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FIDELITY IS A BY-PRODUCT. “The structure of the standard genetic code is nonrandom and ensures high robustness of the code to mutational and translational errors. However, this error minimization is most likely a by-product of the primordial code expansion driven by the diversification of the repertoire of protein amino acids, rather than a direct result of selection.” http://www.annualreviews.org/doi/abs/10.1146/annurev-genet-120116-024713 View in LinkedIn

WHY IT IS UNIVERSAL. “The universality of the code likely results from the combination of a frozen accident, i.e., the deleterious effect of codon reassignment in the standard genetic code, and the inhibitory effect of changes in the code on horizontal gene transfer.” http://www.annualreviews.org/doi/abs/10.1146/annurev-genet-120116-024713 View in LinkedIn

SELECTIVE PRESSURES. “The genetic code is not quite universal. The rare variations that we know of reveal selective pressures on the code and on the translation machinery. New data suggest the code changes through ambiguous intermediates and that termination is context dependent.“ https://www.sciencedirect.com/science/article/pii/S0960982216309174 View in LinkedIn

SELECTIVE PRESSURES. “The genetic code is not quite universal. The rare variations that we know of reveal selective pressures on the code and on the translation machinery. New data suggest the code changes through ambiguous intermediates and that termination is context dependent.“ https://www.sciencedirect.com/science/article/pii/S0960982216309174 View in LinkedIn

SECONDARY VARIATIONS. “The standard genetic code is virtually universal among extant life forms. Although many deviations from the universal code exist, particularly in organelles and prokaryotes with small genomes, they are limited in scope and obviously secondary.” https://lnkd.in/ddaxciH View in LinkedIn

NOT OPTIMAL. “However, the standard genetic code is far from being optimal because, given the enormous overall number of possible codes (>10(84)), billions of variants are even more robust to error.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

HIGH FIDELITY. “Quantitative analyses of the code using cost functions derived from physico-chemical properties of amino acids or their evolutionary exchangeability have confirmed the exceptional robustness of the standard genetic code: the probability to reach the same level of error minimization as in the standard genetic code by random permutation of codons is below 10(-6).” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

ERROR PROTECTION. “The code is robust to error, i.e., mutational and translation errors in synonymous positions (typically, the third position in a codon) have no effect on the protein, whereas substitutions in the first position typically lead to incorporation of an amino acid similar to the correct one, thus decreasing the damage.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

AN EXTRAORDINARY INITIATIVE to re-green the world by wealthy philanthropists. https://www.thetimes.co.uk/article/meet-the-knepp-group-the-billionaires-dedicated-to-rewilding-the-environment-dgqrmxl9w View in LinkedIn

SO ENDS this first weekend contemplating the (almost) universal genetic code. While this is the configuration of inheritance on this planet, it is unlikely that it should be the same signature of life on other planets, or form a basis for the search for other life forms. On Earth, it has been a lucky accident, driven by the local physical conditions and material constraints of the planet. More than likely, there are thousands of other solutions to the same basic challenge of encoding inheritance. View in LinkedIn