Was This Life’s First Meal?

sciencehabit shares a report from Science Magazine: Studies of the origin of life are replete with paradoxes. Take this doozy: Every known organism on Earth uses a suite of proteins — and the DNA that helps build it — to construct the building blocks of our cells. But those very building blocks are also needed to make DNA and proteins. The solution to this chicken-and-egg conundrum may lie at the site of hydrothermal vents, fissures in the sea floor that spew hot water and a wealth of other chemicals, researchers report today. Scientists say they have found that a trio of metal compounds abundant around the vents can cause hydrogen gas and carbon dioxide (CO2) to react to form a collection of energy-rich organic compounds critical to cell growth. And the high temperatures and pressures around the vents themselves may have jump-started life on Earth, the team argues. The new work is “thrilling,” says Thomas Carell, an origin of life chemist at Ludwig Maximilian University of Munich who was not affiliated with the new project. The organic molecules the study generated include formate, acetate, and pyruvate, which Carell calls “the most fundamental molecules of energy metabolism,” the process of converting nutrients into cell growth. The new results support a long-held idea about the origin of life known as “metabolism first hypothesis.” It posits that geochemical processes on early Earth created a stew of simple energy-rich compounds that drove the synthesis of complex molecules, which eventually provided the materials for Darwinian evolution and life. The findings appear in the journal Nature Ecology & Evolution.