Posted on 11/04/2005 5:00:06 AM PST by PatrickHenry
Minerals help molecules thought to have been essential for early life to form.
A team of US scientists may have found the 'primordial womb' in which the first life on Earth was incubated.
Lynda Williams and colleagues at Arizona State University in Tempe have discovered that certain types of clay mineral convert simple carbon-based molecules to complex ones in conditions mimicking those of hot, wet hydrothermal vents (mini-volcanoes on the sea bed). Such complex molecules would have been essential components of the first cell-like systems on Earth.
Having helped such delicate molecules to form, the clays can also protect them from getting broken down in the piping hot water issuing from the vents, the researchers report in the journal Geology [Williams L. B., et al. Geology, 33. 913 - 916 (2005).].
"It's very interesting that the clays preserve them," says James Ferris, a specialist on the chemical origins of life at Rensselaer Polytechnic Institute in Troy, New York. "It shows that this could be an environment where complex organic molecules can be formed."
Some like it hot
Hydrothermal vents are created when seawater that has seeped through cracks in the seafloor is heated by magma just below the surface. The water streams back out of the rock in a plume that can reach temperatures of around 400 °C.
Vents are a favourite candidate for the site where life first appeared. Their heat provides an energy source; the minerals provide nutrients; and the deep-sea setting would have protected primitive organisms from the destructive meteorite impacts that scoured the planet's surface early in its history.
But researchers have long wondered how, if early life did form in this environment, it escaped being boiled and fried by the harsh conditions.
The Arizona State team has shown that clay minerals commonly found at vents can encase organic molecules, keeping them intact.
Between the sheets
The group simulated the vent environment in the laboratory, immersing various types of clay in pressurized water at 300 °C for several weeks and looking at the fate of a simple organic compound, methanol, in this stew. They chose methanol because their earlier work had shown that the compound could be formed in a vent environment from simple gases such as carbon dioxide and hydrogen.
Clays generally consist of sheets made of aluminium, silicon and oxygen atoms, which are stacked on top of one another. In some of these materials, such as the clays saponite and montmorillonite, there is room for other atoms and molecules to slip between the layers.
Spouting soup
The researchers found that the methanol in their artificial vent system was converted to various large organic molecules over six weeks or so, so long as the clay's layers were spaced widely enough to hold the compounds.
"The clay provides a safe haven for the organic molecules, essentially like a 'primordial womb'," the team reports. Eventually, changes in the clay's mineral structure caused by heat, pressure and time may cause the sheets to close up and expel the molecules inside. But they think that some of these could spout out from the clay into less hostile environments than the hottest part of the vent, creating an organic soup in which life might arise.
These findings add weight to the idea that clays were the key to the origin of life. Previous research has shown that clays act as catalysts for the formation of polymer molecules such as the precursors of proteins and DNA. They can also encourage lipid molecules to arrange themselves into cell-like compartments called vesicles.
"I'd like to see the steps that one takes to get..."
Howdy there Elsie;
I'd say they have very, very vivid imaginations.
It takes a lot more than a vivid imagination to be a scientist. You actually have to back your assertions with logic and evidence.
XenuDidit placemark
"It takes a lot more than a vivid imagination to be a scientist. You actually have to back your assertions with logic and evidence."
Howdy there Quark2005;
Ok lets take the example of the "Iceman"...a recent discovery right?
Last night I watched a show about him, and with all of our wonderful modern equipment we have to use today they still came up with at least 6 different therories...???
I'm using snipets from here:
http://www.mummytombs.com/mummylocator/featured/otzi.theories.htm
Italian and Austrian authorities were shocked to discover that, rather than being a modern-day mountain climber, the man had died about 3000 B.C. He quickly came to be known as the Iceman, one of the oldest and best preserved human mummies ever found.
"using CAT scanning and carbon dating, scientists were able to learn much about the man's health and lifestyle, from the tools he used to the foods he ate, giving us much greater insight into the life of our ancestors during the Stone Age."
***To me the researchers seemed surprised at the tools he had with him.***
Ötzi the Iceman's Equipment
a bow and arrows, with quiver
an axe (with copper head)
the wooden frame and cords of a backpack (pannier)
ibex bones
two birch-bark containers
knife with woven sheath
a belt pouch
tassel with stone bead
a medicine bag (with medicinal fungus)
other tools
A great deal of research has gone into the study of the Iceman, and not all of it has been expertly done or helpful.
Theory One: Ötzi Froze to Death Peacefully. At first, scientists believed that Ötzi was caught in a heavy snowfall, fell asleep, and froze to death. They concluded this because there were no signs of predator attacks (and because they did not find conclusive evidence of other wounds). They believed that the body must have been covered with snow almost immediately or else the body would have been preyed upon.
Theory Two: Ötzi Was Injured in a Fight or a Fall Before He Froze to Death. Early x-rays (done in Innsbruck) appeared to show broken ribs on his right side. This caused endless speculation about his death: Were these fractured ribs the result of a fight or a fall shortly before his death? Could this fight or fall have led to his death? Or did he receive the broken ribs after he died? Konrad Spindler wrote about this theory in quite dramatic fashion in The Man in the Ice and Human Mummies.
