A rare metal may have been central to life much earlier than expected
NASA-funded researchers say life on Earth was using molybdenum more than 3 billion years ago, a finding that pushes an important biochemical capability deep into the planet’s early history. The study, published in Nature Communications, is described as the first to show that molybdenum supported ancient life as far back as 3.3 to 3.7 billion years ago, well before the metal became abundant in Earth’s oceans.
The result matters because molybdenum sits inside enzymes that speed up some of biology’s most consequential reactions, including parts of the carbon, nitrogen, and sulfur cycles. Without that catalytic help, those reactions can still occur, but too slowly to sustain life as it is known today. In that sense, asking when life started using molybdenum is also a way of asking when certain powerful metabolic strategies became available.
The paradox of a scarce but essential element
On modern Earth, molybdenum is comparatively accessible. But billions of years ago, geological evidence suggests that only trace amounts were present in the oceans. Levels rose much later, around the broad period when photosynthetic microorganisms helped drive the Great Oxidation Event roughly 2.45 billion years ago. That long gap created an open question for astrobiologists: if molybdenum was so scarce on ancient Earth, did early life rely on other metals instead?
Tungsten has often featured in that discussion because it can behave similarly in cells and is still used by some organisms that live in extreme environments. The new work suggests that, even under scarcity, molybdenum entered life’s toolkit far earlier than many researchers might have expected.







