Erwin is Professor Emeritus at Northwestern University in the department of molecular biosciences. His work focuses on the molecular and cellular biology of mammalian sperm. In particular, his research focuses on a potential male contraceptive targeting lactate dehydrogenase C (LDH-C4), which ,when missing in sperm, makes it non-functional. This work has been regularly published in the journal Biology of Reproduction.
Erwin is a selected Fellow of the American Association for the Advancement of Science, and has received both the Distinguished Service Award and Distinguished Andrologist Award from the American Society of Andrology, and is a past president of the American Society of Andrology.