Freethought & Rationalism Archive

Coragyps · 03-10-2002, 04:23 PM

Walt Brown's <a href="http://www.creationscience.com/onlinebook/index.html" target="_blank">incisive scholarship</a> has yielded this little gem:

Quote:

. “Some different microbial species, derived from samples of rocks and [two] meteorites, have been cultured, cloned and classified by 16S rDNA typing and found to be not essentially different from present day organisms; they also appear sensitive to growth inhibition by specific antibiotics.” Giuseppe Geraci et al., “Microbes in Rocks and Meteorites,” Rendiconti Accademia Nazionale dei Lincei, Vol. 12, No. 9, 2001, pp. 51-64.

However, the bacteria recovered and cultured from the meteorites were sufficiently different from modern strains to rule out contamination. Many other steps were taken to prevent contamination.

“Bruno D’Argenio, a geologist working for the Italian National Research Council, and Giuseppi Geraci, professor of molecular biology at Naples University, identified and brought back to life extraterrestrial microorganisms lodged inside 4.5 billion-year-old meteorites kept at Naples’ mineralogical museum.” Rossella Lorenzi, “Scientists Claim to Revive Alien Bacteria,” Discovery News, <a href="http://www.discovery.com," target="_blank">www.discovery.com,</a> 10 May 2001.

This is a footnote somewhere in his unpaginated web version of In the Beginning referring to a claim that 78 kinds of bacteria were cultured from a meteorite. (I didn't realize that there was more than one bacteria "kind"..

)
I'll bet that the actual article says the meteorite lay around in a cowpasture for years before being collected, but could anyone find the article (and read Italian) just to see? Discovery.com only archives for a couple of weeks.
Fairly cool that it's published by a society that Galileo once belonged to -

[ March 10, 2002: Message edited by: Coragyps ]</p>

lpetrich · 03-13-2002, 11:37 AM

What they'd sequenced was the gene for 16S rRNA, one of the RNA molecules found in ribosomes, which are protein-assembly sites. The 16S refers to the molecule's size. Ribosomal RNA's are often used to construct family trees, because they are ubiquitous and slow-evolving.

Now for the brass tacks. I'm not sure what they meant by "sufficiently different"; I have several serious questions:

* How complete was their sequence?

* Where does this sequence fit in the tree of the hundreds of known ribosomal-RNA sequences?

* Does the sequence fit among groups of bacteria often found in soil? Or does it branch off very deeply?

* Were other known genes found?

If these bacteria were Earthly contaminants, then these bacteria would have genes close in sequence to some known bacteria.

However, if they were extraterrestrial, then their gen sequences would have to have diverged very early.

crocodile deathroll · 03-13-2002, 12:04 PM

So it is just cosmic bacteria! that sure is a big comedown from Close Encounters of the Third Kind and Alien

Quote:

Originally posted by lpetrich:
<strong>What they'd sequenced was the gene for 16S rRNA, one of the RNA molecules found in ribosomes, which are protein-assembly sites. The 16S refers to the molecule's size. Ribosomal RNA's are often used to construct family trees, because they are ubiquitous and slow-evolving.

Now for the brass tacks. I'm not sure what they meant by "sufficiently different"; I have several serious questions:

* How complete was their sequence?

* Where does this sequence fit in the tree of the hundreds of known ribosomal-RNA sequences?

* Does the sequence fit among groups of bacteria often found in soil? Or does it branch off very deeply?

* Were other known genes found?

If these bacteria were Earthly contaminants, then these bacteria would have genes close in sequence to some known bacteria.

However, if they were extraterrestrial, then their gen sequences would have to have diverged very early.</strong>

lpetrich · 03-15-2002, 09:48 AM

So true. And the antibiotic sensitivity is an indirect indicator of the microbes' biochemistry; these substances work by blocking various enzymes, something like a key that gets stuck in a lock because it does not quite fit. This requires that there be enzymes with some suitable shapes, which is a far-fron-trivial requirement. Which is also consistent with these microbes being Earthling microbes.

Coragyps · 03-15-2002, 10:04 AM

That was Walt's point, I think: these microbes were from Earth, got blasted out into space during the 20-mile-per-hour continental drift of his "hydroplate" Flood lunacy, and returned to Earth in meteorites. Of course, he says that the entire asteroid belt and all the comets came from this same event. It seems to me they would all be in Earth-crossing orbits if they had originated that way, and perhaps even have isotopic compositions like Earth, but hey, what do I know about True Creation Science (TM)?

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03-13-2002, 11:37 AM	#2
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	What they'd sequenced was the gene for 16S rRNA, one of the RNA molecules found in ribosomes, which are protein-assembly sites. The 16S refers to the molecule's size. Ribosomal RNA's are often used to construct family trees, because they are ubiquitous and slow-evolving. Now for the brass tacks. I'm not sure what they meant by "sufficiently different"; I have several serious questions: * How complete was their sequence? * Where does this sequence fit in the tree of the hundreds of known ribosomal-RNA sequences? * Does the sequence fit among groups of bacteria often found in soil? Or does it branch off very deeply? * Were other known genes found? If these bacteria were Earthly contaminants, then these bacteria would have genes close in sequence to some known bacteria. However, if they were extraterrestrial, then their gen sequences would have to have diverged very early.

03-15-2002, 09:48 AM	#4
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	So true. And the antibiotic sensitivity is an indirect indicator of the microbes' biochemistry; these substances work by blocking various enzymes, something like a key that gets stuck in a lock because it does not quite fit. This requires that there be enzymes with some suitable shapes, which is a far-fron-trivial requirement. Which is also consistent with these microbes being Earthling microbes.

03-15-2002, 10:04 AM	#5
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	That was Walt's point, I think: these microbes were from Earth, got blasted out into space during the 20-mile-per-hour continental drift of his "hydroplate" Flood lunacy, and returned to Earth in meteorites. Of course, he says that the entire asteroid belt and all the comets came from this same event. It seems to me they would all be in Earth-crossing orbits if they had originated that way, and perhaps even have isotopic compositions like Earth, but hey, what do I know about True Creation Science (TM)?

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