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I think that I\u2019ll post another set of draft notes inspired by (and, to a considerable extent, drawing upon) Michael Guillen\u2019s Believing is Seeing: A Physicist Explains How Science Shattered His Atheism and Revealed the Necessity of Faith<\/em> (Carol Stream, IL: Tyndale Refresh, 2021).<\/p>\n \u00a0<\/p>\n The question of the origin of life on Earth \u2014 the question of abiogenesis<\/em>, the emergence of life from non-life \u2014 continues to puzzle researchers.\u00a0 Michael Guillen sees two broad categories of proposed solutions to the problem.<\/p>\n Jocularly, he calls the first broad category It Came from Outer Space<\/em>:<\/p>\n In this scenario, the essential ingredients of life \u2014 water, amino acids, and nucleotides \u2014 are imagined to have rained down on Earth from some external agent \u2014 such as a meteorite, comet, or space alien.\u00a0 Richard Dawkins, evolutionary biologist emeritus at the University of Oxford, explains it this way:<\/p>\n Nobody knows how it [life on earth] got started. . . .<\/em><\/p>\n It could be that at some earlier time, somewhere in the universe, a civilization evolved by probably some kind of Darwinian means to a very, very high level of technology, and designed a form of life that they seeded onto perhaps this planet. . . .\u00a0 And that designer could well be a higher intelligence from elsewhere in the universe.<\/em><\/p>\n The It Came from Outer Space\u00a0<\/em>scenario is corroborated by our discovery that comets and meteorites contain organic molecules necessary for life \u2014 even amino acids, the building blocks of proteins.<\/p>\n For instance, Meteorite 2008 TC3, which pelted northern Sudan in 2008, contains nineteen different amino acids.\u00a0 And Comet 67P\/Churyumov-Gerasimenko contains many different organic molecules and glycine, the simplest of all amino acids used by life on Earth.<\/p><\/blockquote>\n Please note that life that had been \u201cseeded\u201d onto Earth would not, strictly speaking, represent a case of abiogenesis.\u00a0 It would actually be merely a case of pushing the question of abiogenesis back further, into a long distant time in an unknown but faraway place.\u00a0 (It might also be a process that Latter-day Saints, with our rather different conception of the divine, could entertain as an interesting hypothesis or, to use a more typically Latter-day Saint term, as an intriguing speculation.)<\/p>\n Guillen calls the second of his two broad categories It Came from the Black Lagoon<\/em>:<\/p>\n In this scenario, the essential ingredients for life are terrestrial, and the process by which life emerges from them occurs entirely on this planet.\u00a0 It was Charles Darwin\u2019s own preferred idea.<\/p>\n In 1871, Darwin speculated wistfully that Earth\u2019s very first protein macromolecules might\u2019ve been cooked up by accident \u201cin some warm little pond with all sort of ammonia & phosphoric salts \u2014 [with] light, heat, electricity, [etc.] present.\u201d<\/p>\n When I was in high school, the big deal (at least at my scientific level was still a 1953\u00a0 experiment by the American chemists Harold Urey and Stanley Miller, who sought to put Darwin\u2019s \u201cwarm little pond\u201d idea to the test.\u00a0 Zapping a mixture of methane, ammonia, and hydrogen gases with electrical sparks, they were able to produce amino acids and other organic molecules.\u00a0 It wasn\u2019t actual life<\/em> yet, but these were important precursors<\/em> to life.<\/p>\n The Miller-Urey experiment was hailed, at first, but has since been heavily questioned.<\/p>\n One objection is that Earth\u2019s primitive, prebiotic atmosphere is not now believed to have consisted mostly of methane, ammonia, and hydrogen, as Urey and Miller supposed, but, instead, is thought to have consisted primarily of carbon dioxide, ammonia, and water vapor.\u00a0 One of Miller\u2019s students later repeated the experiment using a corrected gas mixture, but it seems that the results of that revised experiment are still debated.<\/p>\n Another seeming problem is that amino acids with identical chemical sequences come in two geometrical varieties, right-handed and left-handed.\u00a0 But life on Earth uses only<\/em> left-handed amino acids, while the Miller-Urey experiment (and, I presume, its variants) produces both left-handed and right-handed amino acids in equal proportions,<\/p>\n meaning that it does not represent the extraordinary, life-generating process that selected out the left-handed molecules and then assembled them into the organisms we see today.<\/p><\/blockquote>\n Recently, Guillen writes \u2014 his book was published in 2021 \u2014 scientists at McMaster University in Ontario, Canada, have created a more advanced version of the Miller-Urey device, which they call a \u201cplanet simulator.\u201d<\/p>\n By varying the temperature, humidity, pressure, atmosphere, and radiation levels inside a microwave oven-sized terrarium, the scientists can simulate the environment of early Earth or any other planet.\u00a0 It remains to be seen whether it will produce any reliable, replicable, and relevant information concerning the Black Lagoon scenario.<\/p><\/blockquote>\n Even if the Miller-Urey experiment had been entirely valid, and even if this newer Canadian version of it succeeds, there is still quite a distance between such results and the actual creation of life.<\/p>\n Yes, amino acids are the \u201cbuilding blocks\u201d of life.\u00a0 But it takes scores of them hooking up just right.\u00a0 And they must also fold themselves into just the right shape in order to create a single, healthy protein.<\/p>\n This intricate, exquisite process is like origami.\u00a0 Just one wrong fold and the end product won\u2019t look right or function properly.<\/p>\n For example, a single hemoglobin protein is made of 574 amino acids bound together in a three-dimensional, precisely interwoven, origami-like knot.\u00a0 A single mistake in the complex creation process produces a dysfunctional protein \u2014 such as we see in people with sickle-cell anemia, some of whom don\u2019t survive childhood or even infancy.<\/p>\n A living organism relies on hundreds of such carefully constructed proteins to function properly.\u00a0 Even Mycoplasma genitalium<\/em>, a sexually transmitted pathogen with one of the tiniest, most primitive genomes on the planet, relies on upwards of six hundred different, perfectly constructed proteins.\u00a0 You and I require anywhere from ten thousand to several billion different, intricately built proteins.<\/p><\/blockquote>\n