He went to Wausau West High School and then to the University of Wisconsin in Madison and graduated with a degree in science education.
He later graduated from Purdue in 1985 and became an Andrew Mellon Fellow at Stanford working on Biological Invasions with Harold Mooney.
In 1986, he began teaching at The University of Tennessee as an assistant professor in zoology and the ecology graduate program.
[3] Some of his work included sequential and spatial constraints to illustrate the principles of population ecology.
His most influential work involves emerging complex systems, food webs, and biological invasions.