Clues to Life on Land in SE Oregon's Warner Valley

A few days ago, I posted a Google Earth image of Warner Valley at Pathological Geomorphology. Now there's a Wired Science story on some biological research done there which may have implications for life's colonization of the earth's land surface. As these land-locked lakes fluctuate in size through the seasons, bacterial mats are subjected to cycles of submersion and and sub-aerial exposure.

“Production of [wax esters] may represent an adaptation to cross a critical evolutionary threshold, i.e. surviving dehydration and/or dessication cycles,” wrote David Finkelstein, a biogeochemist at the University of Tennessee-Knoxville, and his co-authors. “This adaptation could have facilitated bacterial migration into the earliest lakes, and aided survival in terrestrial environments.”

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When a microbe makes a wax ester from the molecules available to it, it also generates a water molecule. So, making esters could be a way of helping cells survive in environments with varying levels of moisture.

“It’s a really cool idea if it actually turns out in a concrete way that this is a way of waterproofing yourself and forestalling the loss of cellular water,” Finkelstein told Wired.com. “The first microbial mass that colonized land sure would have needed some kind of adaptation like this to make it successful.”

I've often noticed these mats in basin lakes when I've been out and about in SE Oregon, but it's cool to think they might give us some important insights into the history of Precambrian life.