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Looking at Life as We Know It

Posted by | November 22, 2008

Hard-working graduate students do much of the nitty-gritty fieldwork in geology.  Toiling outdoors each summer, the young folks can look forward to toiling in the laboratory during the school year.

As a student I studied gold-bearing hot springs in California, sampling the sulfur-belching waters when the day’s highs were around 103 degrees. It was hellish, but also quite an adventure, followed up by long days in the lab in the winter measuring the water’s unusual chemistry.

Despite my close association with gold, I didn’t grow rich. Indeed, I barely kept my bills paid during my years as a graduate student. But graduate students in science get a great education. That’s what keeps the professional system going strong and grad students toiling around the clock.

Carol Turse is a hard-working graduate student at Washington State University who is studying truly odd life forms in an unusual lake in British Columbia. And some of the most intriguing parts of the work Turse is doing relate to life on Mars.

Here’s the story.

Pavilion Lake, B.C., is exceedingly clear and cold. Life in the lake is not composed of the usual plants and animals, but of clumps of simple green cells known as stromatolites. If you think of chunky, green scum, you’ve envisioned stromatolites well enough.

These elementary organisms are among the oldest life form on Earth. They’re crucial characters in the history of life on Earth because they created the oxygen we animals depend on in the air around us. Strange though it may seem, many billions of years ago, the Earth’s atmosphere didn’t have oxygen gas in it. The oxygen that we need in each breath came about from the patient work of stromatolites over immense stretches of time. Like all plants, stromatolites produce oxygen as a by-product of their lives – much to our benefit.

All geologists are familiar with fossil stromatolites. But I hadn’t held a living stromatolite in my hand until I met Turse because “normal” plants generally out-compete stromatolites hands down, so they just aren’t around us.

Why doesn’t Pavilion Lake have normal vegetation and fish? There’s no certain answer. But the lake is geologically young, created as the great glaciers of the Ice Age melted. And it’s pretty isolated. In any event, odd life forms flourish in the lake.

In the shallow areas of Pavilion Lake the stromatolites look a bit like green cottage cheese. In the middle depths they form artichoke-like structures. At the deepest levels the stromatolites are balls. Scientists don’t know the whys and wherefores of these variations.

Pavilion Lake is a study site for NASA research and training because it’s full of only the simplest life around. NASA is interested in possible life on Mars because the agency is planning manned visits to the Red Planet. If Martian life ever existed – or if it still does below the surface – it might be something like Earth’s clumpy stromatolites.

While Turse has been up to her elbows in odd life forms in British Columbia, her academic adviser, WSU geologist Dirk Schulze-Makuch, has also been busy. He’s headed to Trinidad this winter to take samples of other simple yet exotic life forms, namely those that live in a natural asphalt lake.

In a few places on Earth, lakes are thick pools of mud and petroleum chemicals. Any creature, no matter how simple, that can live in natural asphalt is interesting to science. Beyond that, the asphalt lakes are warm versions of some roughly similar parts of our solar system, like Titan – a moon of Saturn.

Titan is made of natural gas, also known as methane. Temperatures on Titan are not like Trinidad, but instead are colder than 250 degrees below zero.

“Methane is a liquid at those temperatures, and it ‘rains’ methane on Titan,” Schulze-Makuch  said. “The role water plays on Earth is played by those chemicals on Titan.”

Although the temperatures are different, the materials of Titan are roughly like those of Trinidad’s asphalt lake, hence Schulze-Makuch’s interest.

Both Turse and her advisor clearly relish ideas that are out-of-the-box. Geology isn’t just about gold mines anymore.