Major rewriting of textbooks to be needed even more evidence. But NASA discovery rewrites at least some of their theorems.
They taught us is that life from simple organisms and man-ending works by some chemical rules. Carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus should be the basic building blocks that make should work on Earth.
Changing the definition of life?
But just had. California bacterium GFAJ-1 shows that we have yet to be wrong. A wrong is also our books and textbooks. They argued that phosphorus must be part of DNA and RNA that is essential for the existence of life itself. It is not. They might even arsenic.
“The definition of life is being extended,” he declared to Ed Weiler, NASA’s science mission directorate of the U.S. office. “If we continue to look for evidence of life in our solar system, we must now think in much broader context. We also think about life, what we do not know. “
Arsenic is chemically very similar to phosphorus. But the important thing is that for life as we know it yet, was fatally poisonous.
Precisely because of its similarity with phosphorus interferes with metabolism and subsequently killed. Bacterium from the U.S. Mono Lake is no exception. Can the toxic environment superslaného arsenic lake not only survive, but also make use of arsenic in their favor.
“We know microbes are able to breathe arsenic. But we found a microbe that makes something entirely new – to expose their own part of the arsenic, “commented the key biological discovery of the author Felis Wolfe-Simon.
DNA with arsenic
This geobiologist and specialist in astrobiology studied in the laboratory Gammaproteobacteria GFAJ-1, originating from Mono Lake.
Phosphorus completely removed and replaced him with arsenic in artificial conditions. Despite the assumption organisms perish, be developed, although about 60 percent slower, but grow. Not only that, phosphorus, bacteria and subsequently exchanged arsenic in its DNA, cell membranes and the formation of proteins.
“It’s the first time in history when we showed a similar chemical substitution for DNA,” he told New Scientist Philippe Bertin from the University of Strasbourg. “Perhaps this is a remnant of our ancient ancestors metabolism, which was replaced during evolution, because phosphorus is more stable and less toxic. “
Life pretty unknown
These bacteria able to survive more than a year and still live. They reportedly doing quite well.
The consequences of this finding are taking a huge, when it is at first glance may look like.
Even our first speculation about the possibility of saying that life or chemistry of life could develop on Earth several times and the ability of bacteria from Mono proves it. Because she works completely differently than we have so far only seen elsewhere, but also expected.
A second possibility is that life is simply more complicated, more capable and adaptable than scientists have yet managed to even imagine. But this does not mean that evolution has taken place several times in Earth’s history.
The third result is that the search for extraterrestrial life in outer space, we can build on completely false assumptions.
Our spacecraft and robots seek traces of life, what we still seemed normal. But he can operate under completely different rules. It could even be that what seems normal to us, is merely the exception of space.
California’s Mono Lake.
Additional years of work
“The idea of an alternative biochemistry is common in science fiction,” recalled Carl Pilcher, director of the Institute Astrobiologického NASA. “Until now, however, was the life of using arsenic as their only building block hypothesis. But now we know that such a life there.”
In its discovery Felis Wolfe-Simon is now awaiting us around thirty years of work, to find out what was really bizarre for arsenic bacteria going. And whether this occurs in the wild and why.