The questions and methods of molecular biology and evolutionary biology are clearly distinct, yet a unified approach can lead to deep insights. Unfortunately, attempts to unify these approaches are fraught with pitfalls. In this informal series of questions and answers, we offer the mechanistically oriented biologist a set of steps to come up with evolutionarily reasonable and meaningful hypotheses. We emphasize the critical power and importance of carefully constructed null hypotheses, and we illustrate our ideas with examples representing a range (...) of topics, from the biology of aging, to protein structure, to speciation, and more. We also stress the importance of mathematics as the lingua franca for biologists of all stripes, and encourage mechanistic biologists to seek out quantitative collaborators to build explicit mathematical models, making their assumptions explicit, and their logic clear and testable. Biologists in all realms of inquiry stand to gain from strong bridges between our disciplines. (shrink)

Tinbergen’s classic “On Aims and Methods of Ethology” (_Zeitschrift für Tierpsychologie, 20_, 1963) proposed four levels of explanation of behavior, which he thought would soon apply to humans. This paper discusses the need for multilevel explanation; Huxley and Mayr’s prior models, and others that followed; Tinbergen’s differences with Lorenz on “the innate”; and Mayr’s ultimate/proximate distinction. It synthesizes these approaches with nine levels of explanation in three categories: phylogeny, natural selection, and genomics (ultimate causes); maturation, sensitive period effects, and routine (...) environmental effects (intermediate causes); and hormonal/metabolic processes, neural circuitry, and eliciting stimuli (proximate causes), as a respectful extension of Tinbergen’s levels. The proposed classification supports and builds on Tinbergen’s multilevel model and Mayr’s ultimate/proximate continuum, adding intermediate causes in accord with Tinbergen’s emphasis on ontogeny. It requires no modification of Standard Evolutionary Theory or The Modern Synthesis, but shows that much that critics claim was missing was in fact part of Neo-Darwinian theory (so named by J. Mark Baldwin in _The American Naturalist_ in 1896) all along, notably reciprocal causation in ontogeny, niche construction, cultural evolution, and multilevel selection. Updates of classical examples in ethology are offered at each of the nine levels, including the neuroethological and genomic findings Tinbergen foresaw. Finally, human examples are supplied at each level, fulfilling his hope of human applications as part of the biology of behavior. This broad ethological framework empowers us to explain human behavior—eventually completely—and vindicates the idea of human nature, and of humans as a part of nature. (shrink)

The scientific investigation of music requires contributions from a diverse array of disciplines. Given the diverse methodologies, interests and research targets of the disciplines involved, we argue that there is a plurality of legitimate research questions about music, necessitating a focus on integration. In light of this we recommend a pluralistic conception of music—that there is no unitary definition divorced from some discipline, research question or context. This has important implications for how the scientific study of music ought to proceed: (...) we show that some definitions are complementary, that is, they reflect different research interests and ought to be retained and, where possible, integrated, while others are antagonistic, they represent real empirical disagreement about music’s nature and how to account for it. We illustrate this in discussion of two related issues: questions about the evolutionary function of music, and questions of the innateness of music. These debates have been, in light of pluralism, misconceived. We suggest that, in both cases, scientists ought to proceed by constructing integrated models which take into account the dynamic interaction between different aspects of music. (shrink)

In The Secret of Our Success, Joseph Henrich claims that human beings are unique—different from all other animals—because we engage in cumulative cultural evolution. It is the technological and social products of cumulative cultural evolution, not the intrinsic rationality or ‘smartness’ of individual humans, that enable us to live in a huge range of different habitats, and to dominate most of the creatures who share those habitats with us. We are sympathetic to this general view, the latest expression of the (...) ‘California school’s’ view of cultural evolution, and impressed by the lively and interesting way that Henrich handles evidence from anthropology, economics, and many fields of biology. However, because we think it is time for cultural evolutionists to get down to details, this essay review raises questions about Henrich’s analysis of both the cognitive processes and the selection processes that contribute to cumulative cultural evolution. In the former case, we argue that cultural evolutionists need to make more extensive use of cognitive science, and to consider the evidence that mechanisms of cultural learning are products as well as processes of cultural evolution. In the latter case, we ask whether the California school is really serious about selection, or whether it is offering a merely ‘kinetic’ view of cultural evolution, and, assuming the former, outline four potential models of cultural selection that it would be helpful to distinguish more clearly. (shrink)

Günter Wagner’s Homology, Genes, and Evolutionary Innovation is a compelling, and empirically well-supported account of the evolution of character identity and character origination which emphasizes the importance of homology and novelty as central explananda for 21st century evolutionary biology. In this essay review, I focus on the similarities and differences between the structuralist picture of evolutionary biology advocated by Wagner, and that presented by standard evolutionary theory. First, I outline the ways in which Wagner’s genetic theory of homology diverges from (...) the account of homology offered by standard evolutionary theory. Then, I consider the motivations for these divergences. Lastly, I discuss a number of concerns with Wagner’s view, and offer some concluding thoughts on the relationship between structuralism and adaptationism. (shrink)

