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In the Girona Museum of Art is this extraordinary painting, serving to admonish Gothic laity that things do not end well for sinners. Having seen this image, it is impossible to ever forget it. View in LinkedIn

SO ENDS this first of two weekends featuring an article exploring the evolution of metabolism without available phosphate by surveying all extant metabolic pathways and modeling their non phosphate components from simple building blocks. It is an impressive tour de force of theoretical biochemistry and essentially one of the only way to probe such an evolutionary question where biochemical fossils do not exist, except as vestigial relics. View in LinkedIn

HUGE STUDY. “Here we address these questions using computational systems biology approaches originally developed for performing large-scale analyses of complex metabolic networks.” https://lnkd.in/dcwZe7b View in LinkedIn

PRECEDENT. “The thioester world hypothesis, and other phosphate-independent protometabolism models, are typically invoked to explain the prebiotic plausibility of general biochemical mechanisms, and are illustrated through specific reactions or pathways.” https://lnkd.in/dcwZe7b View in LinkedIn

SURROGATE MOLECULES. “Most notably, in the thioester world scenario, thioesters are hypothesized to have played a role similar to the one played today by ATP. Thioesters are widespread in modern metabolism, primarily as Coenzyme A (CoA) derivatives (e.g., Acetyl-CoA), and are used as condensing agents, enabling the synthesis of heterogeneous biopolymers.” https://lnkd.in/dcwZe7b View in LinkedIn

PHOSPHATE SURROGATES. “In many of these scenarios, sulfur and iron are conjectured to have fulfilled major catalytic and energetic functions prior to the appearance of phosphate.” https://lnkd.in/dcwZe7b View in LinkedIn

PROPOSED HYPOTHESIS. “The alternative solution to this dilemma is that primitive forms of life could have initially emerged and endured without a major dependence on phosphate. Multiple scenarios for early metabolic pathways that do not rely on phosphate have been proposed.” https://lnkd.in/dcwZe7b View in LinkedIn

MECHANISM. “Even provided a phosphate source, the mechanisms of phosphate utilization and polymerization in early life remain debated.” https://lnkd.in/dcwZe7b View in LinkedIn

First swallowtail of the year, a week after the first swallows arrived. View in LinkedIn

HYPOTHESES. “Currently, there is no consensus for a phosphate source in early life, with theories ranging from acid-mediated ion solubilization, high concentrations of reduced phosphorus species in early oceans, or accumulation during late heavy bombardment.” https://lnkd.in/dcwZe7b View in LinkedIn