Non Sequitur by Wiley Miller for March 18, 2011

After the breakup of Pangaea, Australia was connected to South America, while North America and South America were separated. The geological record shows that.

Marsupials were the dominant form of mammal on this combined land mass, although a few straggling monotremes held on (there and nowhere else). The fossil record shows that marsupials used to be found throughout what is now South America.

When Australia and South America split, and the land bridge between North America and South America formed, the canids and the felids and the other non-marsupial mammals that had arisen and thrived in North America spread southward; neither the native herbivorous nor carnivorous marsupials could compete with the Northern immigrants, and now the only marsupials which are left on the planet are those which were safely isolated on Australia (along with those wacky monotremes). The sole exception being the North American opossums, who found save haven by migrating north, and hanging on (by their tails) for dear life.

We’re not just talking about individual species; we’re talking about huge classes of animalia (marsupials being not quite as bizarre as monotremes, but compared to other mammalia they’re still quite freaky) that come in contact with other huge classes of animalia, and prevail (or not) contingent upon their “fitness” for survival.

The geological record does not prove the fossil record, nor does the fossil record prove the geological record. But that the two reinforce one another is telling.

What’s the alternative? God saying “I’m going to put the only monotremes in Australia, and all the marsupials, except these opossums. I’m gonna put these in North America, with the wolves and the bison and the coyotes, where the deer and the antelope play.” If not God, was it Noah? Were the opossums playing dead when he made landfall in Sydney, and he neglected to disembark them until he hit New Orleans?