[VadeRetro]

But in Precambrian times (which lasted up until 544 million years ago), marine organisms in the open ocean did not produce carbonate skeletons -- and ancient rocks from the end of the Precambrian geological age indicate that huge glaciers deposited layers of crushed rock debris thousands of meters thick near the equator. If the land was frozen near the equator, then most of the surface of the planet was likely covered in ice, making Earth look like a giant snowball, the researchers said.

A nice Scientific American article on the Snowball Earth hypothesis, which has gained considerable acceptance. (But some people think it was really only a "Slushball Earth.")

[Physicist]

I favor Gelati Earth myself. Mmmm...lemon.

[PatrickHenry]

PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]

[gore3000]

A nice Scientific American article on the Snowball Earth hypothesis

Scientific American is really going off the deep end. In a world covered with ice there could never have been the numerous marine life we know existed long before the Cambrian.

[Doctor Stochastic]

Snowcone Earth?