25 research outputs found

    Rationalism in public Law

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    Rationalism is ‘the stylistic criterion of all respectable politics’. So lamented political philosopher Michael Oakeshott in a series of essays published in the 1940s and 1950s. Rationalism, for Oakeshott, is shorthand for a propensity to prioritise the universal over the local, the uniform over the particular and, ultimately, principle over practice. It culminates in the triumph of abstract principles over practical knowledge in a manner that erodes our ability to engage in political activity. Although Oakeshott’s critique was made with the practice and study of politics in mind, it has a wider relevance. For rationalism, as we see it, has become the dominant style in public law. We draw upon Oakeshott’s critique to elucidate the risks associated with rationalism in public law and call for a renewed engagement with practical knowledge in the study of the constitution

    Repeated Lake-Stream Divergence in Stickleback Life History within a Central European Lake Basin

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    Life history divergence between populations inhabiting ecologically distinct habitats might be a potent source of reproductive isolation, but has received little attention in the context of speciation. We here test for life history divergence between threespine stickleback inhabiting Lake Constance (Central Europe) and multiple tributary streams. Otolith analysis shows that lake fish generally reproduce at two years of age, while their conspecifics in all streams have shifted to a primarily annual life cycle. This divergence is paralleled by a striking and consistent reduction in body size and fecundity in stream fish relative to lake fish. Stomach content analysis suggests that life history divergence might reflect a genetic or plastic response to pelagic versus benthic foraging modes in the lake and the streams. Microsatellite and mitochondrial markers further reveal that life history shifts in the different streams have occurred independently following the colonization by Lake Constance stickleback, and indicate the presence of strong barriers to gene flow across at least some of the lake-stream habitat transitions. Given that body size is known to strongly influence stickleback mating behavior, these barriers might well be related to life history divergence

    Experimental evidence for rapid genomic adaptation to a new niche in an adaptive radiation

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    A substantial part of biodiversity is thought to have arisen from adaptive radiations in which one lineage rapidly diversified into multiple lineages specialized to many different niches. However, selection and drift reduce genetic variation during adaptation to new niches and may thus prevent or slow down further niche shifts. We tested whether rapid adaptation is still possible from a highly derived ecotype in the adaptive radiation of threespine stickleback on the Haida Gwaii archipelago, Western Canada. In a 19-year selection experiment, we let giant sticklebacks from a large blackwater lake evolve in a small clearwater pond without vertebrate predators. A total of 56 whole genomes from the experiment and 26 natural populations revealed that adaptive genomic change was rapid in many small genomic regions and encompassed 75% of the change between 12,000-year-old ecotypes. Genomic change was as fast as phenotypic change in defence and trophic morphology, and both were largely parallel between the short-term selection experiment and long-term natural adaptive radiation. Our results show that functionally relevant standing genetic variation can persist in derived radiation members, allowing adaptive radiations to unfold very rapidly
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