(abstracts will be uploaded here as they become available).
MONDAY 26th JUNE Evolvability of the explosive sea snake radiation Kate Sanders, Department of Ecology and Evolutionary Biology, The University of Adelaide My long term research aims to understand accelerated lineage and trait diversification rates in sea snakes. This involves a collaborative approach that links genotype (gene selection and chromosomal variations) to phenotype (demographic, life history, trophic and sensory traits) and environment (ecological opportunity and geographic factors). Using the culmination of my team’s findings, I will show how the organismal (specifically clade-based) framework contributes to our understanding of evolvability. I will draw attention to some traits – prey toxin resistance, shifts in colour vision - that conform to Mayr’s distinction between proximate and ultimate causes of change. However, most of my talk will focus on a key innovation in axial development that has triggered rapid and repeated body shape shifts in the explosively radiating Hydrophis clade. Morphological shifts are associated with colonisation of new dietary niches, and appear to facilitate lineage co-existence and diversity. I will explore the extent to which an organismal perspective and the concept of evolvability are needed to build a full biological understanding of lineage and trait evolution in this system.
Diversity and Unification: The Conceptual Roles of Evolvability across Disciplines Cristina Villegas, CFCUL, Universidade de Lisboa Biologists and philosophers have noted the diversity of interpretations of evolvability in contemporary evolutionary research. Different clusters of research identified by co-citation patterns or shared methodological orientation sometimes concentrate on distinct conceptions of evolvability. In this talk, I present a work where we examined five different activities where the notion of evolvability plays conceptual roles in evolutionary biological investigation: setting a research agenda, characterization, explanation, prediction, and control. Our analysis of representative examples demonstrates how different conceptual roles of evolvability are quasi-independent and yet exhibit important relationships across scientific activities. It also provides resources to detail two distinct strategies for how evolvability can help synthesize disparate areas of research and thereby potentially serve as a unifying concept in evolutionary biology.
Causes, Contributors, and Determinants of Evolvability Aja Watkins, Department of Philosophy, University of Wisconsin-Madison Abstract: This talk will focus on the causes of evolvability (sometimes called contributors to or determinants of it). After discussing some questions that arise in a conceptual analysis of evolvability, such as whether evolvability should be relative to a particular trait, timescale, or broad/narrow scope, I will explicate and evaluate some existing proposals for factors that determine or contribute to a lineage’s evolvability. These include especially features of development, namely: “modularity, flexibility, and the hierarchical organization of development by genetically complex switches” (West Eberhard 2003). For each of these, I will explain why it is plausible that they contribute to evolvability, and also how each might be measured as a means of predicting evolvability. Finally, in conclusion, I will zoom out to address the question of why we might be interested in measuring or predicting evolvability, which, I argue, relates to setting priorities in conservation research and policy.
TUESDAY 27th JUNE A Causal Account of Evolvability Katie Deaven, Department of Philosophy, University of Wisconsin-Madison Recent work on the concept of evolvability suggests that it may be best understood as an evolutionary factor, comparable to drift and selection, that is multiply realizable by many different morphological and physiological properties of individual organisms. Drawing on the so-called “causalists’s” defense of selection (and drift) as higher-order causes and the literature in philosophy of mind concerning multiply realizable dispositions, I explore whether evolvability can earn its keep alongside these other purported higher-level causes. There is a significant explanatory payoff if evolvability can meet these challenges: we want to be able to make generalizable claims about evolvability that support counterfactuals and we can do so if evolvability has a distinct causal signature that we can identify. However, whether the concept of evolvability can meet these challenges remains to be seen.
Causation, state spaces, evolvability, and creativity Charles H. Pence, Institut supérieur de philosophie, Université catholique de Louvain Philosophers of biology have long been divided over how to interpret the idea that evolution is a “creative” process. Is natural selection itself somehow creative, or is mutation rather the engine of creation, with natural selection playing the role of a kind of negative filter of deleterious variation? Evolvability seems intimately related to this sense of “creativity,” at the very least insofar as the two are what we might call “second-order” properties of evolutionary trajectories over time. In this talk, I will use some of my own recent work on causation in natural selection, which considers the state spaces through which evolution moves individuals and populations, to try to shed some (highly speculative) light on what it might mean for evolution to (be susceptible to) produce genuine novelty.
