Scientists all over the world (Image Courtesy: Discover.com) are trying to unravel the mysteries of life, and where it came from. One particularly interesting branch of this endeavor is to create life, from scratch, in a laboratory setup. Jack Szostak at Harvard Medical School is one of such scientists. He and his team demonstrate that creation of such a life (a cell) might be astonishingly simple.
Szostak started with chemicals/compounds that might have been available on primitive Earth. For example, certain nucleic/fatty/amino acids are created when a reducing atmosphere (atmosphere lacking oxygen), containing a lot of methane, water, ammonia and carbon-dioxide is subjected to ultraviolet light (ancient earth had no ozone layer), and electric discharge. Fatty acids have the tendency to form bubbles (our cell membranes are composed of phospholipids, which are fatty acids). Invariably, some of these bubbles trap nucleic acids. These bubbbles also have the interesting property that these allow small molecules to enter/exit, but trap larger molecules. When the nucleic acids interact with each other inside the bubble, they make large chains (like our RNA/DNA), which are trapped by the bubble. Suddenly, we have a mini reaction chamber! The bubbles collide with each other, and larger bubbles spontaneously assimilate the smaller ones, just like small water droplets on a surface coalesce into larger droplets.
Now, we have a small evolutionary mechanism in play. Larger bubbles compete amongst each other for resources (nucleic acids), and the most successful ones win out. Some of these large bubbles might evolve a mechanism to split into smaller bubbles, just like a cell division in our body. Over time (millions of years), might it not be possible to have nucleic chains (like certain RNA molecules, that can reproduce without the help of other molecules) that can copy itself? This, plus some mutations, and voila, we have a Survival of the fittest struggle in motion, which might (just might!) eventually lead to single celled organisms, and eventually, us.
If only there were a way to peek back in time!