1,720,981 research outputs found
Genes, shells, and AI: Using computer vision to detect cryptic morphological divergence between genetically distinct populations
No full textMany species are composed of two or more genetically distinct clades, indicating ongoing or past evolutionary divergence. Often however, there are no obvious morphological differences between clades, making it difficult to accurately assess specific aspects of biodiversity or to enact targeted conservation efforts. New advancements in artificial intelligence tools can be used to categorise individuals into their respective genetic clades and to highlight their distinguishing morphological characters that would otherwise be hidden from human observers. Here, we applied computer vision and explainable artificial intelligence techniques to four limpet species that display well-defined phylogeographic breaks along the Baja California and California coasts. A fine-tuned convolutional network, trained and evaluated over 100 resampling iterations, classified individuals into their genetic clades with median F1-scores of up to 0.96. F1-score performance was markedly higher for true clade groups than the controlled mixed-groups, confirming the presence of features specific to the clades. Saliency maps consistently emphasised structures such as the keyhole in Fissurella volcano and the ridge tips in Lottia conus as distinguishing features, and subsequent shape analyses confirmed significant divergence between clades. These results demonstrate the power of computer vision and explainable artificial intelligence to expose otherwise cryptic morphological diversity and provide a scalable, reproducible workflow that can broaden the biodiversity toolkit and refine eco-evolutionary research across taxa
Data from: predator-induced defences under tropicalisation: a biogeographic approach
No full textAim: The biogeography of predator-induced defences is an understudied area of predator-prey dynamics. Range overlap with predators that induce the response and local demographics (e.g., prey abundances) are likely to be important factors for determining the biogeographic distribution of induced defences within species. However, with climate warming, range expanding warm-water predators are increasingly preying upon temperate species. This is a consequence of a wider phenomenon known as tropicalisation. We aim to determine: (i) if individuals of a temperate barnacle with induced defences ("bent morphs") are primarily present where they co-occur with range-expanding warm-water predators (muricid snails) and, (ii) if bent morphs are size-structured within populations. Location: North-eastern Pacific rocky intertidal zone (~26-40ºN) Taxon: Tetraclita rubescens (Nilsson-Cantell, 1931), Balanomorpha Methods: We use photo quadrats from sites across the range of T. rubescens to determine the biogeographic distribution of populations with bent morphs and to assess size-structure. We use a combination of field surveys, literature, and museum occurrences to assess range overlap between cool and warm-water predators of T. rubescens and their association with populations with bent morphs and abundance patterns of T. rubescens. Results: Bent morphs are commonly found within the equatorward portion of the species' range (where abundances are highest), in populations overlapping with range expanding warm-water predators. Bent morphs primarily occur within the smaller size classes. Main conclusions: To be partly resilient to the effects of tropicalisation, temperate prey must acclimatize/adapt to altered predator-prey dynamics. Predator-induced defences are one way to do this. We show that bent morphs within a temperate prey species (T. rubescens) are largely restricted to populations that overlap with large-bodied and range-expanding warm-water predators. This is evidence for the partial resilience of T. rubescens to tropicalisation and provides the rationale for further exploration of the eco-evolutionary consequences of tropicalisation in this study system and others.</span
Predator-induced defences under tropicalisation: a biogeographic approach
No full textAim: the biogeography of predator-induced defences is an understudied area of predator–prey dynamics. Range overlap with predators that induce the response and local demographics (e.g., prey abundances) are likely to be important factors for determining the biogeographic distribution of induced defences within species. However, with climate warming, range-expanding warm-water predators are increasingly preying upon temperate species. This is a consequence of a wider phenomenon known as tropicalisation. We aim to determine: (i) if individuals of a temperate barnacle with induced defences (‘bent morphs’) are primarily present where they co-occur with range-expanding warm-water predators (muricid snails) and, (ii) if bent morphs are size-structured within populations.Location: north-eastern Pacific rocky intertidal zone (~26–40° N).Taxon: Tetraclita rubescens (Nilsson-Cantell, 1931), Balanomorpha.Methods: we use photoquadrats from sites across the range of T. rubescens to determine the biogeographic distribution of populations with bent morphs and to assess size-structure. We use a combination of field surveys, literature, and museum occurrences to assess range overlap between cool and warm-water predators of T. rubescens and their association with populations with bent morphs and abundance patterns of T. rubescens.Results: bent morphs are commonly found within the equatorward portion of the species' range (where abundances are highest), in populations overlapping with range-expanding warm-water predators. Bent morphs primarily occur within the smaller size classes.Main conclusions: to be partly resilient to the effects of tropicalisation, temperate prey must acclimatise/adapt to altered predator–prey dynamics. Predator-induced defences are one way to do this. We show that bent morphs within a temperate prey species (T. rubescens) are largely restricted to populations that overlap with large-bodied and range-expanding warm-water predators. This is evidence for the partial resilience of T. rubescens to tropicalisation and provides the rationale for further exploration of the eco-evolutionary consequences of tropicalisation in this study system and others
GASTROPODS AND BIVALVES OF COMMERCIAL INTEREST FROM THE CONTINENTAL SHELF OF JALISCO AND COLIMA, MEXICO
No full textGastropods and bivalves of commercial interest from the continental shelf of Jalisco and Colima, México
No full textDinámica poblacional del erizo morado Strongylocentrotus purpuratus en el borde entre un manto de sargazo y un desierto de erizos en la Península de Baja California, México
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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