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Do key innovations unlock diversification?A case-study on the morphological and ecological impact of pharyngognathy in acanthomorph fishes

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Current Zoology 2020年第5期66卷 575-588页

作者： Olivier Larouche jennifer r.hodge Laura r.V.Alencar Benjamin Camper Danielle S.Adams Katerina Zapfe Sarah T.Friedman Peter C.Wainwright Samantha A.Price Department of Biological Sciences Clemson UniversityClemsonSC29634USA Department of Evolution&Ecology University of California DavisDavisCA95616USA

Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter *** studies have focused on the impact of key inno vations on speciation rates,but far less is known about how they influe nee phe notypic rates and patterns of ecomorphological *** use the repeated evolution of pharyngognathy within acanthomorph fishes,a commonly cited key innovation,as a case study to explore the predicti ons of key inn ovation ***,we in vestigate whether transiti ons to phary ngognathy led to shifts in the rate of phenotypic evolution,as well as shifts and/or expansion in the occupation of morphological and dietary space,using a dataset of 8 morphological traits measured across 3,853 species of *** the 6 evolutionarily independent pharyngognathous clades together,we found no evidence to support pharyngognathy as a key innovation;however,comparisons between individual pharyngognathous lineages and their sister clades did reveal some consistent *** morphospace,most pharyngognathous clades cluster in areas that correspond to deeper-bodied morphologies relative to their sister clades,whereas occupying greater areas in dietary space that reflects a more diversified diet Additi on ally,both Cichlidae and Labridae exhibited higher univariate rates of phenotypic evolution compared with their closest ***,few of these results were exceptional relative to our null *** results suggest that transitions to pharyngognathy may only be advantageous when combined with additional ecological or intrinsic factors,illustrating the importance of account!ng for lineage-specific effects when testing key innovation ***,the challenges we experienced formulating informative comparisons,despite the ideal evolutionary scenario of multiple independent evolutionary origins of pharyngognathous clades,illustrates the comple

关键词： Acanthomorpha comparative methods ecomorphological diversification evolutionary innovations phenotypic rates

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Minimal Sufficiency in rare Populations

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Journal of Mathematics and System Science 2012年第5期2卷 281-285页

作者： Mohammad Moradi jennifer A. Brown Miriam hodge Department of Science Razi University Kermanshah 67146 Iran Department of Mathematics and Statistics University of Canterbury Christchurch 8011 New Zealand

It is well understood that for conventional survey designs the set of unordered distinct units in a sample is a minimally sufficient statistic. This means that for inferential statistic of the sample, the value of the sampled units rather than the sample design is important. Sampling rare populations presents distinct challenges. Examples of rare populations are in biology with rare and endangered animals where there are only a few remaining individuals, or in social science, with the low incidence of people from an unusually high （or low） income group. Sampling rare populations tends to result in the case that many of the sample units do not contain information on the characteristic of interest （e.g., the rare animal, or people from the unusual income group）. For finite rare populations the set of unordered distinct rare-units in a sample is a minimally sufficient statistic. In an example case study of a rare buttercup, the properties of the minimal sufficient estimator are explored. We compare the efficiency of the estimator for the population total based on the minimally sufficient statistic, with the standard estimator for a range of sample sizes. The variance of the minimally sufficient estimator was always smaller than the variance of the sufficient estimator. For rare populations where non-rare units can be distinguished from rare units because they have the same fixed value, the minimal sufficient statistic is the rare units, if any, in the sample.

关键词： rare population finite population sufficiency minimal sufficiency.

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