Scientists attempt to re-create how life began
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How did life on Earth begin?
Scientists in a lab used a powerful laser to re-create what might have been the original spark of life.
The researchers zapped clay and a chemical soup with the laser. It simulated the energy of a speeding asteroid smashing into the planet. They ended up creating what can be considered crucial pieces of the building blocks of life.
The findings do not prove that this is how life started on Earth. That was about 4 billion years ago. Some scientists were unimpressed with the results. But the experiment does bolster the long-held theory.
The study was published in the journal Proceedings of the National Academy of Sciences.
The laser-zapping produced all four chemical bases needed to make RNA. It's a simpler relative of DNA, the blueprint of life. From these bases, there are many still-mysterious steps that must happen for life to emerge. But this is a potential starting point.
Scientists have been able to make these RNA bases other ways. They use chemical mixes and pressure. But this is the first experiment to test the theory that the energy from a space crash could trigger the crucial chemical reaction.
Researcher Svatopluk Civis said the scientists used a laser almost 500 feet long. It zapped the chemical soup with an invisible beam. The power was intense and concentrated. Civis said that for less than a billionth of a second, it was equivalent to the output of a couple of nuclear power plants. It generated heat of more than 7,600 degrees Fahrenheit.
Some of the earliest life on Earth seemed to coincide with a period called the Late Heavy Bombardment. That's when the solar system's asteroid belt was bigger. Stray space rocks hit our planet more often, said study co-author David Nesvorny. He is a planetary scientist at the Southwest Research Institute.
At the time, asteroids were bombarding Earth 10 times more frequently than before or after.
Outside experts were divided about the importance of the experiment.
There also is an alternative theory of early life on Earth. It says that microbes arrived here from space. They were aboard a comet or an asteroid. That could have been a sort of seed theory of life.
Civis' work bolsters what would instead be a fire theory of life. It is a theory of both creation and destruction.
Critical thinking challenge: How is this experiment different than others seeking the origins of life?