Nathaniel Southgate Shaler (February 20, 1841, Newport, Kentucky - April 10, 1906, Cambridge, Massachusetts) was an American paleontologist and geologist who wrote extensively on the theological and scientific implications of the theory of evolution.Born in 1841, Shaler studied at Harvard College's Lawrence Scientific School under Louis Agassiz. After graduating in 1862, Shaler went on to become a Harvard fixture in his own right, as lecturer (1868), professor of paleontology for two decades (1869-1888) and as professor of geology for nearly two more (1888-1906). Beginning in 1891, he was dean of the Lawrence School. Shaler was appointed director of the Kentucky Geological Survey in 1873, and devoted a part of each year until 1880 to that work. In 1884 he was appointed geologist to the U.S. Geological Survey in charge of the Atlantic division. He was commissioner of agriculture for Massachusetts at different times, and was president of the Geological Society of America in 1895. He also served two years as a Union officer in the American Civil War