The problem of homochirality
(The origin of life needs either pure left- or pure right- handed molecules, not a mixture)
“Experimental observations accumulated over the years have provided evidence leading—either tightly or loosely—to the various theories of the origins of biomolecular homochirality. They form a jigsaw of which some pieces are missing—perhaps in the form of definitive evidence—but this has not prevented preliminary interpretations of this puzzle being offered. And there have been many. Investigators have proposed a variety of hypotheses, but evidence in favor of each of them is at best fragmentary. Until a deeper level of understanding of the problem is reached and one theory prevails, there is a need to classify the various theories which have been proposed, possibly using different perspectives.”
(The authors go on to classify the various hypotheses.)
Editorial comment: in other words, no one has the foggiest idea how homochirality arose as a pre-requisite for life’s naturalistic origin.
Guijarro, Albert, and Yus, Miguel, The origin of Chirality in the Molecules of Life: a Revision from Awareness to the Current Theories and Perspectives of this Unsolved Problem, Royal Society of Chemistry, www.rsc.org, 2009, p. 6.