Ecological developmental biology considers the phenotype as actively produced through an environmentally informed process of individual development, rather than predetermined by the genotype. Accordingly, the genotype is viewed as one among many interactants that contribute formative elements; it is understood to do so no differently from the way other organism-internal and environmental resources do. Although the EcoDevo approach is evidently particularly apt to inform approaches to human development, which mostly takes shape in rich cultural environments, it is remarkable that, at (...) least within some highly influential circles of the linguistic sciences, the study of many distinctive human cognitive traits including language remains strongly anchored to a preformationist stance. This article brings an EcoDevo approach to the biologically focused study of language to argue that an aspect of language design commonly assumed to be “blueprinted,” namely, the lexicon-syntax interface, may instead be explained as a plastic effect of ongoing developmental processes in the mind of the child, in which designated aspects of the environment fulfill a key constructive role. (shrink)

According to the modern synthesis, evolution is the gradual change of gene frequencies in a population. The MS is closely allied to adaptationist explanations of phenotypes, where organismic form and behavior is treated as previously selected for and owes its genesis to some remote past. However, some new theories of evolution broadly aligned with the extended evolutionary synthesis, in particular developmental plasticity theory and niche construction theory, foreground the fact that evolution is sometimes much more rapid than previously imagined, and (...) occurs through the active engagement of organisms accommodating and modifying their environments. This article describes how these contemporary theories reveal two interconnected sides of being an adaptive subject, a situated agent that modifies itself and its environment as it lives, and contributes to evolution in turn. MS and adaptationism have a generic logical structure that can be taught anywhere, but because developmental plasticity theory and niche construction theory point to an ontology that foregrounds the agency of the organism, they benefit from in situ exploration. I argue biology as a subject needs to adapt, and call for the renewed importance of field studies, outlining some elements of how such studies might be conceived. I close by considering how understanding organisms as adaptive subjects of evolution has important implications for sustainability education. (shrink)

Physical cognition involves a host of cognitive abilities that enable understanding and manipulation of the physical world. Corvids, the bird family that includes crows, ravens and jays, are renowned for their cognitive abilities, but still little is known about their folk physics. This thesis explores the origins of physical cognition in corvids by investigating its mechanisms, development,fitness value and phylogeny in a wide context that includes theoretical and empirical studies.String pulling is a valuable paradigm for addressing these questions. Many animals (...) can pull a string with food attached to its end, but uncovering the cognitive abilities involved in this behaviour requires further testing. Paper I reviews the string-pulling paradigm, which is one of the oldest tests of animal cognition.It is a highly suitable test for species comparisons, socio-ecological correlations, and phylogenetic questions. Paper II tests several corvids, apes and peafowl on a string-pulling task where the first pulls do not result in the food moving closer. Despite the absence of such visual feedback, most subjects pulled strings in completely, although corvids appeared to choose randomly.Tool use is the archetypical example of physical cognition. Many corvids are remarkably adept at using tools in experimental settings. Paper III reviews animal tool use in general. It is now clear that customary tool-using species do not necessarily outperform their non-tool-using relatives on tests of physical cognition. For corvids that frequently use tools in the wild, such as New Caledonian crows and‘Alalā, tool use appears to have a significant fitness value and may have resulted in morphological adaptations. Paper IV describes a novel tool-use mode in New Caledonian crows. They inserted sticks into objects and then moved away,thereby transporting both. One crow could not grasp the target object, which suggests that such insert-and-transport tool use facilitates control over unwieldy objects. Paper V briefly argues that some corvids have shown the ability to make novel causal interventions, although this question should be addressed in a clearer theoretical framework that makes testable predictions.Sensorimotor cognition is a set of fundamental cognitive abilities that enables the integration of sensory and motor information into practical behaviour. It underlies much of corvid physical cognition. Paper VI investigates the development of sensorimotor cognition in ravens. Their skills developed rapidly and exceeded those of some mammals. They reached the same final sensorimotor stage as great apes, albeit at a markedly accelerated rate. The propensity of corvids to cache objects was investigated in Paper VII. Ravens, which often cache food,frequently cached objects, but surprisingly at similar rates as non-food-caching jackdaws. New Caledonian crows mostly cached objects that resembled functional tools.Anthropomorphism is the attribution of human traits to animals. Fear of mistakenly anthropomorphising animals has resulted in biased principles and an uneven burden of proof, which may hinder scientific progress more than it is supposed to offer protection against making mistakes. Cognitive zoology should not be misguided by overcompensating for such potential pitfalls. (shrink)