About ~3.8 billion years ago, there lived on Earth a small single-celled organism known as “LUCA” (last universal common ancestor). Over the next few billion years, LUCA evolved by Darwinian evolution into organisms all of the major domains of life known today. But what was LUCA, and where did it come from? We know that LUCA was probably a cell with a lipid bilayer, we know it had ribosomes that translated proteins to enable its existence, and it must have had an RNA or DNA genome that could be replicated to facilitate reproduction and evolution. Nonetheless, the emergence of LUCA from inanimate organic matter on ancient Earth cannot be explained by classical Darwinian evolution. How then, did it come to exist?
We seek to gain understanding into the emergence of LUCA by studying the self-reproduction and size expansion of RNAs. RNA molecules and their activities are a plausible driver of early life emergence because they can store information, serve as a genome, and catalyze the formation of proteins as is done by modern ribosomal RNA.
One potential breakthrough to our understanding of RNA has been the discovery that small RNAs are capable of undergoing spontaneous, energetically neutral recombination reactions in water and magnesium salts at mild temperatures to expand their lengths and diversify their sequences. We study these small RNA recombinations with both in vitro reactions (in a test tube) and computer simulations to understand how RNA reactions and networks might have contributed to the origin of life.
Our research into the origin of life is primarily inspired by the will to understand one of science’s great unsolved questions. Along the way, we are always looking for medical and technological applications of our work. Astrobiology, space exploration, aptamer therapeutics, AI, and artificial neural networks, are all examples of fields or domains where origin of life research could have practical applications.