Dieter Braun, Ph.D.

SCOL Project: Reconstructing Early Functions of Life

We will reconstruct in the lab the first cycles of Darwinian evolution. Our bottom-up approach reconstructs the boundary conditions of early Earth to gather and drive the first living molecules. We will focus on persistent replication, emergence of a phenotype and selection to overcome central hurdles in our understanding of the origins of life. The approach can be compared to an engineer who designs a chemical plant to implement a specific chemical reaction.

It has become more clear how the first molecules of life could have emerged. For physics, the next step is to implement conditions under which these genetic molecules can polymerize efficiently to oligonucleotides of sufficient length and trigger the initial replication cycles. We have shown that replication can be aided by accumulation from temperature gradients, water-air interfaces and gelation processes. We will focus on mechanisms that are able to prefer the replication of molecules better at higher concentrations. This will create a self-selection of random sequences into a phenotype of similar and chiral pure sequences.

Life persists far from equilibrium. Nonequilibrium boundary conditions offer the vital supply of negentropy for replication and selection. For nonequilibrium conditions to be fast and effective, they have to be implemented at the size scales of life. We aim for defined situations that implement ordered, but also messy, molecular nonequilibria at the micrometer scale. This scale is essential since it allows efficient diffusional mixing. But in this micrometer regime, analytical methods become demanding when experimental volumes are merely microliters in size. We follow an exploratory paradigm. But since we will describe our findings using finite element methods, we will be able to simulate lab experiments beforehand, speeding up the progress to tune the boundary conditions to the molecular needs of early life.

Bio:
Dieter Braun is a professor in the department of physics at the Ludwig Maximilians University of Munich. He received a diploma and Ph.D. in physics, working with Peter Fromherz at the Max Planck Institute for Biochemistry. After working as a DFG Scholar at the Rockefeller University with Albert Libchaber, in Munich he led his own Emmy Noether group on biomolecule thermophoresis and thermal trapping, leading to the award-winning startup company NanoTemper (140 employees), founded by two of his first Ph.D. students. The company uses thermophoresis to quantify biomolecule binding in complex liquids and has won the Deutsche Innovationpreis, the Deutscher Gründerpreis and, in 2019, the Technology Transfer Prize of the German Physical Society. Braun has received the Klung-Wilhelmy Weberbank prize, Germany’s largest monetary biannual award for physicists younger than 40. He initiated the Origin of Life Initiative Munich in 2015 and organized and leads the Collaborative Research Center Emergence of Life (www.emergence-of-life.de), funded by the DFG. He coordinates the molecular evolution section in the Origins Cluster, received an ERC Advanced Grant in 2018 and is the spokesperson of the Center for NanoScience.