PREHISTORIC BACTERIUM WAKES FROM 250-MILLION-YEAR SLEEP WebPosted Wed Oct 18 18:33:38 2000 LONDON--Scientists have revived what they believe is the oldest living creature ever found – a bacterium that's lived in a state of suspended animation for the past 250 million years. The bacterium was found in a tiny, fluid-filled air bubble inside a salt crystal, about 560 metres underground at a site east of Carlsbad, New Mexico. Scientists in Pennsylvania and Texas determined the age of the bacterium through fossil and radiation tests of the rock sample it was found in. They are confident the germ was locked away since the salt crystal's formation 250 million years ago. If it is as old as they say, the germ would give science a peek into a fascinating period in our planet's evolution. The bacterium would have been alive during the Paleozoic Era, when the Earth experienced its largest mass extinction in history. At the end of the Paleozoic Era, about 245 million year ago, approximately 90 per cent of all marine life was wiped out for reasons that are still unknown. Russell Vreeland, from West Chester University in Pennsylvania, and one of the authors of the study, says the genetic makeup of the bacterium could also help biologists map the evolutionary journey of the organism and its present-day relatives. DNA tests show the prehistoric bacterium is related to Bacillus , bacteria found in soil, water and dust. However, there is the possibility that the bacterium could have seeped through the salt in small drops of water because, unlike rocks or permafrost, salt is not an impermeable substance. Scientists have reported finding organisms up to 650 million years old in salt since the 1960s, but the findings were met with skepticism because of contamination fears. The scientists took pains to prevent contamination with the new bacterium. The testing was performed inside a contamination laboratory on the Pennsylvania campus. The findings appear in this week's issue of Nature . Copyright © 2000 CBC All Rights Reserved |