Regensburg 2016 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 44: Biotechnology & Bioengineering

BP 44.1: Hauptvortrag

Mittwoch, 9. März 2016, 15:00–15:30, H45

Physics for the Origins of Life — •Dieter Braun — Systems Biophysics and Center for NanoScience, LMU Muenchen, Amalienstr. 54, D-80799 Munich

The origin of life is located between the astronomy, geology and chemistry of early Earth and biology. Can concepts from physics help to bridge the gap between dead and living matter? Our experiments show that phase transitions, cooperative binding and non-equilibrium couplings can make headway towards understanding a stable replication and selection of the first living genetic molecules.

1. A phase transition of DNA or RNA oligomers into hydrogels is found under non-equilibrium driving. Only molecules with matching gene sequences form one hydrogel. This highly nonlinear phase transition can allow for an unusual, yet robust sequence replicator.

2. The cooperative of joining of three DNA strands implement hypercycle dynamics in sequence space. Besides providing replication under serial dilution and feeding, the hyperexponential growth make majority sequences outcompete minority sequences. By this, diversity is stabilized even under diffusional mixing.

3. Thermal gradients in porous rock implement the thermal cycling required in above experiments. Such a setting can accumulate genetic molecules, enhance their polymerization, encapsulate them by vesicle formation and drive their replication dynamics by thermal convection. The fluid interaction with a continuous feeding flow allow longer strands to outcompete faster growing short strands and drive evolution towards increasing complexity.