Natural selection theory glides over the most engaging of all biological questions, namely, the origin of life. Evolution as a force clearly exists; the evidence on this point is close to overwhelming. But what evolutionary thinking does is describe the way organisms that already exist adapt to change in habitats that already exist; the theory is silent on how the process begins. Even cellular forms of life are so fantastically complex, so different from the azoic world and so fragile compared with it, that it is difficult to imagine how an incomplete, initial organism could have functioned before its components were sufficiently established to be capable of replication and development.
As Sam Berry, a professor of genetics at University College, London, has written, "Though Darwin mused about whether a prehistoric `warm pond' of chemicals struck by lightning started the chain of biology, this was strictly a musing. Natural selection theory makes no claim to being able to explain the creation of life." Proposals have been advanced that a purely natural origin of life might have occurred through initial chance chemical assembly of RNA, which is (essentially) a simpler version of DNA; through the self-duplication effect of the matrixes in clay; via other means. At present no origin of life theory has anything close to scientific consensus backing. All proposals advanced so far are extremely speculative and open to many objections, including this one: if life was created in a purely natural way driven exclusively by chemistry, then nothing should forbid the creation of life today, either in warm ponds or anyone's test tube. Yet scientific attempts to make the inanimate live have consistently failed.
Pondering the seeming extremely low probability of biology with an origin in chance forces, many researchers have come to the conclusion that life must be a chemical fluke so wildly implausible that it represents little more than a data blip. Most influential in this regard was the powerful 1972 book Chance and Necessity by the Nobel-winning French biologist Jacques Monod. In it, Monod asserted that everything about the living world could now be explained without recourse to purpose, significance, or larger powers: "Man knows at last that he is alone in the universe's unfeeling immensity, out of which he emerged only by chance."
Patinaed with what seems like objective science, the notion of life as a vacuous accident is central to contemporary intellectual orthodoxy. But while life may well be pointless, that's an opinion, not an objective induction. And it may be an opinion on the verge of collapse. Christian de Duve, a Nobel-winning Belgian biologist, says: "Eventually we will understand that the origin of life was not a highly improbable cosmic jest but rather an almost obligatory outcome of chemical structures, given the right conditions."
A branch of research generally called "complexity" theory has made progress toward showing that elaborate living molecules such as the six-billion-point strands of human DNA are surprisingly plausible. Ian Stewart, a mathematician at the University of Warwick in the United Kingdom, has suggested that mathematical rule structures inherent in existence may eventually be shown to operate as if life were their goal, encouraging the development of animation. "DNA may be just one of the many secrets of life, secrets we are only beginning to glimpse," Stewart suggests.
Conventional views about the significance of evolution may collapse as well. Darwinian theory ranks among the foremost achievements of rationality, yet many proponents insist on presenting adaptation not as a glorious manifestation of the life force but rather as just another vacant, goin'-nowhere mechanism. In this view, there is no evolutionary arrow. The living world has not gotten better or more interesting or more diverse over time; it has merely ground out meaningless genetic responses to meaningless environmental change. Development of intellect is depicted not as nature's highest (known, at least) achievement but as a random event, signifying nothing. Yet, as de Duve notes, if you "chart out the last 500 million years, you will find that nearly every animal has steadily increased its neurological capacity, if only because brainpower is a marvelous adaptation mechanism."
It is possible that life has a wholly natural origin, within some aspect of evolutionary theory that is not yet understood. But based on what is known today, it seems equally possible that some higher force or intelligence was involved. Whether that force is the divine one depicted by traditional religions, or an aspect of the universe not now known, we can only guess. What matters most is that regardless of whether life is natural or supernatural in origin, there can be meaning and purpose in our striving to lead loving lives. De Duve adds, "Intellectuals and even many scientists mistakenly think that a chance result means the result is insignificant. Chance did play a large role in evolution, but the result is highly meaningful."