more, if the evolutionary pathways we observe today were all elements of a premeditated plan, then this reflects quite disadvantageously on that Architect’s adequacy. Nature is replete with examples of maladaptiveness (e.g., the female birth canal, the bifunctional nature of the throat), traits that are useless to certain species but useful in others (e.g., vestigial features like the tonsils and appendix in humans, hip and thigh bones in snakes and whales, male nipples), useful traits found in some species yet missing from others (e.g., vitamin C gene, limb regeneration), and traits which are clearly sub-optimized but still get the job done (e.g., reduced photoreception and olfaction genes in humans, the panda’s thumb).
One token example is the evolution of the eye. Much can be said about the patent inefficiency of our inverted retina, an element of our physiology which has baffled scientists for centuries. The inverted arrangement of our retina and that of most other vertebrates, in which light has to pass through several inner layers of its neural apparatus before reaching the photoreceptors (i.e., rods and cones), seems overtly dysteleological from an optical engineering perspective, not merely for its wastefulness (it would be like packing a number of additional substrates in an LCD panel, thereby cutting light transmission unnecessarily), but because it results in a blind spot. This blind spot is not common to all organisms. The rods and cones of cephalopods and other animals are affixed to the front of the retina and the optic nerve to the rear, allowing for the unimpeded transmission of light—and no blind spot.
Of course, evolution is able to account for each of these gaffes, as such phenomena are precisely what we would expect given its rubric of randomness. Natural selection does not optimize for perfection, only to configure a species for increased chance of gene flow. It is not a top-down process indicative of an “intelligent designer” but a bottom-up process where genetic configurations can only be understood post hoc. The cephalopod’s camouflage and first-rate vision demonstrate how evolution selects those traits with adaptive edge, if you are lucky enough to mutate those traits in the first place. The more we study the physiology of other life, the more superior designs we find, each of which evolved along separate evolutionary turnpikes from our own.
If we wish to posit the presence of some superintending entity, the many examples of poor and suboptimal outcomes observed across nature suggest one of three things: an absurdly incompetent designer, a malbeneficent designer or, rather parsimoniously, no designer at all. This is not to say evolution is by itself a definitive disproof of theism, though if one wants to stake belief in “God-guided” evolution, one must come to terms with these processual aberrations, along with the shoddily crafted theatrics of the overall cosmic story.