Setting the Scene: Milestones in the Search for Early Life on Earth

Some 150 years ago, Charles Darwin was greatly puzzled by a seeming absence of fossils in rocks older than the Cambrian period (Darwin, 1859). He drew attention to a veritable Lost World that we now know to have spanned more than 80% of Earth History. To put our modern evidence and thinking about Precambrian life into perspective, this introduction will reflect upon the development of three key ideas in this field: the Victorian Eozoon controversy, the ongoing stromatolite debate, and the recent Apex microfossil debate.

“How on Earth did life begin?” This is one of the noblest questions we can ask in science. But it took well over a century from 159 to gain an understanding of life in the Precambrian — the world before the Cambrian explosion of animals. Why did an understanding take so long? Arguably it was because it was, and still remains, a very big and very difficult problem. Its study now involves the whole of the natural sciences. Progress has been a matter of slow attrition. For most of this time, for example, there has been no concept of the vast duration of Precambrian time, nor any evidence for a distinct biota.