Theory One: Discarded. The first theory was put to rest in June 2001 when the Iceman was x-rayed by a different team of scientists (in Bolzano). They discovered that he had an arrowhead buried in his left shoulder. In June 2002, they also discovered that the Iceman had a fairly debilitating wound to one hand.
Theory Two: Re-examined. The second theory suffered a set back, though when the new x-rays did not show any sign of broken ribs (though it is possible that the broken ribs did not show up as sometimes happens). The Italian radiology team believes that the original x-rays merely show the results of (1) compression (snow and ice pressing against the Iceman's ribcage) and (2) a misreading of the original x-ray (two ribs are overlapping, which can give the appearance of a fracture when none is actually there). [You can read all up-to-date information about the Iceman's death on the Ötzi news page.]
Even if there are no broken ribs, the Iceman showed obvious signs of a fight of some kind. Here are three current theories:
Theory 3. Ötzi was shot accidentally. According to Brenda Fowler, Dr. Annaluisa Pedrotti (University of Trento) speculates that the Iceman may have been shot by a hunter who buried Ötzi immediately.
Theory 4. Ötzi was a victim of homicide. Again, according to Fowler, Dr. Markus Egg (Romano-Germanic Central Museum) offers this thought: Ötzi was a shepherd who was killed by another shepherd who wanted a larger flock of animals. Dr. Eduard Egarter Vigl proposes other possibilities: a returning shepherd, he arrived home as his village was being attacked, or he arrived home to find that "another man had taken his wife during his absence" (Smithsonian).
Theory 5. Ötzi was a victim of attempted robbery and devised an unsuccessful plan (the Lizard Tail Gambit) to ensnare his assailant. Petr Jandacek, a teacher from New Mexico, is a student of Otziology and has proposed his own theory, taking all major facets of the case into account. Here is the short version:
Jandacek suggests that the Iceman was the victim of attempted robbery. Someone wanted his copper axe. Ötzi fought him off, injuring his hand in a knife fight. As he retreated up the mountain, the robber shot him in the shoulder with an arrow and followed him.
At this point, Ötzi planned a strategy to save himself. Using something like the Lizard Tail Gambit (a chess strategy, in which a pawn or two is sacrificed to achieve a better position), the Iceman placed his belongings (his backpack, bow, and his highly desirable ax) on top of some rocks; he placed his quiver on the ground a few feet away. Ötzi took only his dagger and his container of hot coals. He covered himself in a snowdrift, using a peephole to watch for his attacker. He placed his left arm under his chin and his right arm straight at his side, his right hand grasping a dagger in self defense, in case the gambit failed.
The snowfall was heavy, however, and the attacker gave up. Ötzi waited, until perhaps he fell asleep and froze to death, protected from predators by the snowdrift he had used for cover.
Theory 6. Ötzi was a victim of a power play. According to Walter Leitner of the Institute for Ancient and Early History at the University of Innsbruck in Austria, Ötzi may well have been a shaman and a highly respected member of his group. In a power play, another group of individuals wanted to assume that power--what better way than killing the Iceman. Leitner believes Ötzi was a shaman because of the possessions he had with in, in particular the copper axe which was not a common object. Leitner also believes that the attackers kept at a distance during their attack, perhaps because they were afraid of the shaman and what he might do. When Ötzi was wounded he may have tried to descend the mountain but was overcome (Leitner believes that it makes sense for Ötzi to have tried to go down the mountain, once he was wounded, rather than up to a higher position). By killing him in the mountains, well out of sight, his attackers may have hoped that his death (or disappearance) was seen as an accident.
As you can see, there are still many questions that need to be addressed (and that may never be answered). Perhaps with more research, Ötzi will provide more information to scientists. However, no theory will ever be proven beyond a shadow of a doubt--and many of the theories easily overlap. Stay tuned for the next one.
***As you can see all the different ideas of what happened to the "Iceman" yet no one can really know because none of us where there to see what happened to him...it's just guesswork...what each researcher "thought" happened to him.
If the researchers read their Bibles they wouldn't have been surprised at him having a copper headed ax.
Gen 4:22 To Lamech’s other wife, Zillah, was born Tubal-cain. He was the first to work with metal, forging instruments of bronze and iron. Tubal-cain had a sister named Naamah.***
Now taking this to the next step...today they have the evidence (iceman's body & all the tools he carried with him)...modern up to date equipment(cat scans; x-rays) to test him, and they still came up with various ideas of what happened to him. Not surprising because no one was there to see for themselves.
My logic ask's me this..."how in the world anyone can believe in the theory of evolution from a few bits and pieces of bones found in various places, and man's guesswork...when they can't even agree on the "Iceman"?
To me it boils down to "faith & belief", and very vivid imaginations.
No, not really. You're referring to a case where there really is uncertainty as to what happened, and legitimate scientific debate. Using a case that actually is controversial to try to obfuscate theories that are solid and not really controversial is a fallacy of composition .
Nice site.
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