Trade and Security Among the Ruins

The collision of trade and security interests is taking place today in an increasingly fragmented landscape. Governments’ conceptions of their own vital interests are undergoing a rapid transformation as the concept of “national security” expands to encompass issues such as national industrial policy, cybersecurity, and responses to climate change and pandemic disease. At the same time, the system for settling trade disputes is being pulled apart by competing tendencies toward legalism and deformalization. Last year, a landmark decision suggested that international adjudicators could oversee this clash between security and trade, deciding which security interests can override trade rules and which ones cannot. Then the collapse of the WTO Appellate Body threw into doubt the future of a legalized trade regime, suggesting a partial return to a system driven by politics. I argue that this fragmented landscape provides an opportunity to experiment with different ways of resolving the clash between trade and security. After introducing the expansion of state security interests with reference to recent policy developments, I identify three emerging models for reconciling expanded security interests with trade obligations: structured politics, trade legalism, and judicial managerialism. Each of these models brings tradeoffs in terms of oversight and flexibility, and each is associated with an ideal institutional setting. Rather than attempting to vindicate one model for all settings and all purposes, we should embrace plurality, especially at a moment where the relationship between trade and security appears to be undergoing a historic transformation

Analysis of planetary flyby using the Heliogyro solar sailer

Mission analysis for application of Heliogyro solar sailer concept to Jupiter flyb

Sea surface temperature contributes to marine crocodylomorph evolution

During the Mesozoic and Cenozoic, four distinct crocodylomorph lineages colonized the marine environment. They were conspicuously absent from high latitudes, which in the Mesozoic were occupied by warm-blooded ichthyosaurs and plesiosaurs. Despite a relatively well-constrained stratigraphic distribution, the varying diversities of marine crocodylomorphs are poorly understood, because their extinctions neither coincided with any major biological crises nor with the advent of potential competitors. Here we test the potential link between their evolutionary history in terms of taxic diversity and two abiotic factors, sea level variations and sea surface temperatures (SST). Excluding Metriorhynchoidea, which may have had a peculiar ecology, significant correlations obtained between generic diversity and estimated Tethyan SST suggest that water temperature was a driver of marine crocodylomorph diversity. Being most probably ectothermic reptiles, these lineages colonized the marine realm and diversified during warm periods, then declined or became extinct during cold intervals

The fossil record of early tetrapods: worker effort and the end-Permian mass extinction

It is important to understand the quality of the fossil record of early tetrapods (Tetrapoda, minus Lissamphibia and Amniota) because of their key role in the transition of vertebrates from water to land, their dominance of terrestrial faunas for over 100 million years of the late Palaeozoic and earlyMesozoic, and their variable fates during the end−Permian mass extinction. The first description of an early tetrapod dates back to 1824, and since then discoveries have occurred at a rather irregular pace, with peaks and troughs corresponding to some of the vicissitudes of human history through the past two centuries. As expected, the record is dominated by the well−sampled sedimentary basins of Europe and North America, but finds from other continents are increasing rapidly. Comparisons of snapshots of knowledge in 1900, 1950, and 2000 show that discovery of new species has changed the shape of the species−level diversification curve, contrary to earlier studies of family−level taxa. There is, however, little evidence that taxon counts relate to research effort (as counted by numbers of publications), and there are no biasing effects associated with differential study of different time intervals through the late Palaeozoic and Mesozoic. In fact, levels of effort are apparently not related to geological time, with no evidence that workers have spent more time on more recent parts of the record. In particular, the end−Permian mass extinction was investigated to determine whether diversity changes through that interval might reflect worker effort: it turns out that most records of early tetrapod taxa (when corrected for duration of geological series) occur in the Lower Triassic

Origins of Biodiversity

Biodiversity today is huge, and it has a long history. Identifying rules for the heterogeneity of modern biodiversity-the high to low species richness of different clades-has been hard. There are measurable biodiversity differences between land and sea and between the tropics and temperate-polar regions. Some analyses suggest that the net age of a clade can determine its extinction risk, but this is equivocal. New work shows that, through geological time, clades pass through different diversification regimes, and those regimes constrain the balance of tree size and the nature of branching events