“Reproducing catalytic micelles as early nanoscopic protocells capable of Darwinian evolution”
Speaker: Doron Lancet, Weizmann Institute of Science
Date: Wednesday, May 22, 2024
Time: 2:00 – 3:30pm
Location: ISB 102
To help fathom the paths for protocellular complexification en route to LUCA, we employed the GARD* model, which is based on the laws of experimental chemistry and is computer simulatable. When applied to heterogeneous micellar assemblies of amphiphilic lipids, utilizing chemical formalisms of mutually catalytic networks, we observe that when the assembly attains specific compositions (“composomes”), the protocell undergoes homeostatic growth via new monomer accretion or synthesis, leading to reproduction with mutations upon fission. This permits natural selection and Darwinian evolution to emerge at a very early stage of life’s origin, allowing graded molecular and supramolecular complexification all the way to the bacterial-like Last Universal Common Ancestor (LUCA). In other words, while complexity of individual molecules and of the protocell’s composition gradually increases, this molecular ensemble preserves the essential property of catalysis-driven effective reproduction under selective pressures all the way to the much later appearance RNA and ribosomes. Finally, we point out that unlike biopolymer-harboring vesicular protocells, micellar protocells can withstand high levels of exogenous chemical diversity and extreme environmental conditions, enhancing the realism of planet-scale micellar life emergence.
*Graded Autocatalysis Replication Domain
About the Speaker:
Doron Lancet is an Israeli human geneticist. He established and headed until recently the Crown Human Genome Center at the Weizmann Institute of Science, and in parallel studied life’s origin for 30 years.
Recording of the talk: