Recent scientific investigations indicate that during the Archean Eon, approximately 3.4 billion years ago, primordial microorganisms harnessed molybdenum, a trace metal during that epoch, and even explored the utilization of tungsten. These revelations have the potential to reshape the methodologies employed by astrobiologists in their quest for extraterrestrial life.
Geochemical data points towards an exceedingly limited presence of molybdenum in Earth’s ancient, oxygen-deficient oceans, despite its near-universal necessity for contemporary life.
Previous scientific hypotheses posited that life might have initially employed tungsten before adapting to utilize molybdenum once its availability increased.
Professor Betül Kaçar from the University of Wisconsin-Madison, along with her research team, embarked on a mission to validate this supposition.
“The evolutionary trajectory of the transition metal molybdenum within biology, concerning its environmental context, presents an intriguing puzzle,” stated the researchers.
“Molybdenum is integral to fundamental biogeochemical transformations involving carbon, nitrogen, and sulfur, and prior studies have suggested that numerous metabolic pathways reliant on it possess deep historical roots.”
Within the scope of their investigation, the authors meticulously analyzed genomic repositories to pinpoint extant species possessing the genetic machinery for molybdenum assimilation, storage, and enzymatic functions.
Employing a computational method known as phylogenetic reconciliation, they meticulously reconstructed the evolutionary lineage of proteins that utilize molybdenum and tungsten throughout the entirety of the modern biosphere.
Furthermore, their study elucidated the cellular mechanisms governing molybdenum’s movement and utilization within living organisms, examining its intracellular transport from initial uptake through to catalytic processes.
Concurrently, the historical record of biological engagement with tungsten for transport and catalytic roles was also scrutinized.
Compiling existing data on the historical abundance of molybdenum, the team ascertained that, even in its scarcity, ancient terrestrial microbes managed to leverage this element, with evidence dating back as far as 3.3 to 3.7 billion years ago.
“It’s somewhat counterintuitive because the geochemical record suggests that molybdenum was far less abundant on early Earth billions of years ago, particularly before the emergence of oxygen-producing photosynthesis,” commented Aya Klos, a doctoral candidate at the University of Wisconsin-Madison.
“Yet, for reasons yet to be fully understood, life persisted in its evolution by employing biochemical processes that depend on molybdenum, despite its restricted accessibility.”
“These foundational biochemical strategies have been transmitted to the organisms we observe today.”
“Comprehending the elemental dependencies of primordial life can furnish astrobiologists with enhanced tools for identifying exoplanets that might sustain biological activity,” explained Professor Kaçar.
“This research underscores that the limited availability of an element does not preclude life from discovering its utility and even building complex systems around it.”
“Biological systems exhibit remarkable adaptability and ingenuity. Discoveries of this nature persistently remind us that the search for life beyond our planet necessitates an openness to contemplating unforeseen possibilities.”
A scholarly article detailing these findings has been formally published in the esteemed journal Nature Communications.
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A.S. Klos et al. 2026. Biological use of molybdenum and tungsten stems back to 3.4 billion years ago. Nat Commun 17, 3943; doi: 10.1038/s41467-026-72133-0
