The sudden appearance of a large self-copying molecule such as RNA was exceedingly improbable. ... [The probability] is so vanishingly small that its happening even once anywhere in the visible universe would count as a piece of exceptional good luck.20 Its nice to talk about replicating DNA molecules arising in a soupy sea, but in modern cells this replication requires the presence of suitable enzymes. ... [T]he link between DNA and the enzyme is a highly complex one, involving RNA and an enzyme for its synthesis on a DNA template; ribosomes; enzymes to activate the amino acids; and transfer-RNA molecules. ... How, in the absence of the final enzyme, could selection act upon DNA and all the mechanisms for replicating it? Its as though everything must happen at once: the entire system must come into being as one unit, or it is worthless. There may well be ways out of this dilemma, but I dont see them at the moment.21 The Origin of Life. This problem is one of the big ones in science. It begins to place life, and us, in the universe. Most chemists believe, as do I, that life emerged spontaneously from mixtures of molecules in the prebiotic Earth. How? I have no idea.22 evolutionnews.org/2015/01/problem_2_ungui091111.html
Posted on: Mon, 05 Jan 2015 21:00:30 +0000
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