Future work will step further and further back toward more and more simple starting material.

“Now we are working our way backwards toward the building blocks,” explains co-author Ramanarayanan Krishnamurthy of Scripps Research. “If we start with RNA and DNA nucleotides as mixtures, will they give rise to these chimeric sequences? If that works, we will try to go back further.”

When asked if this work is either ‘narrowing down’ or ‘broadening’ the question of life’s origins, Krishnamurthy explains that the study opens origin-of-life studies up to wider possibilities.

“If we started with a mixture, it is likely that the environmental conditions narrowed it down to what we see today. If you change those environmental conditions, you may end up with a different result.”

The work is focused on understanding the nature of life on Earth, but also bears relevance to NASA’s search for life beyond our planet. If you started with the same basic mixture of materials on another world, where the environment is different than the early Earth, would it lead to the same outcome?

“We can’t expect to see the types of environments we see on Earth today on other worlds,” says Krishnamurthy. “What we are doing is focusing on the extant biology on Earth and trying to extrapolate it backwards. But if you come at this question from the other side, from a systems chemistry or messy chemistry point of view, what would be the outcome if you started from the same mixture but on another planet? For instance, what happens if it’s always -20 C?”