Saturday, February 18, 2012

Life's first cells probably arose from thermal pools

One of the biggest questions of the evolution of life, is how its most basic form came to be. Cells, spheres covered by a lipid layer containing DNA, proteins and various cellular machines which all work together to function as a single organism. It is hard to imagine how the first cells could have been created from a 'soup' of inorganic molecules. Scientists believe it all started about 4 billion years ago. At the University of Osnabrück, scientists argue that the first cells probably arose from thermal pools: extremely hot sources of water and various elements, that are similar to the conditions found inside cells.

Birth place
Scientists think the first cells must have been created in places that are similar in conditions to the stuff we find inside cells. For example, there is 75 times more potassium than sodium in cells, which means they probably did not arise from the salty sodium-rich seas. Combining this with information about other cellular characteristics, the scientists noted that thermal pools match the conditions that would allow for the creation of cells as we know them.

The first cells were probably very leaky, as opposed to the structures we find today. Molecules and ions could flow relatively freely in and out of the cell, while today's cells have specialized transport structures to allow the flow. It would allow primordial cells to more effectively acquire the necessary components for life. Other elements that make up a cell are thought to be derived from rocks that are rich in minerals.

It is hard to recreate the conditions that would allow for cells to be made. The findings published by the University of Osnabrück do not offer much proof, but their arguments do provide some insight into how creation of cells might have happened. We need to find a way construct a reasonable 'soup' with just the right conditions to allow cell formation, because it is one of the most important steps in the creation of life. Nevertheless, it is nearly impossible to recreate the actual conditions of thermal pools 4 billion years ago. Also, it is known that cells have changed their composition during the course of evolution, which means it will remain nothing but a theory, albeit an interesting one.

The arguments brought forward by the German scientists help us to construct the conditions in which life might have started. Recently, several studies have been published about how life as we know it came to be. A group of scientists lead by Rutgers University traced back the evolution of photosynthesis; the creation of energy from sunlight. Also recently published was a lab experiment that showed formation of organisms consisting of more than one cell is not all that hard to achieve.

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