Researchers have described how electrical energy naturally produced at the sea floor might have given rise to life.
According to the findings, which also can be thought of as the "water world" theory, life may have begun inside warm, gentle springs on the sea floor, at a time long ago when Earth's oceans churned across the entire planet.
The water world theory from scientist Michael Russell of JPL and his team says that the warm, alkaline hydrothermal vents maintained an unbalanced state with respect to the surrounding ancient, acidic ocean - one that could have provided so-called free energy to drive the emergence of life.
In fact, the vents could have created two chemical imbalances. The first was a proton gradient, where protons-which are hydrogen ions-were concentrated more on the outside of the vent's chimneys, also called mineral membranes. The proton gradient could have been tapped for energy-something our own bodies do all the time in cellular structures called mitochondria.
The second imbalance could have involved an electrical gradient between the hydrothermal fluids and the ocean. Billions of years ago, when Earth was young, its oceans were rich with carbon dioxide. When the carbon dioxide from the ocean and fuels from the vent-hydrogen and methane-met across the chimney wall, electrons may have been transferred. These reactions could have produced more complex carbon-containing, or organic compounds-essential ingredients of life as we know it. Like proton gradients, electron transfer processes occur regularly in mitochondria.
"Within these vents, we have a geological system that already does one aspect of what life does," said Laurie Barge, second author of the study at JPL. "Life lives off proton gradients and the transfer of electrons."
The new study has been published in the journal Astrobiology.
