Almost six decades ago, when Stanley Miller was just a 22-year-old PhD student, he and his professor Harold Urey did an experiment that became legendary in science: Miller mixed basic chemicals that were present in primordial earth and added electric sparks to stimulate a thunderstorm. The result? Miller found traces of amino acids - the building blocks of proteins.
After Miller died last year, his former student found a (scientific) treasure trove: the vials containing dried samples from his groundbreaking 1950s experiment. And when they tested the samples using today's more sophisticated equipments, they found a lot more stuff:
"We found not only did these make more of certain amino acids than in the classic experiment, but they made a greater diversity of amino acids."
Miller, using the old methods, had found five amino acids; Jeffrey Bada and his teams tracked down 22. What is more, the overall chemical yields were often higher than in the first set of experiments - the mixture appeared to be more fertile.
Professor Bada points out that today, almost all volcanic eruptions are accompanied by violent electric storms. The same could have been true on the young Earth. "What we suggest is that volcanoes belched out gases just like the ones Stanley had used, and were immediately subjected to intense volcanic lightning.
"And so each one of those volcanoes could have been a little, local prebiotic factory. And so all of that went into making the material that we refer to as the prebiotic soup."