'False' biosignatures may complicate search for ancient life on Earth, other planets | CU Boulder Today | University of Colorado Boulder
http://www.colorado.edu/...alse-biosignatures-may-complicate-search-ancient-life-earth-other-planets
Self-assembling carbon microstructures created in a lab by University of Colorado Boulder researchers could provide new clues –
and new cautions – in efforts to identify microbial life preserved in the fossil record, both on Earth and elsewhere in the solar system.
The geological search for ancient life frequently zeroes in on fossilized organic structures or biominerals that can serve as “biosignatures,”
that survive in the rock record over extremely long time scales. Mineral elements such as sulfur are often formed through biological activity.
Microbes can also produce a variety of telltale extracellular structures that resemble sheaths and stalks.
However, according to new findings published today in the journal Nature Communications, carbon-sulfur microstructures that would be recognized
today by some experts as biomaterials are capable of self-assembling under certain conditions, even without direct biological activity. These
“false” biosignatures could potentially be misinterpreted as signs of biological activity due to their strong resemblance to microbial structures.
“Surprisingly, we found that we could create all sorts of biogenic-like materials that have the right shape, structure and chemistry to match
natural materials we assume are produced biologically,” said Associate Professor Alexis Templeton of CU Boulder’s Department of Geological
Sciences and senior author of the new study.