A biologist by training, Nico is interested in evolutionary biology, zoology, molecular ecology and environmental toxicology and has a long-term experience as teacher in these fields at the Vrije Universiteit Amsterdam. He was head of the Department of Ecological Science and served in the Faculty of Science Board as a vice-dean for Education. Nico was a supervisor for more than 70 PhD students. He has published 270 journal articles and 11 books, including textbooks on Ecological Genomics, Human Evolution & Development and Environmental Toxicology. His main study object has been the community of invertebrate animals living in soil, and their adaptation to soil pollution and interactions with microbes.