So maybe God said...

..."Let there be plate tectonics?!"

Among my iGoogle science headlines this morning are dueling items on plate tectonics. Click the second of the paired links to read the full specific items, click the "from" links to more generally peruse the source sites...

From LiveScience.com...
Scientists: Earth Barely Supports Life
(By Jeanna Bryner, LiveScience Staff Writer)

AUSTIN, Texas—If Earth had been slightly smaller and less massive, life might never have gained a foothold.

The key to life on Earth as we know it, scientists figure, is plate tectonics—the forces that move continents and build mountains. And the more massive a world is, the thinner its plates are. Thinner plates are weaker and more easily moved and so able to support the kinds of crucial planet-shaping plate tectonics experienced on this planet over the billions of years that life evolved from simple one-celled organisms to complex creatures that can fly, swim and read.

"Plate tectonics are essential to life as we know it," said Diana Valencia of Harvard University, who presented research on the topic here Wednesday at a meeting of the American Astronomical Society. "Our calculations show that bigger is better when it comes to the habitability of rocky planets."

The study reveals Earth has been on the edge of habitability from the beginning, and just eked by to allow life-friendly conditions.

The results give hope to astronomers looking for life on other planets.

. . . .

And from ScientificBlogging.com...
Theoretical Model: Plate Tectonics May Be On-Again, Off-Again Process

The motion, formation, and recycling of Earth’s crust—commonly known as plate tectonics—have long been thought to be continuous processes but new research by geophysicists suggests that plate tectonic motions have occasionally stopped in Earth’s geologic history, and may do so again.

The findings could reshape our understanding of the history and evolution of the Earth’s crust and continents.

Synthesizing a wide range of observations and constructing a new theoretical model, researchers Paul Silver of the Carnegie Institution of Washington and Mark Behn of the Woods Hole Oceanographic Institution (WHOI) have found evidence that the process of subduction has effectively stopped at least once in Earth’s past.

. . .

Though such a shutdown defies the prevailing wisdom about plate tectonics, Silver and Behn read the geologic evidence to suggest that just such a dramatic decrease in subduction happened about one billion years ago, after the formation of the supercontinent Rodinia.

Their findings—captured in a paper entitled "Intermittent Plate Tectonics"—were published in the January 4 issue of the journal Science.

. . . .