A new picture of life's history on Earth

Preliminary analysis of this database reveals interesting results, calling into question some fundamental ideas about the history of life on Earth.

Abstract

When most people think of paleontology, they picture the field paleontologist digging up fossils with a toothbrush and publishing descriptions of the anatomies of uncovered specimens in the trade literature. New discoveries of dinosaurs even make the national headlines. For many decades the discovery and description of a previously unknown fossil species was the calling card that gained would-be paleontologists professional acceptance. However, in the last quarter of a century or so, many of the most intriguing new results in paleontology have come not from field studies, but from the compilation and analysis of large-scale databases of fossil species. These databases have provided us with quantitative pictures of the pattern and size of mass extinction events, the rate at which new species have appeared, and crucially the number of species on the planet through time, the so-called standing diversity. In an article appearing in this issue of PNAS (1), John Alroy, Charles Marshall, and a large group of distinguished collaborators report on the creation of a new database that catalogs fossils at the level of individual collections. Preliminary analysis of this database reveals interesting results, calling into question some fundamental ideas about the history of life on Earth. John Alroy, Charles Marshall, and a large group of distinguished collaborators report on the creation of a new database that catalogs fossils at the level of individual collections.