John Dolan is a marine biologist at CNRS, University Paris VI, Villefranche-sur-Mer, France. His research subjects are organisms of the microzooplankton, the microscopic herbivores which are the first link in the aquatic food chain. He has worked in lakes, estuaries, and a variety of marine systems ranging from tropical lagoons to Anarctica. His speciality is ciliate microzooplankton. In recent years he has focused on the biodiversity of these organisms attempting to answer apparently simple question like ‘Why are there so many species of microzooplankton (there can be dozens in a liter of seawater)? Is each species doing a different thing?’ For more information, http://www.obs-vlfr.fr/~dolan/index.php.