French naturalist Georges-Louis Leclerc, Comte de Buffon (1707–1788) was an early proponent of natural history, which is the study of plants and animals in their natural settings. He was also known for his work as a mathematician. Buffon was interested in the modes by which evolutionary change could occur. A prolific writer (his work Natural History comprised thirty-five volumes), he pondered the meaning of the term “species” and whether such groupings were immutable (unchanging) over time. In addition, he served as mentor to French naturalist Jean-Baptiste de Lamarck (1744–1829).