The anlagen of evo-devo in Fritz Müller's Für Darwin (1864)

Für Darwin, written in the early 1860s by the German zoologist and Darwinist Fritz Müller, articulates many of the concepts foundational to the contemporary field of evolutionary developmental biology, or evo-devo. Working on the Brazilian coast offered him refuge from both religious conservatism and the "great market" of Prussian academic science. Here, Müller studied the developmental stages of crustacea and used these meticulous observations to critique the extant literature on classification. In so doing, he both provided evidence for Darwin's theory, and extended it to larval forms. In this essay, we situate Für Darwin, published in English as Facts and Arguments for Darwin in 1869, within the landscape of nineteenth century biology. We propose that Für Darwin is a remarkably prophetic text in the history of developmental biology given its sharp insight into the relationship between development and evolution (ontogeny and phylogeny), its many contributions to crustacean biology, and Müller's deep appreciation of the danger of scientific dogma.