He is originally from Wisconsin, receiving his B.S from UW-Stevens Point and his M.S. and PhD. From UW-Milwaukee. He is an aquatic ecologist and studies mixotrophic algae in lakes. Courses that Dr. Holen has taught includes Evolution, Microbiology, Lake and Stream Ecology, Cell Biology and The Ecology of Infectious Disease. He has been actively involved with a grass roots group in the chemical monitoring of streams within a local watershed and is a researcher at the Lacawac Sanctuary, a wildlife refuge, environmental education center and biological field station located in the Poconos.