What Hunted Lucy

Which brings us to Lucy.

Lucy is the most famous member of Australopithecus afarensis — a small, upright ape who walked the Ethiopian landscape about 3.2 million years ago. She stood roughly the height of a modern child, balanced on two legs, and carried a brain not much bigger than a chimpanzee's. Paleontologists found her in 1974 and named her after a Beatles song. We tend to picture her as a noble first chapter in the human story, gazing thoughtfully across the savanna.

New research suggests a more accurate picture: Lucy's world had teeth.

Scientists have identified a giant crocodile species that shared the rivers and lakeshores of Pliocene East Africa with creatures like her — a predator more than three million years old, built on a scale that makes the survivors of that ecosystem look less like protagonists and more like menu items. To something with that bite, an upright ape wading at the water's edge was not a milestone in the history of consciousness. It was a slow, soft, conveniently bipedal snack.

Here is the part worth sitting with. The animal that would eventually invent crocodile-conservation documentaries, riverside vacation rentals, and nature programming about apex predators spent the formative chapters of its existence as prey. The Taung Child, another early hominin, was almost certainly killed by an eagle — talon marks in the eye sockets gave it away. Big cats hunted our ancestors. Hyenas scavenged them. And, it turns out, enormous crocodiles were lying in wait at the one place a thirsty biped absolutely had to visit.

We did not climb to the top of the food chain. We crawled out of the middle of it, dripping, having spent millions of years being terrified of the dark for excellent reasons.

This is the cosmic joke embedded in your own body. The vigilance that keeps you up at 3 a.m. running threat assessments on an email you sent — that machinery was tuned over millions of years by things that genuinely wanted to eat the people you descend from. Your fear is not a malfunction. It is an heirloom. It worked. You are here because it worked, again and again, across a chain of ancestors so long it disappears into deep time, every single link of which managed not to be standing in the wrong shallows at the wrong moment.

There is something liberating in that, if you let it land. You are not the inevitable crown of creation, anxiously responsible for living up to billions of years of buildup. You are the wildly improbable, slightly waterlogged result of an unbroken streak of near-misses. The whole magnificent apparatus of human thought — philosophy, music, the capacity to read a sentence like this one — exists because a small ape kept not getting eaten by a very large reptile.

Lucy didn't know she was a beginning. She was just trying to get a drink without dying. Most of the time, her kind managed it. And here you are, three million years downstream, the proof.

Mind the water's edge. It's in your blood.