Water cycles in a Hadean CO2 atmosphere drive the evolution of long DNA

Abstract Dew is a common form of water that deposits from saturated air on colder surfaces. Although presumably primordial Earth, its potential involvement in the origin life early replication has not been investigated detail. Here we report it can drive first stages Darwinian evolution for DNA and RNA, by periodically denaturing their structures at low temperatures second promoting long strands over short, faster replicating ones. Our experiments mimicked partially water-filled rock pore probable CO 2 atmosphere Hadean Earth. Under heat flow, continuously evaporated recondensed as acidic dew droplets created humidity, salt pH cycles match many prebiotic chemistries. In low-salt low-pH regimes, melted 30 K below bulk melting temperature, whereas longer sequences preferentially accumulated droplet interface. an enzymatic to mimic sped-up RNA world, more than 1,000 nucleotides emerged. The was biased conditions initial short ATGC evolved into AT-rich with repetitive structured nucleotide composition.