A well-established narrative in the history of science has it that the years around 1800 saw the end of a purely descriptive, classificatory and static natural history. The emergence of a temporal understanding of nature and the new developmental-history approach, it is thought, permitted the formation of modern biology. This paper questions that historical narrative by closely analysing the concepts of development, history and time set out in Karl Ernst von Baer’s study of the mammalian egg (1827). I show that (...) Baer’s research on embryogenesis aimed not simply to explain temporal changes, but to inscribe the formation of new individual organisms into a continuous, unending organic process. I confront Baer’s views with other explanations of embryogenesis arising in the 1820s and 1830s, especially those of Jean-Baptiste Dumas and Jean-Louis Prévost and of Theodor Schwann. By highlighting divergences between these scientists, especially as to their view of the role of gender differences in reproduction, I argue that biology evolved not from a homogeneous concept of developmental history but out of various, even opposing, views and research programmes. Thus, the birth of biology did not imply the end of all natural history’s thought models. (shrink)

Modern biology is ambivalent about the notion of evolutionary progress. Although most evolutionists imply in their writings that they still understand large-scale macroevolution as a somewhat progressive process, the use of the term “progress” is increasingly criticized and avoided. The paper shows that this ambivalence has a long history and results mainly from three problems: (1) The term “progress” carries historical, theoretical and social implications which are not congruent with modern knowledge of the course of evolution; (2) An incongruence exists (...) between the notion of progress and Darwin’s theory of selection; (3) It is still not possible to give more than a rudimentary definition of the general patterns that were generated during the macroevolution of organisms. The paper consists of two parts: the first is a historical overview of the roots of the term “progress” in evolutionary biology, the second discusses epistemological, ontological and empirical problems. It is stated that the term has so far served as a metaphor for general patterns generated amongst organisms during evolution. It is proposed that a reformulation is needed to eliminate historically imported implications and that it is necessary to develop a concept for an appropriate empirical description of macroevolutionary patterns. This is the third way between, on the one hand, using the term indiscriminately and, on the other hand, ignoring the general patterns that evolution has produced. (shrink)