- A chance discovery of previously unimaginable
life forms in Australian petroleum drilling samples could trigger a new
debate about extraterrestrial life. A Queensland geologist said yesterday
that creatures far smaller than anything yet discovered had multiplied
under her microscope.
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- These creatures were of the same size
as the disputed 'nanobacteria' found in fossil traces in a meteorite known
to have come from Mars.
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- The Nasa team that three years ago claimed
evidence for former life on Mars is expected shortly to announce that they
have found similar fossil traces inside a second meteorite from Mars. But
other scientists have claimed that the Nasa team were seeing something
caused by geology, not biology, and that there was no evidence for life
forms 10 times smaller than the smallest known microbes on Earth.
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- Philippa Uwins of the University of Queensland
could be about to change all that. She revealed yesterday that tiny filaments
in her mineral samples had multiplied, and that she had detected DNA in
them.
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- 'What I have got is very tiny organic
structures which mimic life and which are composed of carbon, oxygen and
nitrogen. They are non-crystalline, so we have discounted all other possibilities,'
she said.
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- 'Our conclusion, based on the evidence
that we have, is that these are living biological organisms. If they are
not, nobody has yet been able to give me an alternative suggestion.'
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- The discovery happened during research
for an offshore petroleum prospecting company. She had been looking at
a clay mineral called illite, which has submicroscopic fibres. It was a
microbiologist colleague who said to her: 'It looks like you have fungus
growing on your samples.'
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- She went back to her slides and saw spore-like
structures that reminded her of germinating bacteria, and filamentous growths
that looked like fruiting fungal bodies. Geneticists are now trying to
'read' the DNA blueprint within the discoveries.
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- Other scientists have claimed to have
found ultra-small bacteria in rocks but until now the consensus has been
that creatures that small would have no room for the machinery of replication.
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- Dr Uwins does not use the word 'nanobacteria'
because she doesn't know her discoveries' evolutionary development. She
has called them 'nanobes'.
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- Monica Grady, of the Natural History
Museum, in London, has been involved in the extraterrestrial life debate
for the last three years. She says she has yet to read the details of the
discovery.
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- 'These things grew all over her lab surfaces
and colonised her instruments and started eating her fingerprints. That
doesn't mean anything much at all, it just means the rocks had bacteria
in them, which rocks do. It's well known that fungi grow on rocks,' Dr
Grady said yesterday. 'We have got a lot more information but I don't think
we have any more knowledge.'
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