VIRGINIA KEY, FLA. (Nov. 17, 2006) The origin of life lies in unique ocean reefs, and scientists from the University of Miami's Rosenstiel School of Marine & Atmospheric Science have developed an approach to help investigate them better. A new article published in the November issue of Geology reveals how Dr. Miriam Andres' stromatolite investigation the first of its kind has begun to "fingerprint" ancient microbial pathways, increasing the understanding of how these reef-like structures form and offering a new way to explore the origins of these living records, which are considered to be the core of most living organisms.
Modern marine stromatolites are living examples of one of the earth's oldest and most persistent widespread ecosystems. Although rare today, these layered deposits of calcium carbonate are found in shallow marine seas throughout 3.4 billion-year-old geologic records. Ancient stromatolites represent a mineral record of carbonate chemistry and the evolution of early life. In the Geology paper, Dr. Andres and colleagues point out that incorrect assumptions have been made in interpreting stromatolite data: phototrophs, or oxygen-producers, were actually dominated by heterotrophs, or oxygen-consumers, in their contribution to stromatolite formation.
"The motivation for this study is that in ancient stromatolites, direct evidence of microbial activity is lacking," Dr. Andres explained. "Stable isotopes have provided a powerful tool to 'fingerprint' microbial pathways and better understand the sedimentary structures we see in the geologic record. Surprisingly, no study to date has documented this process for modern marine stromatolites."
Stromatolites are the oldest known macrofossils, dating back over three billion years. Dominating the fossil record for 80 percent of our planet's history, stromatolites formed massive reefs in this planet's primitive oceans. While stromatolites look much like coral reefs, they are act
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Contact: Ivy Kupec
ikupec@miami.edu
305-421-4704
University of Miami Rosenstiel School of Marine & Atmospheric Science
17-Nov-2006