Stop 2. Life, land, and the first humans

Follow the yellow wedge down to strip 2. It takes the last sliver of strip 1, the last 600 million years, and stretches it across the page.

Plants reach land about 470 million years ago. Animals walk on land by about 390 million years ago, judging by their tracks. The dinosaurs end 66 million years ago, when an asteroid hits what is now Mexico.

Follow the next wedge to strip 3, the last 3 million years. The oldest jaw that scientists place in our genus, Homo, is about 2.8 million years old. It was found in Ethiopia. Homo erectus appears about 2 million years ago and leaves Africa soon after.

You may have heard "humans, one million years." That is not the standard date. By a million years ago, people of the genus Homo were already living in Europe. Our own species, Homo sapiens, is about 315,000 years old. The oldest fossils come from Morocco. Modern humans spread across the world between about 70,000 and 50,000 years ago.

When was Adam? The record does not date him, and Genesis gives no year for him in any way the record can check. The views do not agree. Chart 2 shows where each one puts him.

Picture: Chart 1, strips 2 and 3.