Of Mars and Mono
Nestled in the high desert of eastern California, Mono Lake is 13 miles long, 7 miles wide and the hue of a robin’s egg. It has no outlet. In late-summer, up to 2 million eared grebes dive through its salty, alkaline water, their legs kicking up small splashes like frogs jumping from lily pads. Wilson’s and red-necked phalaropes lift off peeping, and form sinuous, shimmering flocks that, from a distance, appear suddenly as islets. California gulls bob here and there, thousands of them nesting on the actual volcanic islets at the lake’s center, where they feed their chicks slurries of brine shrimp. One of the most biologically productive lake’s on the planet, Mono feeds millions of migrating birds each year; and now, beneath its surface, another creature has been discovered that’s unlike any other life as we know it.
It was announced yesterday: NASA fellow and USGS scientist Felisa Wolfe-Simon isolated a bacteria from Mono that, in a lab, she gradually fed arsenic. Yet amazingly, the bacteria—strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria—continued to grow, incorporating this universal toxin (or so we thought) into its body in lieu of phosphorous, long considered one of six elements key to life. “This is a microbe that has solved the problem of how to live in a different way,” Wolfe-Simon told the New York Times. Her experiment suggests there may be strains of life we don’t yet recognize (or waves of life, in the past); and that, as we peer into space in search of life, we may need to take a step back, catch our breath, and then broaden our lens.
It’s important to note, though, that GFAJ-1 only “solved the problem of how to live in a different way” for us in a controlled setting. Mono Lake has a relatively high arsenic concentration (17 parts per million, at the lake's lowest level, is a lot when compared with the EPA’s standard of .01 ppm for drinking water), but GFAJ-1 doesn’t subsist on arsenic “in nature.” Nonetheless, the experiment demonstrates that a biological system/cell could “manage a weak link” (in this case, an absence of phosphorous), as chemist Steve Benner explained yesterday at a NASA press conference. The bacteria grew more slowly overall on an arsenic diet, but it managed. “It’s like if you or I morphed into fully functioning cyborgs after being thrown into a room of electronic scrap with nothing to eat,” Caleb Scharf, a Columbia University astrobiologist, told the New York Times.
Almost as remarkable, perhaps, is that, in the early 80s, Mono Lake’s ecosystem nearly collapsed. The City of Los Angeles began diverting four of Mono Lake’s five main creeks in 1941 and, over the course of 40 years, the lake dropped 45 feet, increasing in salinity to the point where its brine shrimp almost couldn’t survive. The National Audubon Society, along with the Mono Lake Committee, brought suit, and in 1983 the California Supreme Court ruled it was the state’s duty to safeguard the environment for all, even if that meant a shuffling of once-inviolable water rights. This was an unprecedented decision, a landmark for the environmental movement, and Mono's level was stabilized. Mono Lake is a windswept, austere place, but it’s anything but alien. It’s essential to birdlife and, it seems, to undiscovered wonders.
Upon hearing this news, many will look to the night skies, to Mars and beyond. But what the GFAJ-1 bacteria also signals is that we should redouble our efforts to protect the environments on this planet; obviously, we’re still getting to know them. Though this particular arsenic-tolerant “extremophile” might have survived in Mono Lake had it dropped further, Mono's brine shrimp would have died, and the birds that feed on them would have been displaced. Who knows what else might have been lost.