Life on Earth probably started as a hiccup rather than roar

A new research has looked into the origins of Earth and claimed that nearly 4 billion years ago, life on the planet probably started as a hiccup rather than a roar.

Template-assisted replication, which helps polymers grow longer while passing on sequences from generation to generation, could have enabled jump from monomers to self-replicating polymers.

However, with no fossil record to check from those early days, it's a narrative that still has some chapters missing.

Now, a new model proposes a potential mechanism by which self-replication could have emerged. It posits that template-assisted ligation, the joining of two polymers by using a third, longer one as a template, could have enabled polymers to become self-replicating.

Lead researcher Alexei Tkachenko at Brookhaven National Laboratory said that they tried to fill this gap in understanding between simple physical systems to something that can behave in a life-like manner and transmit information.

The model switches between "day" phases, where individual polymers float freely, and "night" phases, where they join together to form longer chains via template-assisted ligation. The phases are driven by cyclic changes in environmental conditions, such as temperature, pH, or salinity, which throw the system out of equilibrium and induce the polymers to either come together or drift apart.

One limitation of the model that the researchers plan to address in future studies is its assumption that all polymer sequences are equally likely to occur.

Author Sergei Maslov Maslov and Tkachenko's model fits into the currently favored RNA world hypothesis, the belief that life on earth started with autocatalytic RNA molecules that then lead to the more stable but more complex DNA as a mode of inheritance.

The study is published in The Journal of Chemical Physics.