Life on Earth

Life arose on planet Earth perhaps more than 4 billion years ago. There’s one claim of identifiable signatures of life dated to 4.1 billion years ago. Another one claims actual microfossils at 4.28 billion years ago. The earliest evidence of life that’s generally accepted are stromatolites, rocky deposits left by mats of bacteria, dating from 3.48 billion years ago.

I’ve wanted to be able visualize the sweep of life over Earth’s history. Here’s my first attempt at that.

After the Cambrian Explosion, when multi-cellular life with structures that made good fossils arose 570 million years ago, we have the basis for a science of Biogeography. This is intimately tied to the movement of Earth’s plates and continents, Continental Drift. Here’s an attempt to view the last 540 million years of that drift.