Making Life From Scratch

There is a hypothesis that there was a world filled with life based on RNA which predates our current world where life is based on DNA and protein. Given this hypothesis, this experiment in trying to make life from scratch, based on RNA, is an interesting one indeed.

For the first time, scientists have synthesized RNA enzymes – ribonucleic acid enzymes also known as ribozymes – that can replicate themselves without the help of any proteins or other cellular components.

What’s more, these simple nucleic acids can act as catalysts and continue the process indefinitely.
The researchers began with ribozymes known to occur naturally, and put these in a growth medium, heated them and allowed the ribozymes to replicate until they had exhausted their fuel – usually within an hour.

The team then extracted a random subset, and put them in a new medium: ribozymes then competed with each other to consume as much of the medium as possible.

Eventually more successful ribozymes came to dominate the culture, and as the process continued, the ribozymes – undergoing evolution – grew in complexity, blindly finding solutions that made them more successful.

“The key thing is it replicates itself, and passes information from parent to progeny down the line,” Joyce told Cosmos Online.

“There’s roughly 30 bits of information passed. Some functions are more fit than others, and those that are more fit ‘breed’ more, and are perpetuated more efficiently, and so it goes Darwinian.”

The ultimate goal is to create genetic systems that behave like life, and are for all intents ‘life’ as we know it, but arose without using biological systems.

“The aim is to create systems that have inventive capabilities, that can develop novel solutions to challenges posed by the environment. But that we don’t have yet,” he said.

“What we do have is a self-sustained chemical system that undergoes Darwinian evolution.
They are synthetic genetic systems, and they are evolving. But they’re not living because they don’t yet show the capacity to invent a whole cloth of functions.

(Emphasis mine.)


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