In a message dated 1/17/00 1:26:53 AM Dateline Standard Time,
sejones@iinet.net.au writes:
<< http://dailynews.yahoo.com/h/nm/20000112/sc/space_mars_3.html
Yahoo! ... Wednesday January 12 ... Did Bacteria Survive Trip
From Mars? ATLANTA (Reuters) - Astronomers reported on
Wednesday they had found a tough but peaceful pair of bacteria
that might have been able to survive the arduous trip from Mars,
back when the Red Planet could have supported life. ... The
bacteria -- Bacillus subtilis (wild) and Deinococcus radiodurans R1 -
- are resistant to high speeds, extreme heat and radiation... [It
should be possible to tell if these bacteria are primitive, by
subjecting them to a molecular cladistic test. If they are at or near
the root of the presumed bacterial family tree, then it is possible
that they originated from Mars. But if they are not then it is more
likely they later adapted to life in extreme environments. >>
Actually, the genomes for both these bacteria have been sequenced
and they don't look any more primitive than any other eubacteria.
Deinococcus is pretty interesting, however. It has this tremendous
ability to quickly put all its DNA back in the correct order after you blast
it into pieces with radiation. It turns out it doesn't seem to have any
special
enzyme to do this. It simply has every DNA repair scheme found
in the bacterial world all packaged into the same cell.
Mike
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