How Did Earth’s Primitive Chemistry Get Kick Started?
By NASA // May 19, 2014
Answers may lie under the sea
ABOVE VIDEO: Life on Earth began in the seas. For millions of years the Earth”s surface was scorched by harmful ultraviolet rays from sun and there was almost no life on land. Simple plants and Algae grew at the edges of the sea.NASA – Three papers co-authored by Mike Russell, a research scientist at NASA’s Jet Propulsion Laboratory strengthen the case that Earth’s first life began at alkaline hydrothermal vents at the bottom of oceans.
How did life on Earth get started? Scientists are interested in understanding early life on Earth because if we ever hope to find life on other worlds, especially icy worlds with subsurface oceans such as Jupiter’s moon Europa and Saturn’s Enceladus, we need to know what chemical signatures to look for. Two papers were published in the journal Philosophical Transactions of the Royal Society B provide more detail on the chemical and precursor metabolic reactions that have to take place to pave the pathway for life. Russell and his co-authors describe how the interactions between the earliest oceans and alkaline hydrothermal fluids likely produced acetate (comparable to vinegar). The acetate is a product of methane and hydrogen from the alkaline hydrothermal vents and carbon dioxide dissolved in the surrounding ocean. Once this early chemical pathway was forged, acetate could become the basis of other biological molecules. They also describe how two kinds of “nano-engines” that create organic carbon and polymers, energy currency of the first cells, could have been assembled from inorganic minerals.
A paper published in the journal Biochimica et Biophysica Acta analyzes the structural similarity between the most ancient enzymes of life and minerals precipitated at these alkaline vents, an indication that the first life didn’t have to invent its first catalysts and engines. “Our work on alkaline hot springs on the ocean floor makes what we believe is the most plausible case for the origin of the life’s building blocks and its energy supply,” Russell said.
“Our work on alkaline hot springs on the ocean floor makes what we believe is the most plausible case for the origin of the life’s building blocks and its energy supply,” Russell said.