Earth Had Life From Its Infancy
Canadian rocks that are almost 4 billion years old contain signs that organisms were already around on the young planet.
The Torngat Mountains in northeastern Canada are full of life. Reindeer graze on lichen, polar bears prowl the coastlines, and great whales swim in the offshore waters. Scientists patrol the land, too, looking for the oldest rocks on the planet, which were formed almost 4 billion years ago, when the Earth was just an infant world.
Back then, the landscape would have been very different. The Earth was a hellish place that had only just acquired a firm crust. Its atmosphere was devoid of oxygen, and it was regularly pelted with asteroids. There were no life.