Molybdenum and the Rise of Complex Life

April 1, 2008 / Written by: Daniella Scalice

Researchers from NASA’s Exobiology and Evolutionary Biology Program have found a potential link between the presence of the element molybdenum in the ancient oceans on Earth and the expansion of complex life. Using molybdenum in ancient rocks as a proxy for the oxidation state of the early oceans, Clint Scott and Tim Lyons of the University of California-Riverside, Andrey Bekker of the University of Manitoba, and Ariel Anbar of Arizona State University found a period in time when the oceans were relatively oxygen- and molybdenum-deprived, which they argue was a retardant to the development of complex life. Their results, published in last week’s Nature, confirm earlier predictions that the metal should have been scarce in ancient oceans because there was so little oxygen in the atmosphere in those times; their results also concur with the fossil record, which indicates that complex life first evolved 2.7 billion years ago, but didn’t dominate the planet until 0.7 billion years ago.