Your hands are, roughly speaking, 360 million years old. Before then, they were fins, which your fishy ancestors used to swim through oceans and rivers. Once those fins sprouted digits, they could propel your salamander-like ancestors across dry land. Fast forward 300 million years, and your hands had become fine-tuned for manipulations: your lemur-like ancestors used them to grab leaves and open up fruits. Within the past few million years, your hominin ancestors had fairly human hands, which they used to fashion tools for digging up tubers, butchering carcasses, and laying the groundwork for our global dominance today.

We know a fair amount about the transition from fins to hands thanks to the moderately mad obsession of paleontologists, who venture to inhospitable places around the Arctic where the best fossils from that period of our evolution are buried. (I wrote about some of those discoveries in my first book, At the Water’s Edge.)

Continue reading “Turning Fins Into Hands”

Slate is running a “pandemics” series, and I’m offering up the view from deep time. Koalas are getting hammered by a viral epidemic right now, and we’d do well to understand their woes. Because over the past 60 million years, we’ve experienced much the same thing, and it’s helped make us who we are today. Check it out.

Originally published December 6, 2012. Copyright 2012 Carl Zimmer.