Why Darwin and Wallace Disagreed About Domestic Varieties

By the late 1850s, Charles Darwin and Alfred Russel Wallace had independently formulated similar theories of evolution by natural selection, yet they diverged notably in their treatment of artificial selection. This difference, evident in their 1858 joint presentation to the Linnean Society, has sparked scholarly debate over whether it reflects a deep, enduring divergence or a more superficial misunderstanding. I argue that this difference reflects substantial disagreement, but not for the reasons traditionally offered. I argue that while both Darwin and Wallace acknowledged that artificial selection could lead to (i) traits shaped by the aesthetic preferences, whims, or novelty-seeking tendencies of human breeders, and (ii) organisms highly dependent on the artificial environments in which they were cultivated, they disagreed about whether natural selection could produce comparable outcomes. Darwin thought natural selection could, under certain conditions, yield traits and dependencies analogous to those seen in domesticated varieties, whereas Wallace denied that such parallels could be drawn. This difference, I argue, makes sense in light of their wider respective projects and goals. Finally, turning to the vexed and related question of whether Wallace accepted Darwin's argument by analogy, I agree with previous scholarship that Wallace could have accepted the cogency of Darwin's analogy, both in 1858 and at the time he wrote Darwinism in 1889, since this was consistent with his other theoretical commitments. But he certainly questioned the desirability of drawing such an analogy.