Thursday, December 2, 2010

The Shadow Story of Life on Earth

My son Ethan, a molecular biologist at Princeton, just alerted me to watch the NASA news conference that will be streamed live at the NASA website:

http://www.nasa.gov/home/hqnews/2010/nov/HQ_M10-167_Astrobiology.html

Here is a link to an article in today’s Washington Post which describes the momentous discovery which has triggered a furor in the scientific community:

http://www.washingtonpost.com/wp-dyn/content/article/2010/12/02/AR2010120203102.html

And here are excerpts from the Washington Post article about the “shadow biosphere” just discovered, which show a startling resonance to the shadow stories of Austen, Shakespeare and others I have discovered, especially in terms of the process by which Wolfe-Simon found something that nobody else had done before"

“All life on Earth - from microbes to elephants and us - is based on a single genetic model that requires the element phosphorus as one of its six essential components. But now researchers have uncovered a bacterium that has five of those essential elements but has, in effect, replaced phosphorus with its look-alike but toxic cousin arsenic. News of the discovery caused a scientific commotion, including calls to NASA from the White House and Congress asking whether a second line of earthly life has been found. A NASA press conference Thursday and an accompanying article in the journal Science, gave the answer: No, the discovery does not prove the existence of a "second genesis" on Earth. But the discovery very much opens the door to that possibility and to the related existence of a theorized _"shadow biosphere"_ on Earth - life evolved from a different common ancestor _than all that we've known so far. "Our findings are a reminder that LIFE-AS-WE-KNOW-IT COULD BE MUCH MORE FLEXIBLE THAN WE GENERALLY ASSUME OR CAN IMAGINE," said Felisa Wolfe-Simon, the young biochemist who led the effort after being selected as a NASA Astrobiology Research Fellow and as a member of the National Astrobiology Institute team at Arizona State University. "IF SOMETHING HERE ON EARTH CAN DO SOMETHING SO UNEXPECTED - THAT BREAKS THE UNITY OF BIOCHEMISTRY - WHAT ELSE CAN LIFE DO THAT WE HAVEN'T SEEN YET" she said.

....Theoretical physicist and cosmologist Paul Davies, director of the Beyond Center at Arizona State and a prolific writer, is a co-author on paper. He had been thinking about the idea for a decade and had written a paper in 2005. So had University of Colorado at Boulder philosopher and astrobiologist Carol Cleland. Both asked why nobody was looking for life with different origins on Earth, and Cleland coined the phrase "SHADOW BIOSPHERE."

At a Beyond Center conference four years ago, Wolfe-Simon, then in her late 20s, proposed a way to search for a possible shadow biosphere, and it involved Mono Lake and its arsenic. "We were kicking vague ideas around, but she had a very specific proposal and then went out and executed it," Davies said. "IT DEFIES LOGIC TO THINK SHE FOUND THE ONLY EXAMPLE OF THIS KIND OF UNUSUAL LIFE. QUITE CLEARLY, THIS IS THE TIP OF A HUGE ICEBERG." _

Chemist Steven Benner of the Foundation for Applied Molecular Evolution in Florida has been involved in "shadow biosphere" research for several years, and will speak at the NASA unveiling of Wolfe-Simon's work. ….The Mono Lake discovery highlights one of the central challenges of astrobiology - knowing what to look for in terms of extraterrestrial life. While it remains uncertain whether the lake's microbes represent another line of life, they show that organisms can have a chemical architecture different from what is currently understood to be possible….."SOMETIMES I'M ASKED WHY SOMETHING LIKE THIS HAS NEVER BEEN FOUND BEFORE, AND THE ANSWER IS THAT NOBODY HAS RUN THE EXPERIMENT BEFORE," Wolfe-Simon said. "There was nothing really complicated about it - I ASKED A SIMPLE QUESTION THAT WAS TESTABLE AND GOT AN ANSWER."

Cheers, ARNIE

2 comments:

  1. A clever take on this amazing story, Arnie.

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  2. Thank you, Diana, but this one just fell into my lap, so to speak. It shows that the process of discovery is very similar in fields which might seem to have nothing in common.

    Cheers, ARNIE

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