There's more and more evidence is there's an earthly calamity that happens about every 14,000 years it pretty much wipes the surface of the Earth clean. The best area I've heard is the one presented by Jan Thomas and Adam and Eve which says that the crust of the Earth turns loose from the center of the earth like the peel of an orange slipping off the orange and it rotates until the equator becomes the poles and the poles become the equator. It explains why woolly mammoths in Russia or Frozen with food still in their mouths and they weren't even cold winter mammoths they were actually summer mammoths. And vegetation that exists in arctic areas Frozen for thousands of years can only grow in southern tropical areas so obviously the Arctic at one point was at the equator. Apparently has something to do with the Earth's magnetic field being changed as it goes through a certain part of the Galaxy and the magnetism is altered just enough that the density of the core of the earth becomes looser and it allows the crust of the earth to start slipping around like a skater on ice. In the same way magnetic filings can get tight and hard to move around in the presence of a magnet when you take that magnet away the magnetic the iron filings become loose and easy to kind of move around apparently.