Gregory Walter Graffin, Ph.D (born November 6, 1964) is an American punk rock singer-songwriter, multi-instrumentalist, college lecturer, and author. He is most recognized as the lead vocalist, songwriter, and only constant member of the noted Los Angeles band Bad Religion, which he co-founded in 1979. He also embarked on a solo career in 1997, when he released the album American Lesion. His follow-up album, Cold as the Clay was released nine years later. Graffin obtained his PhD at Cornell University and has lectured courses in life sciences and paleontology at the University of California, Los Angeles and evolution at Cornell University.