UV Light Aided In Igniting Life On Earth

People have been warned of the dangers of exposure to ultraviolet radiation, as it is a known hazard to life. However, it seems that despite such precaution, it seems that the energy provided by the Sun has been essential in driving life on Earth.

Live Science reported that before life began on the planet, the main source of energy has been the radiation from the Sun -- like the way it is today. However, the prebiotic world is poor in oxygen, and it needs something more. The Sun's solar energy may have been the one to provide a sort of jolt to transform simple organic molecules into more complex ones that then became the building blocks of biology.

This theory was raised by two University of Colorado at Boulder authors, Rebecca Rapf, a doctoral candidate in physical chemistry, and her adviser, Veronica Vaida. The study, published in the US National Library of Medicine, is said to be supported by a NASA Earth and Space Science Fellowship.

The study stated that the lack of oxygen in the early atmosphere resulted to more high-energy ultraviolet radiation from the Sun that reached the surface of the Earth, compared to how it is today. That said, the component of sunlight, despite being destructive to certain bio-molecules, could still have been useful to early life chemistry.

"Even if you destroy a molecule, it is broken into smaller, very reactive chunks that readily undergo additional reactions, recombining to form larger high-energy molecules," Rapf explained.

What intrigued the researchers most of all are oxoacids, which are oxygen-ladled acids that are considered key metabolic pathways in life today. An example of such is the pyruvic acid.

According to Space.com, when pyruvic acid is dissolved in water and illuminated in ultraviolet light, it reacts to make larger molecules with higher yields. This behavior is said to be similar to the oxygen-limited conditions that would have been found on early Earth.

However, pyruvic acid is just a limited example. Rapf explained that while sunlight was needed to build bigger molecules, these said molecules should still be stable enough to be able to exist in the environment.