An ancient, colossal burst in the diversity of life may be attributable to an equally colossal shift in the distribution of Earth's land masses, researchers from the California Institute of Technology have proposed. Using paleontologic, geochemical, and geomagnetic data, magnetogeobiologist Joseph Kirschvink and colleagues have theorized that the “Cambrian Explosion” of life—a period about 500 million years ago when new types of plants and animals emerged at a rate 20 times the normal evolutionary rate—may have been caused by dramatic changes in the positions of Earth's continents.
“Life diversified like crazy about half a billion years ago, and nobody really knows why,” said Kirschvink. “It began 530 million years ago, and about 15 million years later life's diversity had stabilized at much higher levels. What actually happened is one of the outstanding mysteries of the biosphere.”