Summary1. When a species experiences a new climate, it can adapt in two main ways: become genetically adapted to the new temperature, or adopt a plastic approach that allows it to survive at a range of temperatures. 2. The constraint on fitness for genetically adapted populations that are exposed to a new temperature has been well studied, but the range of optimal temperatures and their effect on fitness has never been examined across the worldwide distribution of a plastic species. 3. Here, we determined the optimum temperature range of 11 populations of the phenotypically plastic species Drosophila simulans. We measured the influence of temperature on eggs, larvae and adults at six temperatures that span the natural range the flies experience during their primary breeding season. 4. We found no correlation between optimum temperature and native temperature, an effect that is not likely due to laboratory maintenance, suggesting that the species has not locally adapted to temperature. We also found that this species had equal survival and reproductive success at most of the temperatures and life stages that we tested, regardless of the native temperature where the flies originated. 5. Thus, this genetically plastic species has an optimum fitness at a surprisingly wide range of temperatures, and is the first example of a cosmopolitan species exhibiting this large amount of plasticity across its sampling distribution.

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Thermal adaptation is typically detected by examining the tolerance of a few populations to extreme temperatures within a single life stage. However, the extent to which adaptation occurs among many different populations might depend on the tolerance of multiple life stages and the average temperature range that the population experiences. Here, we examined local adaptation to native temperature conditions in eleven populations of the well‐known cosmopolitan fruit fly, Drosophila melanogaster. These populations were sampled from across the global range of D. melanogaster. We measured traits related to fitness during each life stage to determine whether certain stages are more sensitive to changes in temperature than others. D. melanogaster appeared to show local adaptation to native temperatures during the egg, larval and adult life stages, but not the pupal stage. This suggests that across the entire distribution of D. melanogaster, certain life stages might be locally adapted to native temperatures, whereas other stages might use phenotypic plasticity or tolerance to a wide range of temperatures experienced in the native environment of this species.

Evolutionary developmental biology (evo-devo) represents a paradigm shift in the understanding of the ontogenesis and evolutionary progression of the denizens of the natural world. Given the empirical successes of the evo-devo framework, and its now widespread acceptance, a timely and important task for the philosophy of biology is to critically discern the ontological commitments of that framework and assess whether and to what extent our current metaphysical models are able to accommodate them. In this paper, I argue that one particular model is a natural fit: an ontology of dispositional properties coherently and adequately captures the crucial casual-cum-explanatory role that the fundamental elements of evodevo play within that framework.The recent advent of evolutionary developmental biology (evo-devo) has ushered in a novel conception of the organism and its place in the biological world, one which has substantially built upon the theoretical framework of the Modern Synthesis by offering new perspectives on the nature of both ontogenesis and evolution. In contrast to the crude reductionism of genocentrism, evo-devo places emergent, epigenetic, environmentally-sensitive causal factors at the explanatory centre of morphogenesis. And although population-level, allele frequency-based explanations are no doubt explanatory with respect to the evolutionary process of natural selection, evo-devo"s unique focus on the developmental mechanisms which intrinsically constrain and shape morphology paints a colourful and powerful new picture of that process. Given the potential gestalt-shift inherent in the framework of evo-devo, it is instructive now to reflect on whether and to what extent our current philosophical concepts are able to coherently and adequately model that framework and its accompanying empirical and experimental data -a question that has yet to be given serious philosophical attention. 1 What I want to suggest is that capturing the ontology of evo-devo is a task that ought to be performed by putting to service the contemporary philosophical framework of dispositional properties. My claim is that the integrated causal-cum-explanatory role that the elements central to the framework of evo-devo play with respect to ontogenesis and evolutionary progression is one that is adequately and sufficiently captured by the theoretical nature of dispositional properties. Evo-devo is, or so I will argue, a science of dispositions. A Contemporary Conception of Dispositional PropertiesIn order to substantiate that claim, we"ll need to first have a firm grip on the nature of dispositional properties. Of course, given the size of the contemporary literature on dispositions, there is quite a lot of variation in the particulars here -but rather than comparing and contrasting the merits of various specific accounts, what I want to do below is to draw out a few of what I consider the most important and defining features of these properties, ones which I think, for all practical purposes, function as the "lowest commo...

The advent of contemporary evolutionary theory ushered in the eventual decline of Aristotelian Essentialism (AE) -for it is widely assumed that essence does not, and cannot have any proper place in the age of evolution. This paper argues that this assumption is a mistake: if AE can be suitably evolved, it need not face extinction. In it, I claim that if that theory"s fundamental ontology consists of dispositional properties, and if its characteristic metaphysical machinery is interpreted within the framework of contemporary evolutionary developmental biology, an evolved essentialism is available. The reformulated theory of AE offered in this paper not only fails to fall prey to the typical collection of criticisms, but is also independently both theoretically and empirically plausible. The paper contends that, properly understood, essence belongs in the age of evolution.Within contemporary philosophy of biology, there is perhaps no greater maligned theory than Aristotelian Essentialism (AE). Now that the rosy dawn of Aristotelian metaphysics has faded into twilight 1 , citing the essence of an organism as an explanatory principle is indicative either of a rather hopeless scientific naiveté or else a dogmatic entrenchment in scholasticism. It is generally agreed that the sun set upon AE for a simple, yet powerful reason: the advent of evolutionary theory. According to the implications of that theory, kind-essences are an ontological superfluity which the world not only has no need of, but simply cannot countenance. However, evolutionary theory has recently had its own paradigm shift, ushered in with the rise of the union between it and developmental theory. With its increasing emphasis on modular, structural explanations of morphological novelty and variation, evolutionary developmental biology (evodevo) has arguably prompted a substantial reshaping of our understanding of the very nature of biological individuals. In light of this reformation, the question naturally arises: what is it to be the what-it-is-to-be of an organism? In what follows, I suggest that the answer to that question is one best interpreted within the ontological framework of AE. I contend that, properly understood, essence belongs in the age of evolution. Aristotelian Essentialism vs. Evolution First things first: what exactly is AE?One can find many distinct (though often overlapping) definitions in the literature, but here, for the sake of simplicity, and without wishing to rehearse decades of debate, I focus on a simple three-point definition. An Aristotelian essence is (a) comprised of a natural set of intrinsic properties which (b) constitute generative mechanisms for particularised morphological development which (c) are shared among groups of organisms, delineating them as members of the same "kind". Regarding (a), the set of properties that comprise an essence and define a natural kind cannot be extrinsic, or relational properties -abstract properties of phylogenetic lineage or interbreeding relations, etc. -and their being a ...