• 01 NOV 19
    • 0

    PhD Defence – A. Blokhuis

    Monday, November 18th 2019 – PhD defence
    2PM, IPGG amphitheater
    Alex Blokhuis, ESPCI
    A. blokhuis, Physical Aspects Of Origins Of Life

    Physical Aspects of Origins of Life Scenarios
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    One of science’s grandest challenges is to explain abiogenesis, namely how abiotic matter transformed itself into life. Although many clues have been lost over the last billions of years, scenarios for abiogenesis are nevertheless strongly constrained: they must obey the laws of physics and chemistry. In this thesis, we examine how these constraints  shape prebiotic scenarios.

    Autocatalysis is common to all prebiotic scenarios. We have developed a theoretical framework for characterizing and studying autocatalysis using Stochiometric Network Analysis. This framework unifies existing approaches and unveils new forms of autocatalysis, which emerge due to coupling between multiple compartments. This work opens new routes for chemical evolution completely free of genes.

    A large family of prebiotic scenarios involves copolymers that become functional structures through the exploration of sequences. We have developed thermodynamically consistent models for key aspects of these scenarios, such as nonequilibrium polymerization (through activation, recombination or mineral adsorption), and dissipative sequence search. This highlights new pathways to long polymers.

    Finally, we have explored a general mechanism in chemical evolution, namely, transient compartmentalization. We have found that this mechanism is able to maintain functional molecules despite noise present in the composition
    and in the compartmentalization dynamics. It can also stabilize cooperation. Owing to its generality, we surmise that transient compartmentalization could be an essential element in many prebiotic scenarios.

    We are still far removed from a complete theory for chemical evolution, and possibly even further from fully understanding abiogenesis. We hope, however, to have provided new ideas and generalizations to bring these
    goals one step closer.

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