Leslie Orgel, head of the Chemical Evolution Laboratory at the Salk Institute, has died. Orgel pioneered the theory that RNA preceded DNA as a replicating molecule. At the time of his death his work was focused on searching for a precursor to RNA

He was also one of the first to suggest that life on Earth might have been seeded by extraterrestrials. His name is attached to Orgel’s rules:

“Whenever a spontaneous process is too slow or too inefficient a protein will evolve to speed it up or make it more efficient.”

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“Evolution is cleverer than you are.”

LA Times obituary

Salk Institute statement

The Scientist obituary