Signatures of phenotypic plasticity in adaptive evolution Dan Noble, Research School of Biology ANU Phenotypic responses to challenging new environments are often initially plastic. Following strong selection, phenotypes can then be refined and reinforced through genetic change. ‘Plasticity-first’ scenarios of adaptive evolution are discussed widely but only a few model systems provide sufficient evidence supporting plasticity first hypotheses. I’ll discuss two meta-analyses that quantify the degree of developmental bias in phenotypic plasticity and how plasticity leaves phenotypic signatures during local adaptation.
Reciprocal Causation and Biological Practice Caleb Hazelwood, Department of Philosophy, Duke University Arguments for an extended evolutionary synthesis often center on the concept of “reciprocal causation.” Proponents argue that reciprocal causation is superior to standard models of evolutionary causation for at least two reasons. First, it leads to better scientific models with more predictive power. Second, it more accurately represents the causal structure of the biological world. Simply put, proponents of an extended evolutionary synthesis argue that reciprocal causation is empirically and explanatorily apt relative to competing causal frameworks. In this paper, I present quantitative survey data from faculty members in biology departments at universities across the United States to evaluate this claim. The survey data indicate that a majority of the participants do not agree (i.e., most either disagree or neither agree nor disagree) that the concept of reciprocal causation confers a larger advantage on research practices. However, a majority of the participants agree that the causal framework of the extended evolutionary synthesis more accurately represents the structure of the biological world. These results demonstrate that the explanatory merits of a conceptual framework and its practical utility can come apart in interesting and informative ways.
WEDNESDAY 28th JUNE The proximate and ultimate causes of the origin of animals. Maja Adamska, Research School of Biology, ANU While the origin of animals is only one of many major transitions in evolution, it is perhaps the one most relatable – and fiercely debated – from the human perspective. Since the 19th century, three groups of organisms have been considered key to the understanding of how and why the complex animals evolved: cnidarians (corals and jellyfish), which are morphologically the simplest animals with nerves and muscle; sponges, nerve-less and muscle-less filter feeders, and choanoflagellates, which are single-cell and colonial protists looking just like choanocytes – cells which in sponges are responsible for capturing bacteria. The last decade brought technological advances that were hoped to clarify the steps leading to evolution of complex animals. Yet, it turns out that gene and genome-based phylogenies and the analyses of cell-type specific transcriptomes support conflicting scenarios of emergence of animal multicellularity. In my talk, I will present the recent insights into the early steps of animal evolution and discuss the potential role of plasticity in enabling the emergence of complex animals.
Transitional thinking in cognitive evolution Colin Klein, School of Philosophy, Australian National University The evolutionary history of animal cognition appears to involve a few major transitions: that is, major changes that opened up new phylogenetic possibilities for cognition.I review and contrast current transitional accounts of cognitive evolution, arguing that an important feature of an evolutionary transition should be that it changes what is evolvable. I discuss an effort to develop an account of cognitive evolution that focusses on how selection might act on the computational architecture of nervous systems. Selection for operational efficiency or robustness can drive changes in computational architecture that then make new types of cognition evolvable. We propose five major transitions in the evolution of animal nervous systems. Each of these gave rise to a different type of computational architecture that changed the evolvability of a lineage and allowed the evolution of new cognitive capacities. Transitional accounts have value in that they allow a big-picture perspective of macroevolution by focusing on changes that have had major consequences. For cognitive evolution, however, I will argue that it is most useful to focus on evolutionary changes to the nervous system that changed what is evolvable, rather than to focus on changes in specific cognitive capacities.
Lessons from the Major Transitions Debate for Evolvability Rachael Brown, School of Philosophy, ANU The decades since Maynard-Smith and Szathmáry’s The Major Transitions in Evolution (1995) have seen evolutionary events ranging from the origin of hot-bloodedness (Araujo et al. 2022), to the origin of human cultural groups (Szathmáry 2015), and the biological oxygenation of the Earth (O’Malley & Powell 2016) labelled as “major transitions”. So disparate has the range of evolutionary events become that some (e.g., McShea & Simpson 2011) question the value of “major transition” talk altogether. Others (e.g., Herron 2021, Okasha 2022) argue we should limit the label “major transition” to only those events concerning the origin of new types of evolutionary individual. In this paper, I attempt to walk the middle ground between these two extremes, exploring the respectability of a broader notion of the Major Transitions based in evolvability. Ultimately I argue for a type of pluralism: there are several types of “major transition”, which are of value in discussions of macroevolutionary patterns and the contingent nature of evolution. This discussion has important implications for understanding evolvability and the relationship between evolvability, selection and drift.