3,603 research outputs found

    From Evo to EvoDevo: Mapping and Adaptation in Artificial Development

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    Understanding evolutionary processes during past Quaternary climatic cycles: Can it be applied to the future?

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    Climate change affected ecological community make-up during the Quaternary which was probably both the cause of, and was caused by, evolutionary processes such as species evolution, adaptation and extinction of species and populations

    a variational approach to niche construction

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    In evolutionary biology, niche construction is sometimes described as a genuine evolutionary process whereby organisms, through their activities and regulatory mechanisms, modify their environment such as to steer their own evolutionary trajectory, and that of other species. There is ongoing debate, however, on the extent to which niche construction ought to be considered a bona fide evolutionary force, on a par with natural selection. Recent formulations of the variational free-energy principle as applied to the life sciences describe the properties of living systems, and their selection in evolution, in terms of variational inference. We argue that niche construction can be described using a variational approach. We propose new arguments to support the niche construction perspective, and to extend the variational approach to niche construction to current perspectives in various scientific fields

    Dynamicity and Performance in Adaptive Organizations

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    In this dissertation, I focus on the conceptualization and empirical investigation of organizational adaptation. Specifically, I intend to study how dynamic organizations evolve and under which conditions they successfully adapt to a changing environment. In essay 1 (with D. Levinthal), we develop a simulation model to clarify and explore some of the basic conceptual issues concerning the dynamics through which business practices locally adapt within an intra-organizational ecology of organizational level skills, knowledge, and capabilities subject to processes of mutation and selection. For essay 2 (with A. Prencipe), we designed and conducted a field project by collecting qualitative data: a mix of archival data, interviews and ethnographic field notes. The main goal is to investigate how organizational adaptation plays out under the pressure of various institutional forces. Our findings illustrate that institutional forces generate selective reactions within the ecology of existing organizational routines. Conversely, non-institutional forces adapt to the existing behavioral forms following a two-way dynamic process. In essay 3, I developed an empirical research design based on a panel data analysis to investigate the role of dynamic capabilities in boosting adaptation performance. This work examines some of the fundamental contingencies that impact the relationship between dynamic capabilities and organizational performance. Specifically, although prior experience in product adaptation is considered as a key driver of superior performance, its value is found to be highly conditional on both the level of focal activity - a recent adaptation effort on specific activities - and the intensity of the environmental changes

    Animal learning as a source of developmental bias

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    Research supported in part by a grant from the John Templeton Foundation to K. N. L. (“Putting the extended evolutionary synthesis to the test”, ref 60501), by Japan Society for the Promotion of Science KAKENHI to W. T. (ref 17J01559), and a grant from the Netherlands Organization for Scientific Research to T. O. (ref 019.172EN.011).As a form of adaptive plasticity that allows organisms to shift their phenotype toward the optimum, learning is inherently a source of developmental bias. Learning may be of particular significance to the evolutionary biology community because it allows animals to generate adaptively biased novel behavior tuned to the environment and, through social learning, to propagate behavioral traits to other individuals, also in an adaptively biased manner. We describe several types of developmental bias manifest in learning, including an adaptive bias, historical bias, origination bias, and transmission bias, stressing that these can influence evolutionary dynamics through generating nonrandom phenotypic variation and/or nonrandom environmental states. Theoretical models and empirical data have established that learning can impose direction on adaptive evolution, affect evolutionary rates (both speeding up and slowing down responses to selection under different conditions) and outcomes, influence the probability of populations reaching global optimum, and affect evolvability. Learning is characterized by highly specific, path‐dependent interactions with the (social and physical) environment, often resulting in new phenotypic outcomes. Consequently, learning regularly introduces novelty into phenotype space. These considerations imply that learning may commonly generate plasticity first evolution.PostprintPeer reviewe

    Developmental, morphological, and behavioural plasticity in the reproductive strategies of stink bugs and their egg parasitoids

