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Credit: UCLA Center for the Study of Evolution and the Origin of Life |
Excerpt from natmonitor.com
By Justin Beach
If there was a Guinness World Record for not evolving, it would be
held by a sulfur-cycling microorganism found off the course of
Australia. According to research published in the Proceedings of the National Academy of Sciences, they have not evolved in any way in more than two billion years and have survived five mass extinction events.
According to the researchers behind the paper, the lack of evolution
actually supports Charles Darwin’s theory of evolution by natural
selection.
The researchers examined the microorganisms, which are too small to
see with the naked eye, in samples of rocks from the coastal waters of
Western Australia. Next they examined samples of the same bacteria from
the same region in rocks 2.3 billion years old. Both sets of bacteria
are indistinguishable from modern sulfur bacteria found off the coast of
Chile.
“It seems astounding that life has not evolved for more than 2
billion years — nearly half the history of the Earth. Given that
evolution is a fact, this lack of evolution needs to be explained,” said
J. William Schopf, a UCLA professor of earth, planetary and space
sciences in the UCLA College who was the study’s lead author in a statement.
Critics of Darwin’s theory of evolution might be tempted to jump on
this discovery as proof that Darwin was wrong, but that would be a
mistake.
Darwin’s work focused more on species that changed, rather than
species that didn’t. However, there is nothing in Darwin’s work that
states that a successful species that has found it’s niche in an
ecosystem has to change. Unless there is change in the ecosystem or
competition for resources there would be no reason for change.
“The rule of biology is not to evolve unless the physical or
biological environment changes, which is consistent with Darwin. These
microorganisms are well-adapted to their simple, very stable physical
and biological environment. If they were in an environment that did not
change but they nevertheless evolved, that would have shown that our
understanding of Darwinian evolution was seriously flawed.” said Schopf,
who also is director of UCLA’s Center for the Study of Evolution and
the Origin of Life.
It is likely that there were genetic mutations in the organisms.
Mutations are fairly random and happen in all species, but unless those
mutations are improvements that help the species function better in the
environment, they usually do not get passed on.
Schopf said that the findings provide further proof that Darwin’s ideas were right.
The oldest fossils analyzed for the study date back to the Great Oxidation Event.
This event, which occurred between 2.2 and 2.4 billion years ago, saw a
substantial increase in Earth’s oxygen levels. That period also saw an
increase in sulfates and nitrates, which is all that the microorganisms
would have needed to survive and reproduce.
Shopf and his team used Raman spectroscopy, which allows scientists
to examine the composition and chemistry of rocks as well as confocal
laser scary microscopy to generate 3-D images of fossils embedded in
rock.
The research was funded by NASA Astrobiology Institute, in the hope that it will help the space agency to find life elsewhere.
Source Article from http://feedproxy.google.com/~r/AscensionEarth2012/~3/_-rc5vZjJeo/scientists-discover-organism-that-hasnt.html
Scientists discover organism that hasn’t evolved in more than 2 billion years
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