ANATOMY

Detailed explanation-1: -Life on earth probably began in the depths of the ocean and not on the planet’s surface, claim scientists. The research is reported in the latest edition of the Royal Society of Chemistry journal Chemical Society Reviews.

Detailed explanation-2: -The atmosphere was mostly nitrogen, carbon dioxide and no oxygen. There was also no life. Yet deep down at the bottom of the ocean, something was beginning to happen. Hot chemicals rising through the sea floor enabled a chemical reaction between hydrogen and carbon dioxide, producing simple organic compounds.

Detailed explanation-3: -Life is believed to have originated in sea water (also known as earth’s primordial soup) because sea water contained all the essential elements that were required for the origin of first life. Secondly, at the time of origin of life, the ozone layer was not formed, so terrestrial origin of life was not feasible.

Detailed explanation-4: -Evidence shows that life probably began in the ocean at least 3.5 billion years ago. Photosynthesis began more than 2.5 billion years ago-the Great Oxidation Event. But it took hundreds of millions of years for enough oxygen to build up in the atmosphere and ocean to support complex life.

Detailed explanation-5: -First cells likely arose in steamy mud pots, study suggests. Earth’s first cellular life probably arose in vats of warm, slimy mud fed by volcanically heated steam-and not in primordial oceans, scientists say. (Also see “All Species Evolved From Single Cell, Study Finds.")