GAINESVILLE, Fla. Using the genetic equivalent of an ancient thermometer, a team of scientists has determined that the Earth endured a massive cooling period between 500 million and 3.5 billion years ago.
Reporting today (Feb. 7) in the journal Nature, researchers from the University of Florida, the Foundation for Applied Molecular Evolution and the biotechnology company DNA2.0 describe how they reconstructed proteins from ancient bacteria to measure the Earths temperature over the ages.
By studying proteins encoded by these primordial genes, we are able to infer information about the environmental conditions of the early Earth, said Eric Gaucher, Ph.D., president of scientific research at the Foundation for Applied Molecular Evolution in Gainesville and the studys lead scientist. Genes evolve to adapt to the environmental conditions in which an organism lives. Resurrecting these since long-extinct genes gives us the opportunity to analyze and dissect the ancient surroundings that have been recorded in the gene sequence. The genes essentially behave as dynamic fossils.
The team wanted to measure Earths temperature billions of years ago to learn more about life on Earth during the Precambrian period. But instead of taking the traditional route analyzing rock formations or measuring isotopes in fossils they opted to do what they knew best: protein reconstruction.
Weve analyzed the temperature stability of proteins inside organisms that were around during those times, said Omjoy Ganesh, Ph.D., a structural biologist in the UF College of Medicines department of biochemistry and molecular biology. The ancient oceans were warmer. For ocean organisms living during that time to survive, the proteins within them had to be stable at high temperatures.
After scanning multiple databases, the scientists struck gold with a protein called elongation factor, which helps bacteria string together amino acids to form other protein
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University of Florida