Joachim L. Dagg

ABSTRACT While Joseph Hooker was considering his upcoming presentation on the geographical distribution of species, he asked Charles Darwin for help with some references. During the ensuing exchange of correspondence, Darwin seems to have contradicted himself, regarding his being aware of Leopold von Buch’s observation that distributed varieties become species, prior to writing On the Origin of Species. Literalists and conspiracists have interpreted this apparent self-contradiction as a sign of duplicity and fraud. However, when the correspondence and Hooker’s address are analysed in context, there is a more compelling explanation. Simply that, in response to direct questioning by Hooker, Darwin conflated the two names of Von Baer and Von Buch, and made an honest mistake.

A historical episode of evolutionary theory, which has lead to the Red Queen theory of the evolutionary maintenance of sex, includes two striking contingencies. These are used to explore alternative what-if scenarios, in order to test some common opinions about such counterfactuals. This sheds new light on the nature of science and its historiography. One counterfactual leads to an unexpected convergence of its result to that of the actual science but, nevertheless, differs in its causal structure. The other diverges towards an incompatible alternative, but this requires further contingent choices that also diverge from actual science. The convergence in the first counterfactual is due to a horizontal transfer of knowledge. Similar transfers of knowledge are typical for innovations of actual science. This suggests that contingent choices can merge as well as fork research traditions both in actual research and counterfactual history. Neither the paths of the actual history of science nor those of its counterfactual alternatives will form a tree of exclusively diverging bifurcations, but a network instead. Convergencies in counterfactuals may, therefore, be due to the web-structure of science as much as to the aims of the historians in question. Furthermore, the difference in causal structure between the actual science and its convergent counterfactual might become diagnostic for external factors rather than internal aims forcing a historian towards convergence.

The so-called diet and patch models were foundational for evolutionary studies of foraging ecology. The diet model analyzed an organism’s choice between at least two different food or prey items. The patch model asked how much time a forager should invest in exploiting a resource patch that offered diminishing returns before moving on to search for another patch. Concerning sources of inspiration, however, some pioneers of optimal foraging theory explicitly denied an input from economics, others explicitly credited marginalist economics, while the majority remained tacit on this issue. An inquiry into the historical sources reveal an interesting patter. As far as diet is concerned, at least two models existed. One was the, probably homegrown, so-called contingency model of diet choice, the other was imported from marginal utility theory of economics. The import could not be operationalized in a way allowing predictions about feeding behavior. It was, therefore, used as a framework for interpreting data on food choices and gaining insights about the relative value of food items. The contingency model was hypothetico-deductive instead. It allowed predictions of behavior that could be tested. It was, therefore, the more popular among the peers and the pioneering publications have become citation classics, whereas the publications importing marginal utility theory int foraging ecology are largely forgotten. The situation is different for the patch model. At face value, only one homegrown model exists that was discovered independently at least twice. A closer look reveals obscure links suggesting knowledge dispersal from marginal productivity theory of economics towards optimal foraging or mating theory, respectively, along routes of private and unpublished communications. These communications were between alma mater and student in the case of Eric Charnov and between father and son, in the case of Geoffrey Parker. This study suggests two concusions: 1. models that are operationalized in a way allowing hypothetico-deductive research are more popular among researchers than others requiring a more inductive an interpretive approach. 2. The sciences are interlinked far more closely and deeply than mere citations would suggest. Sometimes a knowledge transfer that is crucial for a discovery can occur as an informal and private communication.

The group selection controversy largely focuses on altruism (e.g., Wilson 1983; Lloyd 2001; Shavit 2004; Okasha 2006, 173ff; Borrello 2010; Leigh 2010; Rosas 2010; Hamilton and Dimond in press). Multilevel selection theory is a resolution of this controversy. Whereas kin selection partitions inclusive fitness into direct and indirect components (via influencing the replication of copies of genes in other individuals), multilevel selection considers within-group and between-group components of fitness (Gardner et al. 2011; Lion et al. 2011). Two scenarios of multilevel selection are often distinguished (Damuth and Heisler 1988; Okasha 2006; Pigliucci 2010): (1) group structure only divides individual fitnesses into within- and between-group components (MLS1); and, (2) groups get their own component of fitness and also, in most definitions, a group-level adaptation (MLS2)

In 1935, A. G. Tansley, who was knighted later, proposed the ecosystem concept. Nevertheless, this concept was not without predecessors. Why did Tansley’s ecosystem prevail and not one of its competitors? The purpose of this article is to pin the distinguishing features of Tansley’s ecosystem down, as far as the published record allows. It is an exercise in finding the difference that made a difference. Besides being a pioneering ecologist, Tansley was an adept of psychoanalysis. His interest even led him to visit Sigmund Freud in Vienna for a while. Psychologists had to regard the mind as an entity in its own right, while knowing that it truly was part of a larger whole (body + mind), because the causal relation between body and mind was unknown. This lead Tansley to conclude that psychologists must not objectify the system under study, have to search for causes within their own field, and must not speculate unless this serves a scientific purpose. In 1925, Tansley defended psychoanalysis in a prolonged controversy against a concerted attack criticizing its speculative content and poor scientific standing. This could have been the reason why Tansley kept his ecosystem free of speculative content and unscientific connotation. The competing ecosystem-like concepts, however, have contained philosophical speculation, non-deterministic properties like vitalism or entelechy, or have been burdened with unscientific connotations. Hence, rigorous restraint distinguished the ecosystem concept and made it ready for use by later researchers.

Discussions of the implications of sexual reproduction have appeared throughout the history of evolutionary biology, from Darwin to Weismann, Fisher, Muller, Maynard Smith, and Williams. The latest of these appearances highlighted an evolutionary paradox that had previously been overlooked. In many animal and plant species reproduction is obligately sexual and also half the offspring are male, yet the males contribute nothing but genes to reproduction. If asexual mutants of such a species were to produce as many asexual offspring on average as sexual females in that species produce daughters and sons, the growth rate of their population would be twice as large. Whereas half the offspring of sexual females are noncontributory males, all the offspring of such an asexual mutant would contribute to growth rate. Nevertheless, sexual reproduction prevails in most species and is not lost evolutionarily.

Since intelligent design (ID) advocates claimed the ubiquitous mouse trap as an example of systems that cannot have evolved, mouse trap history is doubly relevant to studying material culture. On the one hand, debunking ID claims about mouse traps and, by implication, also about other irreducibly complex systems has a high educational value. On the other hand, a case study of mouse trap history may contribute insights to the academic discussion about material culture evolution. Michael Behe argued that mouse traps cannot trap mice with any part missing; therefore, they cannot have a precursor with one part less, therefore, cannot have a continuous history, and therefore, cannot have evolved. The patented and seminal precursor of current flat snap traps, however, had one part less, because spring and striker were formed of one wire. Secondly, historical records that reach back into the Bronze Age suggest that its history continued for a very long time. Thirdly, all prerequisites for evolution (variation, transmission, and selection) abound in mouse trap populations. Hence, Behe’s triple-jump conclusion about mouse traps is false each step. There is no, in principle, impossibility for mouse traps to evolve. An evolutionary account of mouse trap history also has academic merits beyond its educational value. Three important conclusions can be drawn: (1) reticulate phylogenies of artifact systems may be resolvable as overlapping, but branching, phylogenies of parts; (2) homologous ideas may be realized by analogous material, that is, phylogenies of information do not necessarily coincide with those of material parts; (3) recombination of parts between different artifact systems increases the cumulative nature of cultural evolution.