Originally from the USA, Matthew Nielsen received his PhD at the University of Arizona (USA). Before joining the University of Bremen, he also worked at universities in Chapel Hill (USA), Stockholm (SE), and Oulu (FI). His research uses butterflies to understand how living things respond to the changes humans are making to our environment. He has studied how butterflies can evolve and adapt in response to climate change, and his current research focuses on how they are changing in cities across Europe, including Bremen. In this context, he also studies how living things can change within their lifetime (phenotypic plasticity) and how this ability itself evolves to suit new environments.