4

Lakes could easily have been created that were held in place only by glaciers or rubble dams, which naturally, as glaciers melted or levels again rose, would give way as water pressure overpowered them.

3

Archeologists and paleo-biologists recount stories of mass extinction events in the distant past, triggered by natural events, but humanity, it would apear, is making such a megative impact on the planet that we are creating yet another.

12

We may never get to see the true offspring of this incredible plant, which was the home of dinosaurs once, when forests of it covered large parts of the globe.