Scientists looking for clues to the origins of life on Earth have discovered new life forms right here in Sonoma County that may shed light on how life evolved — and how it might be detected elsewhere in the universe.
A three-year study of alkaline ponds at The Cedars, a vast but remote serpentine area north of Cazadero, has uncovered microorganisms never before detected, existing in the kinds of harsh conditions believed to reflect those that first gave rise to life, scientists say.
Researchers hope studying these unique microbes and how they function may impart information about the biochemical reactions that imbued inorganic substances on early Earth with the spark of life.
"In the next few years, we're going to know a lot about these organisms, and that, I think, will stimulate a lot of thinking in these kinds of areas — both in the origins of life and in the limits of life," said Kenneth Nealson, a professor with the University of Southern California's Wrigley Institute who participated in the research published last month.
Its very appearance hints at the insights that might be yielded by The Cedars into how primitive or even extra-terrestrial life began and functioned in a hostile, anaerobic environment.
Terms like "unearthly," "other-worldly" and "moonscape-like" have been used to describe the dramatic, rugged terrain located off a winding, private dirt road that crosses Austin Creek a half-dozen times and passes through a series of locked gates.
Squint, and it's easy to imagine the raw, barren scarp that rises a thousand feet above the headwaters to Austin Creek existing somewhere on another planet. A Mars rover would look at home against its reddish hues and crumbling scree.
Below the sheer ridgeline, white crusted ponds lined with cream-colored silt, and "mineral falls" coated with thick, glistening yellow evoke the kind of primordial soup from which the first creatures on Earth might have emerged.
During summer months, the dry, rocky creek bed reveals spring-fed pools encrusted with fragile calcium carbonate structures and terraced formations that contribute to the strangeness of the place.
"You really do feel like you're somewhere different — you've been transported," said Michael Cohen, an associate professor of biology at Sonoma State University, who is conducting his own studies of microorganisms from springs for potential use in biofuel production.
"I think it's about the most extraordinary place in the county," said Ralph Benson, executive director of the Sonoma Land Trust, which owns a small chunk of it.
What differentiates the isolated region from most of what surrounds it is the massive outcropping of serpentine rock on which it's located, the result of a mineral called peridotite that got jammed up onto the continent at the boundary of moving tectonic plates tens of millions of years ago. Peridotite, a key constituent of the planet's mantle, is more commonly found many miles beneath the earth's crust.
Peridotite is unstable, producing serpentine when it interacts with water under pressure. This interaction also releases calcium bicarbonate, methane, hydrogen and high pH fluid like that which bubbles up through the rock at The Cedars, accounting for the ultra-alkaline ponds and calcium carbonate formations.
But these springs otherwise appear to lack essential elements for life as we know it, like oxygen, salt in any real quantity and other electron acceptors that would offer potential for conversion of energy, scientists say.