What caused the Cambrian “explosion”?

Question of the Week, 22.11.2010

In the early Cambrian, approximately 540 million years ago, the pace of evolution became exceptionally fast and almost all modern animal phyla emerged during a geologically short time period of not more than 70 million years. It has been tried to explain this “Cambrian explosion” on the basis of environmental or developmental changes but a generally accepted hypothesis has not yet been established.

Further reading:

Marshall, C. R., Explaining the Cambrian “Explosion of Animals”, Annu. Rev. Earth Planet. Sci. 34, 355–384 (2006). doi:10.1146/annurev.earth.33.031504.103001

Thomas Jagau