Complex sentence: Paul left Baylor early, without completing either a biology or an English degree, when he was accepted into the Duke University School of Medicine, where he earned an M.D. in 1988, and completed his residency in 1993.
Split into simpler sentences: Paul left Baylor early, without completing either a biology or an English degree, when he was accepted into the Duke University School of Medicine. He earned a M.D. in 1988, and completed his residency in 1993.