Extraterrestrial life could potentially arise from “deadly” substances such as radioactive metals and other materials vastly different from life on Earth.
A new study led by biologist, microbiologist, and evolutionary biologist Betül Kaçar from the University of Wisconsin-Madison has identified 270 different self-catalyzing reaction pathways, most of which do not require organic compounds.
This also suggests that the search for extraterrestrial life may need to be redirected.
The new study shows that biochemical reactions can originate from the strangest materials and conditions – (Graphic: Betül Kaçar).
“One of the main reasons researchers studying the origins of life are interested in self-catalytic processes is that reproduction itself is an example of a self-catalytic process” – the Live Science quoted Dr. Kaçar.
Self-catalysis is a type of chemical interaction that plays a crucial role in life, including life on Earth. It is believed to be a factor that helps combine the initial, lifeless “building blocks of life” into actual living organisms, and then continues to sustain that life as it reproduces and evolves.
Previously, it was thought that the “reactions leading to life” required organic compounds.
However, the 270 pathways identified by Dr. Kaçar’s team hardly require organic compounds, instead originating from some of the most “deadly” substances for Earth life, such as mercury or radioactive thorium, and rare gases like xenon…
Some pathways occur under extremely harsh conditions such as extremely high or low temperatures or pressures.
Therefore, the authors conclude there is a reasonable basis to predict that self-catalytic processes that produce extraterrestrial life could easily occur with other elements, rather than the usual “backbone” elements of terrestrial life such as carbon, oxygen, sulfur, phosphorus…
Notably, most of the 270 pathways consist of 2 reactions, with 8 of them even having 4 or more reactions. They can combine to create a large, complex chain of biochemical reactions.
Until now, searches for extraterrestrial life have often targeted “potential biosignatures”, such as evidence of the elements or compounds necessary for Earth-like life as shown through the spectra of planets: oxygen, methane, phosphate compounds…
However, the recently published results in the Journal of the American Chemical Society indicate that planets lacking these “vital factors”, or having environments that are completely alien and harsh compared to Earth life, still have the potential to host their own forms of life.
