Smithsonian National Museum of Natural History

Alan Cheetham

Senior Scientist (Emeritus)

My research focuses on patterns of evolution in Cenozoic bryozoans at the finest scales of morphological and temporal resolution in order to test for consistency with the punctuated equilibria model versus the alternative model of phyletic gradualism, in which change is cumulative through a species' duration. The data with which my associates and I have tested this idea so far have come principally from cheilostome bryozoans in the Neogene of the Dominican Republic, Panama, Costa Rica, and Venezuela.

Department / Division
  • Ph.D. Columbia University, 1959
  • M.S. Louisiana State University, 1952
  • B.S. New Mexico Institute of Mining and Technology, 1950