Evolution's Biggest Problem!
by Richard Peachey
[Featured as an advertorial in Cascade News, University of the Fraser Valley student newspaper, Nov. 13, 2009]
Earlier this year, a British science journal "asked some of the world's most eminent evolutionary biologists to identify the biggest gaps remaining in evolutionary theory" (New Scientist 201:41-43, 2009). Of the 16 scientists polled, two of them pointed to the same issue: life's origin. Kenneth Miller (Brown University) called this "the most profound unsolved problem in biology," and Chris Wills (University of California, San Diego) declared, "The biggest gap in evolutionary theory remains the origin of life itself."
John Horgan, the former senior science writer for Scientific American, once suggested: "If I were a creationist, I would cease attacking the theory of evolution — which is [in his view] so well supported by the fossil record — and focus instead on the origin of life. This is by far the weakest strut of the chassis of modern biology. The origin of life is a science writer's dream. It abounds with exotic scientists and exotic theories, which are never entirely abandoned or accepted, but merely go in and out of fashion" (The End of Science. New York: Broadway Books, 1995, p. 138).
Now, evolutionists may attempt to fend off this discussion by arguing, "The origin of life is not part of evolution. Evolution begins only after the rise of living cells." I do agree that biological evolution, strictly speaking, would involve the diversification of already-existing cells. But the origin of those cells is nonetheless a major concern for anyone holding to an evolutionary worldview — after all, life must originate before it can diversify. Everyone (not just creationists) refers to the startup of life through random collisions of particles as "chemical evolution." As far as I am aware, every university textbook on evolution devotes a chapter to the origin of life, and every high school biology text has a section on life's beginnings within its evolution unit. [See also: Keaton Halley's article, "Evolution: not just about biology."]
In 1953, Stanley Miller performed what is often considered to be a classic origin-of-life chemistry experiment, and is recounted in every modern biology textbook. Miller took gases theorized to have been present in the early Earth's atmosphere (methane, ammonia, water vapour, and hydrogen) and circulated them past a spark discharge representing the energy of lightning. His experiment produced several amino acids, which are the monomers ("building blocks") of the polymers we call proteins. Since proteins are key biomolecules, performing a variety of functions in our cells, the results of Miller's experiment generated great excitement. As evolutionary biologist Massimo Pigliucci has written, Miller's discovery "gave a huge boost to the scientific investigation of the origin of life. Indeed, for some time it seemed like creation of life in a test tube was within reach of experimental science."
But in his very next sentence, Pigliucci's tone changes: "Unfortunately, such experiments have not progressed much further than their original prototype, leaving us with a sour aftertaste from the primordial soup" ("Where Do We Come From? A Humbling Look at the Biology of Life's Origin." Skeptical Inquirer 23:24, 1999).
Miller himself acknowledged: "The problem of the origin of life has turned out to be much more difficult than I, and most other people, envisioned" (John Horgan, "In the Beginning . . ." Scientific American 264:117, 1991).
One serious difficulty is that the hydrogen-rich ("reducing") atmosphere required by origin-of-life enthusiasts seems unlikely to have ever existed! Atmospheric chemists now hypothesize that the early air was largely carbon dioxide (CO2) and nitrogen (N2), a mixture highly unfavourable to abiogenesis through unguided chemical reactions. As Miller himself stated in a technical article co-authored with a leading Mexican evolutionist: "There have been so many unsuccessful attempts to produce prebiotic organic compounds with CO2 + N2 + H2O mixtures (in the absence of hydrogen) that one wonders whether successful prebiotic syntheses are possible under such conditions" (Antonio Lazcano and Stanley Miller, “The Origin and Early Evolution of Life: Prebiotic Chemistry, the Pre-RNA World, and Time.” Cell 85:793f., 1996).
Francis Crick, who with James Watson elucidated the structure of DNA, once wrote: "An honest man, armed with all the knowledge available to us now, could only state that in some sense, the origin of life appears at the moment to be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going" (Life Itself. New York: Simon & Schuster, 1981, p. 88).
Noted origin-of-life researcher Gerald Joyce stated: "Modern organisms are so sophisticated that they furnish little information about what life was like before there was a genetic code and a translation apparatus. Extraterrestrial studies have yet to provide us with an alternative life form for comparison. We are left with only a partial understanding of the origins of life that is based largely on inference and conjecture" ("RNA evolution and the origins of life." Nature 338:217, 1989).
In our cells, DNA replication depends on proteins (enzymes), but proteins are coded for by the DNA. So which came first? "RNA world" proponents try to dodge this chicken-and-egg problem by suggesting that RNA formerly accomplished the functions of both DNA and proteins. But how realistic is that?
"Now that the 'RNA world' hypothesis has been canonized within most current biology textbooks, its status as a hypothesis is easily forgotten. Problems remain, particularly the implausibility of prebiotic RNA synthesis and stability. Indeed, most professional advocates of an RNA world are doubtful that life began with RNA per se. Instead, they propose that life began with an RNA-like polymer, yet to be identified, that possessed the catalytic and templating features but miraculously lacked RNA's undesirable traits, most notably, its intractable prebiotic synthesis" (David Bartel and Peter Unrau, "Constructing an RNA world." Trends in Cell Biology 9:9-13, 1999).
Some of the foregoing quotations are several years old, but they remain relevant. This year, Chris Wills (referenced above) noted that in the laboratory, chemists have produced "amino acids, primitive membrane-like structures and some of the building blocks of DNA and RNA. More recently, it has been found that, along with protein enzymes, RNA can catalyse chemical reactions, and it has even been possible to construct RNA molecules that can copy parts of themselves. But the gap between such a collection of molecules and even the most primitive cell remains enormous."
Richard Peachey is UFV's first science graduate (BSc, Biology and Chemistry, 1995); he serves as vice-president of the Creation Science Association of British Columbia