Origin of Life: Cold RNA world (Introduction)

by David Turell , Monday, December 23, 2013, 16:04 (3989 days ago) @ David Turell

"The RNA enzyme's effectiveness at cold temperatures suggests ice was crucial to the first life. When a mix of RNA and metal ions freezes, growing ice crystals suck up the water, leaving tiny pockets of RNA and concentrated salt. RNA replication can happen in these pockets. "They're a little bit like artificial cells," says Holliger, and could be where evolution started.-"It certainly makes a cold RNA world something to think about," says RNA expert Adrian Ferré-D'Amaré of the National Heart, Lung and Blood Institute in Bethesda, Maryland.-"However, the theory has some weaknesses. At cold temperatures, RNA strands often stick together, making it tricky to separate them after the RNA has been copied. Primitive life would need to warm up to separate the strands, says Jack Szostak of Harvard Medical School. "It couldn't just live at continuously cold temperatures."-True, says Holliger, but there's a fix. "Ice freezes and melts all the time, so you can easily see how an RNA replicator could be enclosed and then released in a cyclical way and allowed to spread."-Szostak also points out that the enzyme only occasionally makes long strands of RNA. "I'm afraid we still have a long way to go to get a self-replicating ribozyme."-http://www.newscientist.com/article/mg22029413.600-earths-first-life-may-have-sprung-up-in-ice.html-Yes they do.