View Full Version : deep-sea hydrothermal vents -origin of life?
10-18-1999, 07:13 PM
I haven't read this stuff in detail.It's been in science news for a few years. These researches claim an important role for H2S and the bacteria that handle it, in thermal vents. By now books have been written, such as "The Deep Hot Biosphere" by Thomas Gould. That book has little related to speculation about the origins of life, mostly proven facts.
But, what have you learned, from other papers?
Some links: http://taurus.ubishops.ca/~judy/symb.htm
Most of the stuff is explained in that link….
Other stuff, ocean ridges, etc, related but not as astounding to read:
Karen Von Damm
A professor at the University of New Hampshire, Karen is a geochemist. She studies the chemistry of water sampled from the vents. With graduate student Alison Bray, she stays up all night, running tests on the day's water samples.
Marv is a geochemist who studies the gases dissolved in the vent fluids. On this trip, he has also been trying to isolate bacteria that make their living from those gases. He's at the University of Washington, Seattle.
Also from the University of Washington, Eric takes the day's water samples and runs them through an astonishing machine that captures the gas for study back in Seattle. He's known as "Exxon" for the odors his machinery releases at the end of a run.
A former student of Marv's, Betsy just took a job at Rutgers. On this cruise, she has been studying bacteria that produce energy from hydrogen, as opposed to photosynthesizing from the sun or chemosynthesizing from sulfur.
10-18-1999, 09:43 PM
More on Gold'd wild idea:
Pioneering physicist Thomas Gold explores the likelihood of a subterranean biosphere, one that exists in a gaseous atmosphere at a very high temperature and pressure, and survives on chemical energy--hydrocarbons. This stunning book offers new insights into the origins of life, the origins of natural gas and petroleum, and the distribution of life in the universe.
Deep within the earth's crust there exists a second biosphere, composed of very primitive heat-loving bacteria and containing perhaps more living matter than is present on the earth's entire surface. That is the astounding premise of this new book by Thomas Gold…more at http://www.amazon.com/exec/obidos/ts/book-reviews/0387985468/qid=940300665/002-5416095-3141855
10-19-1999, 01:17 PM
I like to make a clear distinction between biospheres thriving around oceanic geothermal vents, and the much-more-recently-discovered subterranean bacteria.
Although both the underwater-volcano life and the deep-underground life ultimately derive their energy from geothermal heat, they are VERY different biospheres.
Quick-N-Dirty Aviation: Trading altitude for airspeed since 1992.
10-19-1999, 07:52 PM
What biochemical distinction do the 2 classes of bacteria have?
10-21-1999, 02:28 PM
Okay, the theory to which you refer is often called the autotroph hypothesis. Its supporters use evidence of chemoautotrophic bacteria (they make their food from chemical reactions such as the H2S one rather than from sunlight.) in today's oceans to suggest that means of producing organic compounds for food is present in simple compounds.
The other is the heterotroph hypothesis. Supporters of this theory argue that the processes needed by an organism to create food are too complicated to have been in the first organisms. They contend that the first ones ate food. The problem is: what did they eat without an organism producing food? Stanley Miller's synthesis of amino acids in an environment similar to the supposed composition of the early atmosphere (debated today) suggests that organic compounds may have been a food source without organisms to create them.
Still another theory is the meteorite theory (self explanatory), but even if this is the case, how did that life originate?
10-21-1999, 02:29 PM
I apologize for using the word theory loosely. They are all technically hypotheses.
10-21-1999, 07:35 PM
They use a lot of words to describe the early/primitive life, but since I've read the free stuff and not the actual papers, I'm not sure what the actual chemistry is with these bacteria.
10-22-1999, 07:35 PM
I'm not sure what the chemistry of the deep subterranean critters is, either. I just remember biology types saying, "Gosh, these things are really really wierd."
BTW, one currently favored theory is that the first living organisms weren't protein-based (or amino-acid-based) at all; they were little strands of RNA with enough molecular machinery to make crude copies of themselves. This is called the "RNA World Hypothesis". There's purportedly a good deal of supporting evidence for it, but I haven't the slightest clue what this evidence consists of.
Quick-N-Dirty Aviation: Trading altitude for airspeed since 1992.
10-22-1999, 10:32 PM
Sort of like a virus, then?
10-23-1999, 02:11 PM
I have some information supporting the RNA hypothesis. Thomas Cech won the Nobel Prize in Chemistry for discovering ribozymes in the Tetrahymena species. Ribozymes are RNA-based enzymes. Before he had done this, the common belief was that all enzymes were protein-based.
10-24-1999, 10:01 PM
In some sense, the biochemistry you can come up with using C, H, N and O as the main elements, is somewhat predetermined. It's hard to imagine that amino acids would not arise out of common chemistry. The rest requires more speculation. I find it difficult to believe that the ribose of RNA came before peptides.
10-25-1999, 04:06 PM
It is now in debate whether amino acids came first since the early atmosphere of the Earth is currently debated. Other people have tried experiments similar to Miller's with different chemical conditions in the atmosphere and have created different organic compounds, such as sugars and lipids.
10-27-1999, 08:54 PM
I find it difficult to believe that the ribose of RNA came before peptides.
Ribose is also found in Adenosine Triphosphate (ATP), which is one of the principal sources of energy for nonspontaneous reactions in living organisms. Since it is so important to organisms, I would expect that it existed at least around the same time as peptides.
Search for information on proteinoid microspheres to check and see if they function with ATP.
10-30-1999, 04:35 PM
I guess I missed the question in the OP. I think the big picture here IS what is the ULTIMATE source of energy in this (hydrothermal vent)system. I'm not that familiar with the biochemistry of chemosynthesis, but I'm willing to bet that the chemosynthetic bacteria are still generating ATP as an end product. Are we talking biochem here? ATP being the "coin of the realm/the gallon of gas" to pay for unfavorable chemical reactions, is it so suprising that there are different ways of generating it? Without sunlight, I mean. Non-photosynthetic ecosystems--pretty cool, I think. What's out there on the moons of Jupiter and Saturn (if anything)? Sunlight and plants don't seem to be a must.
10-31-1999, 02:55 PM
Even if the bacteria are generating ATP as an end product, via some type of anaeriobic respiration, it does not answer the question whether these were the first living things.
The problem with trying to answer this question is that all the current hypotheses have their own strengths and weaknesses. For instance, is chemosynthesis really that easy a process that chemoautotrophic organisms came before heterotrophs? I'm not sure about the biochemistry of it, myself.
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