Origin of Life Argument
Form
As presented by Stephen Meyer (Signature in the Cell, 2009), John Lennox, and the chemist James Tour:
- Life requires self-replicating molecules carrying coded information, and the machinery (ribosomes, enzymes, membranes) to read and maintain it.
- The spontaneous assembly of even one functional protein, let alone a cell, from prebiotic chemistry is astronomically improbable. Fred Hoyle's figure for a minimal set of enzymes was one in 10^40,000, "a tornado sweeping through a junkyard" and assembling a Boeing 747.
- After seventy years of research no naturalistic pathway from chemistry to life has been demonstrated.
- Therefore the origin of life required intelligent intervention.
My Positions
- "Not yet explained" is not "inexplicable". This is the god of the gaps in its purest surviving form (Appeal to Ignorance). The gaps have a record: the synthesis of urea in 1828 ended the doctrine that organic chemistry needed a vital force; the Miller–Urey experiment of 1953 produced amino acids from a simulated early atmosphere; ribozymes, discovered in 1982, showed that RNA can both carry information and catalyse reactions, which removed the chicken-and-egg problem the argument rests on; John Sutherland's group made activated nucleotides under plausible prebiotic conditions in 2009; lipid vesicles that grow and divide have been made in the laboratory. The pathway is not complete. The direction of travel is not in doubt.
- The probability calculation is a straw man. No one proposes that a modern protein or a cell assembled by random collision. The proposals are stepwise: simple replicators, selection acting from the first molecule that copied itself better than its neighbours, and complexity accumulated by the same ratchet that evolution uses. Hoyle's number is the probability of an event nobody claims happened, and the junkyard is the Personal Incredulity of a man who did not work in the field.
- Abiogenesis is not evolution. Even a complete blank on how life began would leave the evidence for common descent untouched, as a blank on how the first word was spoken would leave linguistics untouched. The intelligent-design movement blurs the two deliberately, because the evidence for evolution is overwhelming and the origin of life is still open (Creationism and Intelligent Design).
- "A designer did it" explains nothing. It specifies no mechanism, no time, no place, and no method; it predicts nothing; it cannot be wrong (Popper's Razor). And it needs a designer at least as complex as a cell, who presumably also needed designing (Teleological Argument - Argument from Design).
- The early Earth was a planet-sized reactor with hundreds of millions of years. Estimates of improbability made without the chemistry are numerology. Where the chemistry has been done (hydrothermal vent gradients, cyanosulfidic chemistry, mineral surfaces), the "impossible" steps keep turning out to be merely difficult.
- Even granted intervention, the intervener is unidentified. Directed panspermia, aliens, a previous universe, and deism all satisfy the argument as well as the God of any religion.
I do not know how life began. There are several live hypotheses (an RNA world, metabolism-first chemistry at alkaline vents, Sutherland's one-pot chemistry) and I expect to see the question narrowed in my lifetime. "I don't know" is not a synonym for "God".
Sources
- Meyer, S., Signature in the Cell (2009)
- Hoyle, F., The Intelligent Universe (1983), for the junkyard
- Miller, S. L., "A Production of Amino Acids Under Possible Primitive Earth Conditions", Science 117 (1953)
- Powner, M. W., Gerland, B. and Sutherland, J. D., "Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions", Nature 459 (2009)
- Szostak, J. W., Bartel, D. P. and Luisi, P. L., "Synthesizing life", Nature 409 (2001)
- Martin, W. and Russell, M. J., "On the origins of cells", Philosophical Transactions of the Royal Society B 358 (2003)
- Lane, N., The Vital Question (2015)