His main interest focuses on evolution of semantic organs; evolutionary psychology, development of comparative concepts in biology, theoretical biology, biosemiotics, and philosophy and history of biology in general. He published 23 original papers, seven book chapters, 13 contributions in edited volumes, reviews, popular papers etc., and he is also an author of one co-authored and two edited books. Currently, Kleisner is an editorial board member of the international peer-reviewed journal Biosemiotics (Springer) and board member of the Governing Committee of the International Society of Biosemiotic Studies.