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EMERGENT COMBINATIONS. "A single-celled bacterium is alive, but if you separate the macromolecules that combined to create the bacterium, these units are not alive. Based on our knowledge of macromolecules, we would not have been able to predict that they could combine to form a living organism, nor could we have predicted all of the characteristics of the resulting bacterium." https://www.nature.com/scitable/topicpage/biological-complexity-and-integrative-levels-of-organization-468 View in LinkedIn

MOLECULAR EVOLUTION. "What we have demonstrated for the first time is that even if all you have is template-assisted ligation, you can still bootstrap the system out of primordial soup," https://publishing.aip.org/publishing/journal-highlights/origins-life-new-model-may-explain-emergence-self-replication-early View in LinkedIn

UNIVERSAL STRUCTURE. “Indeed, notwithstanding multiple code variants that continue to emerge through the study of protein coding in diverse life forms, the basic structure of the code and the majority of the codon assignments are truly universal.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

DEVIATIONS. “The genetic code is nearly universal in all extant life forms although limited deviations from the standard genetic code have been detected in many groups of organisms, particularly in organelles and parasitic or endosymbiotic bacteria with highly reduced genomes.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

INFORMATIONAL INVARIANT. “The genetic code that defines the rules of translation from the 4-letter nucleic acid alphabet to the 20-letter alphabet of proteins is arguably the single central informational invariant of all life forms.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

NOT THE WHOLE STORY. “The frozen accident can be considered the default theory of code evolution because it does not imply any specific interactions between amino acids and the cognate codons or anticodons, or any particular properties of the code.” http://www.mdpi.com/2075-1729/7/2/22/htm View in LinkedIn

THE FROZEN ACCIDENT. “Nearly 50 years ago, Francis Crick propounded the frozen accident scenario for the evolution of the genetic code along with the hypothesis that the early translation system consisted primarily of RNA. Under the frozen accident perspective, the code is universal among modern life forms because any change in codon assignment would be highly deleterious.” https://lnkd.in/dKTqJpY View in LinkedIn

FRAGMENT FROM NATURE for this and next weekend focuses on the (nearly) universal genetic code, that dominates the inheritance of life on earth, and how four letters encodes twenty letters of protein with millions upon millions of functional variants based on conformation. And although widely perceived as an elegantly designed Blueprint, in fact it is a mishmash of accidents. While the dominant genetic code, Nature, as always, has variants up its sleeve. View in LinkedIn

BEYOND EXPERIMENTS. "The assembly or emergence of life, given that the right building blocks do exist, is still out of the scope of experimental chemistry." https://scholar.google.es/scholar?start=50&q=artificial+chemistry&hl=en&as_sdt=0,5&as_vis=1 View in LinkedIn

OTHER PLAYERS. “Phylogenetic analysis of translation system components, in particular aminoacyl–tRNA synthetases, shows that, at a stage of evolution when the translation system had already attained high fidelity, the correspondence between amino acids and cognate codons was determined by recognition of amino acids by RNA molecules, i.e., proto-tRNAs.” http://www.annualreviews.org/doi/abs/10.1146/annurev-genet-120116-024713 View in LinkedIn