Month: September 2022

FRAGMENT FROM NATURE continues from last weekend on the theme of biological information. Most scientists today see this information as key to all life processes. How did biological information evolve? Did the transition from non-life to life come first? These are some of the interesting problems to figure out. View in LinkedIn

TRANSITION OF STATES. “We therefore identify the transition from non-life to life with a fundamental shift in the causal structure of the system, specifically a transition to a state in which algorithmic information gains direct, context-dependent, causal efficacy over matter.” http://rsif.royalsocietypublishing.org/content/10/79/20120869 View in LinkedIn

EVOLUTION OF INFORMATION. “How did information first gain causal purchase over certain complex systems that we now call living organisms?” http://rsif.royalsocietypublishing.org/content/10/79/20120869 View in LinkedIn

GENETICS OR DIGITAL FIRST? “A longstanding debate—often dubbed the chicken or the egg problem—is which came first, genetic heredity or metabolism? A conundrum arises because neither can operate without the other in contemporary life, where the duality is manifested via the genome–proteome systems.” https://lnkd.in/ewsT9EQ View in LinkedIn

RNA WORLD. “A widely accepted resolution to the seemingly inextricable duality of genotype–phenotype is that the modern ‘DNA–protein’ world evolved from simpler precursor system involving only one major molecular species that played both the role of information carrier and of enzymatic catalyst.” https://lnkd.in/ewsT9EQ View in LinkedIn

RNA TO DNA. “In modern organisms, RNA is a biochemical mediator, enabling the translation of DNA to protein. RNA is unique in that it can fill both roles, acting as both a genetic polymer and a biochemical catalyst, with novel expanded roles for functional RNAs continually being discovered. This has led to the popular ‘RNA world’ hypothesis, where all known life is posited to have descended from an ancestral population of organisms that utilized RNA as their sole major biopolymer prior to the advent of DNA and protein.” http://rsif.royalsocietypublishing.org/content/10/79/20120869 View in LinkedIn

“IN GENETICS-FIRST origin of life scenarios, it has therefore been suggested that early life may have undergone a ‘hardware upgrade’ (or a succession of upgrades), eventually transitioning from a proto-RNA genetic polymer (or even an inorganic substrate) into RNA-based biochemistry at a later stage in its evolutionary history. This system would then have undergone further hardware upgrades or ‘genetic-takeovers’ to arrive at the DNA–protein world we observe today.” https://lnkd.in/ewsT9EQ View in LinkedIn

“DIGITAL-FIRST systems (as currently posed) represent a rather trivial form of information processing that fails to capture the logical structure of life as we know it.” http://rsif.royalsocietypublishing.org/content/10/79/20120869 View in LinkedIn

“METABOLISM-FIRST’ scenarios for the origin of life fall within this analogue framework, positing that early life was based on autocatalytic metabolic cycles that would have been constructed in a manner akin to how analogue computer systems are cabled together to execute a specific problem-solving task.” https://lnkd.in/ewsT9EQ View in LinkedIn

COMPOSOMES. “The heritable information in this case typically consists of the compositional ratios of the molecules in the organized assemblies. Although it has been suggested that such ‘composomes’ might provide a primitive inheritance mechanism, it is not clear that they are evolvable, since compositional information tends to degrade over successive generations inhibiting the capacity for open-ended evolution.” https://lnkd.in/ewsT9EQ View in LinkedIn