Origin of the RNA World: the Fate of Nucleobases in warm little Ponds
Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and then polymerize in favorable environments on the early Earth. At this time enormous influxes of meteorites and interplanetary dust delivered nucleobases and other complex organic molecules to the surface. Delivery to warm little ponds (WLPs) opened the possibility for polymerization into RNA by means of wet and dry cycle of any nucleotides that would have formed, in these environments. In this talk I will first different suggested environments for the origins of life. I then discuss our work on formation of nucleobases within planetesimals that are the meteorite parent bodies. We have recently gone further to build a comprehensive physical model for the fate of nucleobases in WLPs on the early Earth (PNAS 2017) . Here we examine in detail the various kinds of destructive processes such molecules undergo. Nevertheless, our results show that RNA polymers could have built up quickly and likely appeared in thousands of ponds ~ 4.2 billion years ago.
Ralph Pudritz ist Professor am Department für Physik und Astronomie an der McMaster University in Hamilton und derzeit Visiting Fellow am CAS.