Geoscience Reference
In-Depth Information
For Doug and Dan, at least, this solved the problem of survival. Of course you could poke one
thousand small holes into the Snowball ocean. You could probably make tens of thousands without
compromising the model, and many of them could be much bigger than a dinner plate. With this many
refuges, says Doug, every species that needed to make it through the Snowball could do so easily.
There's no need for a Slushball. Life could survive an all-out, full-on Snowball with no problem at
all.
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the Snowball theory has survived every challenge that's been thrown at it. And thanks to Paul
and his proselytizing, there has now been a radical transformation in scientific attitudes to the ice
rocks. In a few short years Paul has achieved the feat that eluded Brian Harland, Joe Kirschvink, and
anyone else who became intrigued by the Earth's Precambrian ice rocks. Virtually everyone now says
that this was a time of extraordinary ice, cold and catastrophe. Even critics like Nick Christie-Blick,
who still believe in the Slushball, admit that ice went almost all the way. Paul has taken an idea that
was once too shocking to be considered, and brought it into the scientific limelight.
He could have stopped there. But there's another part of the Snowball story that he'd dearly love to
be true. While Paul continues to strengthen his geological case, he's also fascinated by the biological
implications. Was the Snowball the creative spark for the new life that followed?
Paul has believed from the beginning that the ice and its aftermath somehow triggered life's
biggest evolutionary moment since it first appeared on Earth: the switch from simple to complex.
Without the Snowball, he thinks, there would have been no animals, no richly diverse Earth, and no
people to argue over it. Paul, though, is not a biologist. What do the experts say?
