1. Charles R. Darwin, On the Origin of Species by Means of Natural Selection, or the Preservation of the Favored Races in the Struggle for Life (London: John Murray, 1859).
2. Stephen Jay Gould, The Mismeasure of Man (New York: W. W. Norton, 1981).
3. Francis Bacon, The Advancement of Learning (London: W. Washington, 1695).
4. See, for example, Peter J. Bowler, Theories of Human Evolution: A Century of Debates, 1844–1944 (Baltimore: Johns Hopkins University Press, 1986).
5. Karl Popper, The Logic of Scientific Discovery (New York: Harper & Row, 1968).