Kalevi Kull (b. 1952) has graduated the University of Tartu as a biologist in 1975. He has worked many years as a field ecologist. His earlier work dealt with ethology, and later with experimental plant ecology. He has studied the mechanisms of species coexistence in species-rich communities, and developed mathematical modelling in ecophysiology. Since 1975, he has been the main organiser of annual meetings of theoretical biology in Estonia. In 1992, he became a Professor of Ecophysiology in the University of Tartu. In 1997, he joined the Department of Semiotics, and became a Professor in Biosemiotics in 2007. Since 2006, he is the Head of the Department of Semiotics in the University of Tartu, Estonia. His field of interests include biosemiotics, ecosemiotics, general semiotics, theoretical biology, history and philosophy of life science. His publications include a number of papers in the journals Semiotica, Sign Systems Studies, Biosemiotics, Cybernetics and Human Knowing, European Journal of Semiotics, etc., and edited or co-edited volumes, including Lectures in Theoretical Biology; Jakob von Uexküll: A paradigm for semiotics and biology; Imagining Nature; Towards a Semiotic Biology: Life is the Action of Signs, etc. He is an editor of the journal Sign Systems Studies since 1998, and coeditor (with Paul Cobley) of book series Semiotics, Communication, Cognition (Mouton de Gruyter) and Biosemiotics (Springer). He has been one of the founders of the Jakob von Uexküll Centre. He is a honorary member of the Semiotic Society of America.