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    L’environnement façonne la physiologie, la morphologie et le comportement des organismes par l’entremise de processus Ă©cologiques et Ă©volutifs complexes et multidimensionnels. Le succĂšs reproducteur des animaux est dĂ©terminĂ© par la valeur adaptative d’un phĂ©notype dans un environnement en modification constante selon une Ă©chelle temporelle d’une Ă  plusieurs gĂ©nĂ©rations. De plus, les phĂ©notypes sont façonnĂ©s par l’environnement, ce qui entraine des modifications adaptatives des stratĂ©gies de reproduction tout en imposant des contraintes. Dans cette thĂšse, considĂ©rant des punaises et leurs parasitoĂŻdes comme organismes modĂšles, j’ai investiguĂ© comment plusieurs types de plasticitĂ© peuvent interagir pour influencer la valeur adaptative, et comment la plasticitĂ© des stratĂ©gies de reproduction rĂ©pond Ă  plusieurs composantes des changements environnementaux (qualitĂ© de l’hĂŽte, radiation ultraviolette, tempĂ©rature, invasion biologique). PremiĂšrement, j’ai comparĂ© la rĂ©ponse comportementale et de traits d’histoire de vie Ă  la variation de taille corporelle chez le parasitoĂŻde Telenomus podisi Ashmead (Hymenoptera : Platygastridae), dĂ©montrant que les normes de rĂ©action des comportements Ă©taient plus souvent positives que celles des traits d’histoires de vie. Ensuite, j’ai dĂ©montrĂ© que la punaise prĂ©datrice Podisus maculiventris Say (Hemiptera : Pentatomidae) peut contrĂŽler la couleur de ses Ɠufs, et que la pigmentation des Ɠufs protĂšge les embryons du rayonnement ultraviolet; une composante d’une stratĂ©gie complexe de ponte qui a Ă©voluĂ©e en rĂ©ponse Ă  une multitude de facteurs environnementaux. Puis, j’ai testĂ© comment le stress thermique affectait la dynamique de la mĂ©moire du parasitoĂŻde Trissolcus basalis (Wollaston) (Hymenoptera : Platygastridae) lors de l’apprentissage de la fiabilitĂ© des traces chimiques laissĂ©es par son hĂŽte. Ces expĂ©riences ont rĂ©vĂ©lĂ© que des tempĂ©ratures hautes et basses prĂ©venaient l’oubli, affectant ainsi l’allocation du temps passĂ© par les parasitoĂŻdes dans des agrĂ©gats d’hĂŽtes contenant des traces chimiques. J’ai aussi dĂ©veloppĂ© un cadre thĂ©orique gĂ©nĂ©ral pour classifier les effets de la tempĂ©rature sur l’ensemble des aspects comportementaux des ectothermes, distinguant les contraintes des adaptations. Finalement, j’ai testĂ© l’habiletĂ© d’un parasitoĂŻde indigĂšne (T. podisi) Ă  exploiter les Ɠufs d’un nouveau ravageur invasif en agriculture, Halyomorpha halys StĂ„l (Hemiptera : Pentatomidae). Les rĂ©sultats ont montrĂ© que T. podisi attaque les Ɠufs de H. halys, mais qu’il ne peut s’y dĂ©velopper, indiquant que le ravageur invasif s’avĂšre un « piĂšge Ă©volutif » pour ce parasitoĂŻde. Cela pourrait indirectement bĂ©nĂ©ficier aux espĂšces indigĂšnes de punaises en agissant comme un puits Ă©cologique de ressources (Ɠufs) et de temps pour le parasitoĂŻde. Ces rĂ©sultats ont des implications importantes sur la rĂ©ponse des insectes, incluant ceux impliquĂ©s dans les programmes de lutte biologique, face aux changements environnementaux.The environment shapes the physiology, morphology, and behaviour of organisms through complex, multidimensional ecological and evolutionary processes. The reproductive success of individual animals is determined by how well their phenotype is suited to an environment that is constantly changing over single and multi-generational time scales. At the same time, phenotypes are shaped by the environment, which triggers adaptive modifications of animal reproductive strategies while also imposing important constraints. In this thesis, using stink bugs and their parasitoids as model organisms, I considered how several types of plasticity can interact to influence biological fitness, and how plasticity in reproductive strategies responds to several important components of environmental change (host quality, ultraviolet radiation, temperature, biological invasions). Firstly, I compared the response of behavioural and life history traits to body size variation in the parasitoid Telenomus podisi Ashmead (Hymenoptera: Platygastridae), finding that reaction norms of behavioural traits more often had positive slopes than life history traits. Next, I found that the predatory stink bug Podisus maculiventris Say (Hemiptera: Pentatomidae) can selectively control the colouration of its eggs. Egg pigmentation in this species protects embryos against ultraviolet radiation as part of a complex oviposition strategy that evolved in response to a suite of environmental factors. Then, I tested how thermal stress affects the memory dynamics of the parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) learning the reliability of chemical traces left by its host. These experiments revealed that both high and low stressful temperatures prevented forgetting, affecting the time allocation of parasitoids on patches of host chemical traces. I also developed a general framework to classify temperature’s effects on all aspects of ectotherm behaviour, distinguishing constraints from adaptive behavioural adjustments. Finally, I tested the ability of an indigenous parasitoid (T. podisi) to attack the eggs of a new invasive pest of agriculture, Halyomorpha halys StĂ„l (Hemiptera: Pentatomidae). The results showed that T. podisi attacks the eggs of H. halys but cannot develop, demonstrating that the invasive pest is an “evolutionary trap” for indigenous parasitoids, which could indirectly benefit native stink bug species by acting as an egg and time sink for the parasitoid. These findings have important implications for how insects, including those involved in biological control programs, respond to environmental change

    The Unicellular State as a Point Source in a Quantum Biological System.

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    A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins

    Crater lake cichlids individually specialize along the benthic-limnetic axis

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    A common pattern of adaptive diversification in freshwater fishes is the repeated evolution of elongated open water (limnetic) species and high-bodied shore (benthic) species from generalist ancestors. Studies on phenotype-diet correlations have suggested that population-wide individual specialization occurs at an early evolutionary and ecological stage of divergence and niche partitioning. This variable restricted niche use across individuals can provide the raw material for earliest stages of sympatric divergence. We investigated variation in morphology and diet as well as their correlations along the benthic-limnetic axis in an extremely young Midas cichlid species, Amphilophus tolteca, endemic to the Nicaraguan crater lake Asososca Managua. We found that A. tolteca varied continuously in ecologically relevant traits such as body shape and lower pharyngeal jaw morphology. The correlation of these phenotypes with niche suggested that individuals are specialized along the benthic-limnetic axis. No genetic differentiation within the crater lake was detected based on genotypes from 13 microsatellite loci. Overall, we found that individual specialization in this young crater lake species encompasses the limnetic- as well as the benthic macro-habitat. Yet there is no evidence for any diversification within the species, making this a candidate system for studying what might be the early stages preceding sympatric divergence
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