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)

In 1853, the young Thomas Henry Huxley published a long review of German cell theory in which he roundly criticized the basic tenets of the Schleiden-Schwann model of the cell. Although historians of cytology have dismissed Huxley's criticism as based on an erroneous interpretation of cell physiology, the review is better understood as a contribution to embryology. "The Cell-theory" presents Huxley's "epigenetic" interpretation of histological organization emerging from changes in the protoplasm to replace the "preformationist" cell theory of Schleiden and (...) Schwann (as modified by Albert von Kölliker), which posited the nucleus as the seat of organic vitality. Huxley's views influenced a number of British biologists, who continued to oppose German cell theory well into the twentieth century. Yet Huxley was pivotal in introducing the new German program of "scientific zoology" to Britain in the early 1850s, championing its empiricist methodology as a means to enact broad disciplinary and institutional reforms in British natural history. (shrink)