Diamonds May Have Jumpstarted Life on Earth
LiveScience Managing Editor, www.LiveScience.com
One of the greatest mysteries in science is how life began. Now one group of researchers says diamonds may have been life's best friend.
Scientists have long theorized that life on Earth got going in a primordial soup of precursor chemicals. But nobody knows how these simple amino acids, known to be the building blocks of life, were assembled into complex polymers needed as a platform for genesis.
Diamonds are crystallized forms of carbon that predate the oldest known life on the planet. In lab experiments aimed to confirm work done more than three decades ago, researchers found that when treated with hydrogen, natural diamonds formed crystalline layers of water on the surface.
Water is essential for life as we know it. Also, the tests found electrical conductivity that could have been key to forcing chemical reactions needed to generate the first birth.
When primitive molecules landed on the surface of these hydrogenated diamonds in the atmosphere of early Earth, a few billion years ago, the resulting reaction may have been sufficient enough to generate more complex organic molecules that eventually gave rise to life, the researchers say.
The research, by German scientists Andrei Sommer, Dan Zhu, and Hans-Joerg Fecht at the University of Ulm, is detailed in the Aug. 6 issue of the American Chemical Society's journal Crystal Growth & Design. Funding was provided by the Landesstiftung Baden-Wurttemberg Bionics Network.
Another theory, called panspermia, holds that life on Earth arrived from space, as organisms rained down inside tiny meteors or giant comets.
The new research does not conclusively determine how life began, but it lends support to one possible way.
"Hydrogenated diamond advances to the best of all possible origin-of-life platforms," the researchers contend.
How Are Diamonds Made?
Diamonds are made out of carbonhighly organized carbon, that is. Geologists are still guessing how diamonds formed in the Earth from 1 billion to 3 billion years ago, according to a recent study in the journal Nature, but they think the recipe follows something like this:
1. Bury carbon dioxide 100 miles into Earth.
2. Heat to about 2,200 degrees Fahrenheit.
3. Squeeze under pressure of 725,000 pounds per square inch.
4. Quickly rush towards Earths surface to cool.
If the process sounds a little difficult, thank a synthetic diamond manufacturer: There are now two ways to make diamonds in the laboratory.
The first synthetic method is called high pressure, high temperature (HPHT for short). Its the closest thing to the diamond-producing bowels of the Earth, subjecting graphite (yes, the stuff in a No. 2 pencil, which is made from pure carbon) to intense pressure and heat. Tiny anvils in an HPHT machine squeeze down on the graphite as intense electricity zaps it, producing a gem-quality diamond in just a few days. These diamonds, however, arent as pure as natural diamonds because a metallic solution is mixed in with the graphite.
The other diamond-producing methodcalled chemical vapor depositionturns its back on intense pressure but cranks out diamonds more flawless than nature can produce. Manufacturers place a piece of diamond into a depressurizing chamber, then zap natural gas with a microwave beam. As the gas is heated to almost 2,000 degrees, carbon atoms rain down onto the diamond in the chamber and stick to it, growing a perfect sheet of diamond overnight.
While De Beers isnt happy with its new competitors, computer manufacturers have something to be excited about: At temperatures that would melt silicon wafers, sheets of synthetic diamond stay rock-hard.