Origin of Life: Saved by Time?
Walter Bradley
Casey Luskin
Editor’s note: We are delighted to present a series by Walter Bradley and Casey Luskin on the question, “Did Life First Arise by Purely Natural Means?” This is the fifth entry in the series, a modified excerpt from the recent book The Comprehensive Guide to Science and Faith: Exploring the Ultimate Questions About Life and the Cosmos. Find the full series so far here.
Many materialists believe that the severe unlikelihood of the series of events required for the origin of life is not a serious problem because there is essentially unlimited time for these events to occur. George Wald expressed this sentiment in 1954, writing in Scientific American, “Time is in fact the hero of the plot.” Since he believed there were billions of years available for the origin of life on Earth, Wald poetically hoped, “Given so much time, the ‘impossible’ becomes possible, the possible probable, and the probable virtually certain. One only has to wait: Time itself performs the miracles.”1 But time isn’t unlimited.
A Hostile Environment
First, the early Earth was a hostile environment for any nascent biomolecules and even early life. While the Earth formed at about 4.54 billion years ago, the crust did not begin to solidify until about 4.4 to perhaps as late as 4 billion years ago.2 Second, large bolide impact events occurred during the “heavy bombardment period” which lasted on Earth until about 3.8 billion years ago3 — impacts large enough to vaporize the oceans and sterilize Earth’s surface of any early life or prebiotic molecules.4 Third, there is now good evidence of cellular life existing as early as 3.77 billion years ago based upon the presence of microfossils in jasper cherts in the Nuvvuagittuq belt in Quebec, Canada.5
Does this evidence imply less than 30 million years from the point at which Earth became habitable to the evidence of the first life? That may seem like a long time, but on geological timescales it is considered short.
The Earliest Life
Indeed, decades after Wald, such fossil evidence of early life led theorists to say things like “we are left with very little time between the development of suitable conditions for life on the Earth’s surface and the origin of life”6 and “we are now thinking, in geochemical terms, of instant life…”7 While the precise dates of the earliest life and estimates of the onset of Earth habitability vary and these issues are debated vigorously in the literature, the point is clear: There is not unlimited time for the origin of life.
Time is not the hero of the plot; rather, it is the antagonist. The Herculean feats required by origin-of-life models are matched only by the poverty of resources available on the early Earth in terms of time and available chemical reactants. No wonder Francis Crick, the Nobel Prize-winning biochemist who co-discovered the structure of DNA, lamented, “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.”8 Based upon current knowledge, the first life could not have arisen by purely natural means.
Notes
1)George Wald, “The Origin of Life,” Scientific American (August 1954), 44-53.
2)Steering Committee on Science and Creationism, National Academy of Sciences, Science and Creationism: A View from the National Academy of Sciences (Washington, DC: National Academy Press, 1999), 5.
3)Ronny Schoenberg, Balz S. Kamber, Kenneth D. Collerson, and Stephen Moorbath, “Tungsten isotope evidence from, 3.8-Gyr metamorphosed sediments for early meteorite bombardment of the Earth,” Nature 418 (July 25, 2002), 403-405.
4)Norman H. Sleep, Kevin J. Zahnlet, James F. Kasting, and Harold J. Morowitz, “Annihilation of ecosystems by large asteroid impacts on the early Earth,” Nature 342 (November 9, 1989), 139-442; Kevin A. Maher and David J. Stevenson, “Impact frustration of the origin of life,” Nature 331 (February 18, 1988), 612-614; Norman H. Sleep and Kevin Zahnle, “Refugia from asteroid impacts on early Mars and the early Earth,” Journal of Geophysical Research 103 (November 25, 1998), 28, 529-528, 544; E.G. Nisbet and N.H. Sleep, “The habitat and nature of early life,” Nature 409 (February 22, 2001), 1083-1091.
5)Matthew S. Dodd, Dominic Papineau, Tor Grenne, John F. Slack, Martin Rittner, Franco Pirajno, Jonathan O’Neil, and Crispin T.S. Little, “Evidence for early life in Earth’s oldest hydrothermal vent precipitates,” Nature 543 (March 2, 2017), 60-64.
7)Stephen Jay Gould, “An Early Start,” Natural History 87 (February 1978), 10.
8)Cyril Ponnamperuma quoted in Fred Hoyle and Chandra Wickramasinghe, Evolution from Space (New York: Simon & Schuster, 1981), 76.
9)Francis Crick, Life Itself: Its Origin and Nature (New York: Touchstone, 1981), 88.
