Was life on Earth born in a clay womb?

[muriel_volestrangler]

Primordial clay "wombs" that lie scattered around ocean floors played a crucial role in fostering early life on Earth, according to a team of scientists. The clay structures were found in deep waters, in and around ocean floor volcanic vents called black smokers, so named because they churn out hot black particles from the Earth's crust.

By providing a haven for molecules brought up from the Earth's interior, the wombs protected them from the harsh environment until they formed the most basic building blocks of life, the scientists say. Black smokers form along the edges of mid-ocean ridges. The rich variety of chemicals they emit supports a unique ecosystem including bizarre bacteria and unique species of worms. Scientists believe that these hot, sulphur-rich waters may have been ideal for life to evolve.

Until now researchers have been puzzled as to how molecules could have survived the 300C (572F) temperatures in volcanic vents, but Lynda Williams and her team at Arizona State University, found that lumps of clay that build up on the inside walls of the vents could have captured, then protected, key molecules for around six months. The clay deposits eventually break away and spill out onto the ocean floor, where they break open, releasing the molecules into cool surrounding waters.

Dr Williams's group recreated the high temperature and pressure environment of a black smoker in the laboratory to examine whether organic molecules, the building blocks of life, could grow on various types of clay surface. "We simulated the reactants that we know can exist in black smoker environments, to see what organic compounds would form in nature," she said. Six weeks into the experiment they discovered that one type of clay mineral, known as smectite, helped organic molecules to survive.

http://www.guardian.co.uk/uk_news/story/0,3604,1606475,00.html

[NNadir]

1. This could have bearing on one of the fundamental questions about life.

The origin of asymmetry. This is still a great mystery.

If my memory serves me well, certain types of quartz crystallize in an asymmetric fashion.

[Celebration]

2. asymmetry?

Was there symmetry first, and assymmetry later? Symmetry seems as mystifying to me as assymmetry....actually a whole lot is a mystery to me. Certainly the idea of my "ancestors" being in clay wombs in the bottom of the ocean is mind boggling.

What is mystifying to me is all the spirals in life forms, eg., seashells that use golden mean, etc.



http://www.mathacademy.com/pr/prime/articles/fibonac/

So it seems it is some sort of rule or plan. Why? When and where did it start? I am probably just unenlightened and someone here should be able to answer this.

[phantom power]

3. I expect patterns like that are a consequence of...

the fact that certain ratios are a natural consequence of the way that organisms grow via cell division. For one instance, cells dividing according to certain patterns can easily follow the fibonacci sequence in their population.

The relation between this kind of growth and macroscopic patterns isn't obvious to me, and I've never seen any hard proof, but guys like PZ Meyers over at his Pharyngula site might know. He's into the biology of embryology and organism growth.

[htuttle]

6. Inorganic crystals are naturally symmetric

...because the crystal is sort of a reflection of the actual bonds between the molecules or atoms. For example: if you build something out of rectangular Legos, it's going to have 90 degree corners, no matter what you do with them. I think that spirals in sea shells occur because one part of the shell gets created slightly faster than the other, leading to an outward spiral.

Speaking of plans and designs: when two things (or several million things) all evolve and change together, they are going to become adapted to each other. This, on later examination, looks like it was 'planned' that way. For example, if you rub a 2x4 against the corner of a brick, sooner or later, you will see a notch in the 2x4. If someone just finds them later, they might think that the wood was 'designed' to fit the corner of the brick, since it fits precisely into the groove. It was not, of course -- the brick made the groove.

[NNadir]

7. Quartz crystals are not all symmetric.

In fact the rotation of plane polarized light that at one time defined chirality was discovered in quartz crystals by Biot, just three years after the discovery of polarized light itself by Malus.

See Eliel and Wilen The Stereochemistry of Organic Compounds Wiley 1994 pg 2-3.

In the case of quartz crystals, the chirality does not derive from the molecular structure, which is tetrahedral with each silicon bonded to four oxygens, but from the crystal structure and the connectivity of the tetrahedra with one another.

On a planetary scale, quartz is racemic, but individual enantiomeric crystals exist, much as tartaric acid crystals can form from a solution of racemate, famously shown by the painstaking historical work of Pasteur.

[phantom power]

4. Are you referring to preference in chirality?

[NNadir]

5. Yes, this is to what I am referring.

The origin of biological asymmetry, which is a subset of chirality, is a mystery.

Many possible origins have been supposed, including an influence of beta decay, which is asymmetric. But the problem is not even close to being explained.

[On the Road]

8. I've Been Skeptical of the "Tidal Pool" Story

To generate life, you need very long-term stability. Some scientists have speculated that life began deep underground. The "clay womb" hypothesis is better.

[Odin2005]

9. A lot of the data seems contradictory...

The deep seas would of been the safest place for life to start, and the basal position of Hyperthermophilic Bacteria and Archaea (aka Archaebacteria) on ribosomal RNA trees puts them at the base. But newer data puts the the gram-positives at the base of the Bacteria and that thermophilly evolved amny time independently, with Hyperthermophily being a specialty of the Archaea (the hyperthermophilic Bateria got thier abilities from lateral gene transfer with Archaea). Also, I read in an intresting book on oxygen biochemistry called Oxygen: The Molecule that Changed the World that the enzymes that protect against damagge caused by free radical molecules produced by using oxygen may have originally evolved to protect against free radicals made by UV light hitting water molecules, and since these protective enzymes are found in organisms in all 3 domains (Bacteria, Archaea, Eucarya), that the last common ancestor of all life lived in the surface wathers of the ocean, the exact worst place for life to start because of the UV light and the big asteroids coming in and boiling away the top few hundred feet of the ocean. :crazy: