Against the common historiographic narratives of evolutionary biology, the first decades of the 20th century were theoretically far richer than usually assumed. This especially refers to the hitherto neglected role that early theoretical biologists played in introducing visionary research perspectives and concepts before the institutionalization of the Modern Synthesis. Here, we present one of these scholars, the German theoretical biologist and ecomorphologist Hans Böker, by reviewing his 1935 paper “Artumwandlung durch Umkonstruktion, Umkonstruktion durch aktives Reagieren der Organismen”, published in the (...) inaugural volume of the journal Acta Biotheoretica. While largely forgotten today, this work represents a melting pot of ideas that adumbrate some of today’s most lively debated empirical and conceptual topics in evolutionary biology: the active role of organisms as actors of their own evolution, environmental induction and phenotypic plasticity, genetic assimilation, as well as developmental bias. We discuss Böker’s views on how species change through "Umkonstruktion," and how such reconstruction is exerted through active reactions of organisms to environmental perturbations. In addition, we outline the aims and wider context of his "biological comparative anatomy," including Boker’s reprehensible political affiliation with the Nazi Party. Finally, we highlight some of the historical reasons for why Böker’s views did not have a larger impact in evolutionary biology, but we also recount some of the direct and indirect legacies of his approach in research areas such as ecomorphology and EvoDevo. Böker’s paper is available as supplementary material in the online version of this article, as part of the journal's "Classics in Biological Theory" collection; the first translation of the paper into English, by Alexander Böhm and Jan Baedke, is also being published in this volume. (shrink)

Adolf Meyer-Abich spent his career as one of the most vigorous and varied advocates in the biological sciences. Primarily a philosophical proponent of holistic thought in biology, he also sought through collaboration with empirically oriented colleagues in biology, medicine, and even physics to develop arguments against mechanistic and reductionistic positions in the life sciences, and to integrate them into a newly disciplinary theoretical biology. He participated in major publishing efforts including the founding of Acta Biotheoretica. He also sought international contacts (...) and worked for long stretches in Chile, the Dominican Republic, El Salvador, and the United States. His career straddled the Nazi period, which led him into a complex dance of support for and resistance to the regime. Despite the relative failure of his conceptual innovations to catch on, his ideas and writings sit squarely within the trajectory of thought and argument that has led to today’s reinvigoration of thought about conceptual integration in evolutionary developmental biology. (shrink)