Arunas L Radzvilavicius, theoretical biologist at University College London writes the following:
For nearly nine decades, science’s favorite explanation for the origin of life has been the “primordial soup”. This is the idea that life began from a series of chemical reactions in a warm pond on Earth’s surface, triggered by an external energy source such as lightning strike or ultraviolet (UV) light. But recent research adds weight to an alternative idea, that life arose deep in the ocean within warm, rocky structures called hydrothermal vents.
A study published last month in Nature Microbiology suggests the last common ancestor of all living cells fed on hydrogen gas in a hot iron-rich environment, much like that within the vents. Advocates of the conventional theory have been sceptical that these findings should change our view of the origins of life. But the hydrothermal vent hypothesis, which is often described as exotic and controversial, explains how living cells evolved the ability to obtain energy, in a way that just wouldn’t have been possible in a primordial soup.
Under the conventional theory, life supposedly began when lightning or UV rays caused simple molecules to join together into more complex compounds. This culminated in the creation of information-storing molecules similar to our own DNA, housed within the protective bubbles of primitive cells. Laboratory experiments confirm that trace amounts of molecular building blocks that make up proteins and information-storing molecules can indeed be created under these conditions. For many, the primordial soup has become the most plausible environment for the origin of first living cells.
But life isn’t just about replicating information stored within DNA. All living things have to reproduce in order to survive, but replicating the DNA, assembling new proteins and building cells from scratch require tremendous amounts of energy. At the core of life are the mechanisms of obtaining energy from the environment, storing and continuously channelling it into cells’ key metabolic reactions….
Read the full article here
More:
- The physiology and habitat of the last universal common ancestor.
- NASA asteroid probe may find clues to origins of life on Earth.
Photo: Pacific Ring of Fire Expedition. Active “smoker” chimneys precipitating iron, copper and zinc sulfides from 230øC fluid. 9 meters tall from the base to the top of the chimneys seen in the photograph. Dark beehive-type chimneys, here about 30 cm tall, commonly sit on top of these structures. Mariana Arc region, Western Pacific Ocean. April, 2004.
Photo Credit: Pacific Ring of Fire 2004 Expedition. NOAA Office of Ocean Exploration; Dr. Bob Embley, NOAA PMEL, Chief Scientist. NOAA Photo Library/Flickr, CC BY-SA