Helen Hansma, University of California, Santa Barbara, on Tuesday presented her hypothesis that flaky layers of the mineral "mica" could have created the perfect conditions for life to form at the American Society for Cell biology's 47th annual meeting in Washington, D.C. (File Photo)

    BEIJING, Dec. 5 (Xinhuanet) -- Forget soup, forget pizza, a California biochemist says life began in a sandwich.

    Helen Hansma, University of California, Santa Barbara, on Tuesday presented her hypothesis that flaky layers of the mineral "mica" could have created the perfect conditions for life to form at the American Society for Cell biology's 47th annual meeting in Washington, D.C.

    "Mica is like a massive sandwich with millions of layers of mineral sheets, which would be the bread," Hansma said. "The nooks and crannies between the bread may have jump-started the formation of life's chemicals and protected them. It's like a giant potluck of chemistry."

    The competing chemical soup model claims life formed in a sea of chemicals, but Hansma said it does not outline a good place for molecules to react with one another.

    Although the "pizza" postulates does, stating that molecular toppings formed on the surface of crusty minerals, Hansma said it falls short of linking basic biological chemicals together to form ribonucleic acid (RNA) and other crucial components.

    To address these shortcomings, Hansma merged the soup and pizza ideas to create her sandwich hypothesis.

    "The mineral surfaces between mica layers create reaction surfaces, the pre-biotic soup gives you the reactants and the tiny spaces shelter the whole process," she said. "Energy to power [the chemical reactions] would have come from shifting layers of mica, perhaps from something like ocean currents or sunlight."

    She said mica — which is rich in potassium — might also explain why our bodies rely so heavily on potassium instead of other elements.

    Hansma said early experiments her team has performed back up the sandwich idea, but cautioned that significant work lies ahead before she can make the hypothesis appetizing to other scientists.