Gregor Mendel
Notes
Gregor Mendel (1822–1884), Augustinian friar and abbot in Brno, who discovered the laws of inheritance by breeding pea plants and published them in 1866 in a paper nobody read. Rediscovered around 1900, his work supplied the particulate mechanism of heredity that Charles Darwin's theory lacked, and its union with natural selection in the 1930s and 1940s produced the Modern Synthesis. A useful example of a devout man doing science that undermined no part of his faith and much of other people's.
Wikipedia: https://en.wikipedia.org/wiki/Gregor_Mendel