Genes as Time Machines( 3.5 Billion Year-Old Genes Resurrect...)

3.5 Billion Year-Old Genes Resurrected to Serve as Probes of Early Life on

Earth.

GAINESVILLE, Fla., and MENLO PARK, Calif., Feb. 6 /PRNewswire/ -- Scientists at the Foundation for Applied Molecular Evolution, University of Florida (both at Gainesville, FL) and DNA2.0 (Menlo Park, CA) today publish a study in the journal Nature where more than 20 ancient genes were resurrected from organisms that lived between 500 million to 3.5 billion years ago.

"By studying proteins encoded by these primordial genes, we are able to infer information about the environmental conditions of the early Earth" said Dr. Eric Gaucher at the Foundation for Applied Molecular Evolution and lead scientist of the study. "Genes evolve to adapt to the environmental conditions in which an organism lives. Resurrecting these 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 researchers chose a gene that encodes a protein which captures the environmental temperature of the gene's host organism. In essence, the resurrected genes are ancient thermometers. These 'thermometers' were used to provide evidence that the oldest bacterial life forms lived at a hot temperature of 75 degrees C (~165 degrees F) 3.5 billion years ago, and slowly cooled to a temperature of 40 degrees C (~100 degrees F) by 500 million years ago.

"Remarkably, our results are nearly identical to geologic studies that estimate the temperature trend for the ancient ocean over the same time period. The convergence of results from biology and geology show that Earth's environment has continuously been changing since life began, and life has adapted appropriately to survive," said Dr. Gaucher.

"Although the concept of ancestral gene resurrection was proposed more than forty years ago, the development of efficient gene synthe
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