Or maybe not. Good music, though:
To this rather breezy video—which makes abiogenesis seem so easy-peezy—I offer British chemist John Walton’s recent letter to the Times Literary Supplement:
Sir, – The resilience of the “prebiotic soup” myth, in spite of torrents of counter-evidence, is truly astonishing. Even professionals such as Stephen Fletcher (Letters, December 4), criticizing Thomas Nagel’s recommendation of Signature in the Cell by Stephen C. Meyer (Books of the Year, November 27), apparently still believe in it. Fletcher asserts that “Natural selection is in fact a chemical process as well as a biological process, and it was operating for about half a billion years before the earliest cellular life forms appear in the fossil record”.
Actually the operation of neoDarwinian natural selection depends on the prior existence of entities capable of self-replication. Variants are produced in their genetic material by mutations, the variants are copied by the organism’s biochemical machinery, and then natural selection ensures the most “fit” survive. Before the arrival of organisms capable of reproduction, this process could not operate. In the words of the renowned evolutionist Theodosius Dobzhansky: “Prebiological natural selection is a contradiction in terms”. It follows that, even in principle, some quite different explanation is required to account for the origin of life. Fletcher is pinning his hopes on a supposed RNA world. He tells us: “Indeed, before DNA there was another hereditary system at work, less biologically fit than DNA, most likely RNA (ribonucleic acid)”.
It is an amusing irony that while castigating students of religion for believing in the supernatural, he offers in its place an entirely imaginary “RNA world” the only support for which is speculation! Intense laboratory research has failed to produce even one nucleotide (RNA component) under geologically plausible conditions. As for the chains of nucleotides required for the RNA world, there are insuperable problems associated with their information content, as well as the chemical selectivity needed for their assembly. Furthermore, the earth’s oldest Precambrian rocks show very good evidence that life was present from the start, so the half-billion years Fletcher counts on were actually not available for chemical evolution.
Rather than just kowtowing to the creaky naturalist “prebiotic soup” scenario, Meyer engages with the whole range of origin of life problems. Anyone interested in discovering where the evidence leads will find this a fascinating book.
JOHN C. WALTON
School of Chemistry, University of St Andrews, North Haugh, St Andrews