An evolutionary biologist, he is a professor at Jagiellonian University, specializing in the study of symbioses between insects and bacteria. His work examines how microorganisms influence the biology, evolution and ecology of their hosts. He is particularly interested in the complex interspecies relationships that shape biodiversity and the functioning of ecosystems. He was previously affiliated with the University of Oxford and the University of Montana, where he conducted research on the symbiotic bacteria of aphids and bugs. His work combines modern methods of molecular biology, genomics and evolutionary ecology to understand how relationships between organisms emerge, stabilize and change.