NASA discovery ‘expands the definition of life’

3 Dec 2010

Life on earth will never be the same again – at least for NASA scientists, who have revealed a discovery that changes the fundamental understanding of what enables life on our planet.

The US space organisation announced recently that it had a atrobiological research revealation discovery to reveal and last night told the world that tests in the harsh environment of Mono Lake, California, US, had yielded discoveries that were almost out of this world.

The research uncovered the first micro-organism on Earth that was able to thrive and reproduce using the toxic chemical arsenic instead of phosphorus.

Phosphorus not essential for life

Phosphorus (along with carbon, hydrogen, nitrogen, oxygen, and sulfur) was previously thought to be an essential element to all living things, as it is a component of DNA (deoxyribonucleic acid), RNA (ribonucleic acid) and ATP (adenosine-5′-triphosphate) – the structures that carry genetic instructions for life – and is considered an essential element for all living cells, but this new discovery turns that theory on its head and invites new avenues of thought.

“The definition of life has just expanded,” said Ed Weiler, NASA’s associate administrator for the science mission directorate of NASA’s Washington HQ.

“As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it.”

Rewriting the text books

NASA believes the newly discovered microbe, strain GFAJ-1 – a member of a common group of bacteria, the Gammaproteobacteria – is significant enough to change biology textbooks and expand the scope of the search for life beyond Earth.

“We know that some microbes can breathe arsenic, but what we’ve found is a microbe doing something new – building parts of itself out of arsenic,” said Felisa Wolfe-Simon, a NASA astrobiology research fellow in residence at the U.S. Geological Survey in Menlo Park, California, and the research team’s lead scientist. “If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?”

The Mono Lake site, where the find was made, was researched due to its unusual chemistry, especially its high salinity, high alkalinity, and high levels of arsenic.

The research is published in this week’s edition of Science Express.

For more detailed information and video of the find, click here.