Complex sentence: Her father, Milton Terra, was a professor of environmental science at University of Calgary who is perhaps best known for his publications disproving the original estimates of environmental damage provided by Exxon Shipping Co. after the Exxon Valdez Oil Spill in 1989.
Split into simpler sentences: Her father, Milton Terra, was a professor of environmental science at the University of Calgary. He is perhaps best known for his publications disproving the original estimates of environmental damage provided by Exxon Shipping Co. after the Exxon Valdez Oil Spill in 1989.