At some point on early Earth, no biological life existed. Then, at a critical juncture, a combination of minerals, chemicals and ultraviolet light gave rise to the first biology. But how that transition occurred has long been a mystery.
In pursuit of an answer, John Sutherland, group leader of the Medical Research Council’s Laboratory of Molecular Biology in Cambridge, U.K., focuses on the point at which inorganic materials became biological molecules and how biology continued to evolve after that moment.
Sutherland and his group broke crucial new ground in 2009 by discovering a process by which the building blocks of RNA can be created through
chemistry. By re-creating prebiotic conditions and working with the chemistry thought to be present on early Earth, Sutherland filled a gap in origins-of-life theory and bolstered the hypothesis that RNA was the key informational molecule at the origin of life.
Now, extending those findings, Sutherland works to identify specific chemicals that both could have existed on early Earth and had potential to give way to biology. Hydrogen cyanide, found throughout interstellar space and in the atmosphere of moons within our solar system, is of central focus. In the presence of various minerals and ultraviolet light, explains Sutherland, hydrogen cyanide could have triggered a sequence of chemical events that resulted in the first biology.
To test this theory, Sutherland traces reaction pathways from hydrogen cyanide to the emergence of amino acids — the components of nucleic acids and the building blocks of membrane-folding molecules — all through very similar chemical processes.
“We’re beginning to accumulate a substantial body of evidence that implicates chemistry based on hydrogen cyanide at the origins of life,” says Sutherland. “So a highly toxic compound to present-day life nevertheless may have contributed all the elements needed to make the building blocks that assembled at the dawn of life.”