55 research outputs found

    Pere Alberch's developmental morphospaces and the evolution of cognition

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    In this article we argue for an extension of Pere Alberch's notion of developmental morphospace into the realm of cognition and introduce the notion of cognitive phenotype as a new tool for the evolutionary and developmental study of cognitive abilities

    Communication : where evolutionary linguistics went wrong

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    In this article we offer a detailed assessment of current approaches to the origins of language, with a special focus on their historical and theoretical underpinnings. It is a widely accepted view within evolutionary linguistics that an account of the emergence of human language necessarily involves paying special attention to its communicative function and its relation to other animal communication systems. Ever since Darwin, some variant of this view has constituted the mainstream version in evolutionary linguistics; however, it is our contention in this article that this approach is seriously flawed, and that "animal communication" does not constitute a natural kind on which a sound theoretical model can be built. As a consequence, we argue that this communicative perspective is better abandoned in favor of a structural/formal approach based on the notion of homology, and that some interesting and unexpected similarities may be found by applying this venerable comparative method founded in the 19th century by Richard Owen

    Shearwater Foraging in the Southern Ocean: The Roles of Prey Availability and Winds

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    Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. Conclusions/Significance The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem

    Factors controlling individual branch development during early growth of an experimental plantation of Eucalyptus pilularis in sub-tropical Australia

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    Diameter at base, orientation, and height up the stem of live branches on the lower 5 m of tree stems were measured several times over 2.5–5.7 years of age in an experimental plantation of blackbutt (Eucalyptus pilularis) in sub-tropical eastern Australia. Stocking density at planting varied over 816–1667 stems ha-1 and rectangularity of planting (ratio of distance between rows to distance between trees within rows) over 1–6. Tree stem diameters, heights and crown dimensions were also measured. The height above ground at which branches emerged from the stem was a primary factor determining their growth; the higher they were, the greater was their diameter and the more vertical their orientation. This was believed to reflect both a need for newer branches to grow larger than older branches, to support greater amounts of foliage as the crowns expanded towards full size, and for branches to be better oriented to seek sunlight as the crowns of surrounding trees also expanded. Secondary factors determining branch size were tree size and spacing between trees, factors that are likely to interact with each other. Larger trees tended to have larger branches, to support more leaf weight in larger crowns. The direction of emergence of branches from stems seemed little affected by tree or stand characteristics at these early stages of tree development. The results did not suggest any need to modify existing pruning regimes that have been developed for fast-growing eucalypt plantations in Australia
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