Life started with bacteria. By some cosmic chance, amino acids became DNA and proteins, which together became life. It took roughly 2 billion more years for things to get more interesting…but things got very, very interesting.
In this graphic by the Tree of Life web project and designer Leonard Eisenberg, we see all 3.5 billion years of life on earth evolving, not through limbs and timelines, but an elegant rainbow swirl. It’s as if our whole history is a colorful bunch of balloons, all tying back to bacteria.
As you look at the graphic, realize that time radiates outward and each kingdom’s appearance is also in chronological order from left to right. What you’ll discern then is a story of origins and mass extinctions, the way life almost bided its time through the Ice Age then hit the gas through the Cambrian Explosion. It was here when the protostomes (everything from trilobites to squids) simply went nuts, and the separation of plants vs. animals as we know them arose.
You’ll see lots of ideas that didn’t work–branches surrounded by small pockets of white or an extinct species. But mass extinctions, while often ending giving rise to new diversity, barely moved the needle on existing diversity. (This graph is constantly expanding, not shrinking). And of course, you’ll see the most important age to mankind, the mass extinction 65 million years ago that killed the dinosaurs and let the mammals have their day. That one did leave a pretty huge mark–a giant hole, in fact, in the branches.
Humans? We showed up about 63 million years later as one of the last bits of brown ink on the mammal branch–the smallest drop of pigment, but more than enough to wipe this beautiful rainbow away.