8,616 research outputs found

    Conference proceedings of the II Iberian Symposium on geometric morphometrics

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    Does geometric morphometrics provide congruent results with SNP data? The case of Iberian honey bee (Apis mellifera iberiensis)

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    While molecular markers are usually preferred to infer population structure, geometric morphometrics is a cheap method that has been widely applied to the wings of female honey bees to identify subspecies or lineages and can be used alternatively or complementarily to molecular markers. However, the power of geometric morphometrics to capture the signature of complex evolutionary processes has not been tested in honey bees. In this study, we applied geometric morphometrics, combined with geographical information, to the right forewings of female individuals from 711 colonies distributed along the Iberian Peninsula, which contains a complex population structure. The results were further compared with those obtained using 383 SNPs. Our data showed that geometric morphometrics provided a similar spatial structure of SNPs data (r=0.90). Our findings reinforce the power of spatially explicit wing geometric morphometrics data to capture the signature of complex evolutionary processes. Thus, this method could be used as a low-cost alternative for preliminary estimation of population structure.info:eu-repo/semantics/publishedVersio

    Asymmetry of Caddo Ceramics from the Washington Square Mound Site: An Exploratory Analysis

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    While pursuing a study of 3D geometric morphometrics for ceramic burial vessels that often articulate with the Native American Graves Protection and Repatriation Act (NAGPRA) from the ancestral Caddo region, there have been no shortage of potentially meaningful observations, one of which--rotational asymmetry in coil-built vessels--is discussed here. Using Geomagic Design X (reverse-engineering software) and Geomagic Control X (inspection software), metrics associated with rotational asymmetry were generated then analyzed. Results indicate variable asymmetry among the different vessel shapes (i.e., bottles, jars, etc.), which may augment and strengthen studies and discussion of vessel form. Future directions include the incorporation of directional and--possibly--fluctuating asymmetry measures for the widest vessel profiles. Preliminary results point toward substantive analytical gains that can be used to augment more traditional ceramic analyses as well as geometric morphometric studies of ceramic vessel shape

    Males resemble females. re-evaluating sexual dimorphism in protoceratops andrewsi (neoceratopsia, protoceratopsidae)

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    BACKGROUND: Protoceratops andrewsi (Neoceratopsia, Protoceratopsidae) is a well-known dinosaur from the Upper Cretaceous of Mongolia. Some previous workers hypothesized sexual dimorphism in the cranial shape of this taxon, using qualitative and quantitative observations. In particular, width and height of the frill as well as the development of a nasal horn have been hypothesized as potentially sexually dimorphic. METHODOLOGY/PRINCIPAL FINDINGS: Here, we reassess potential sexual dimorphism in skulls of Protoceratops andrewsi by applying two-dimensional geometric morphometrics to 29 skulls in lateral and dorsal views. Principal Component Analyses and nonparametric MANOVAs recover no clear separation between hypothetical "males" and "females" within the overall morphospace. Males and females thus possess similar overall cranial morphologies. No differences in size between "males" and "females" are recovered using nonparametric ANOVAs. CONCLUSIONS/SIGNIFICANCE: Sexual dimorphism within Protoceratops andrewsi is not strongly supported by our results, as previously proposed by several authors. Anatomical traits such as height and width of the frill, and skull size thus may not be sexually dimorphic. Based on PCA for a data set focusing on the rostrum and associated ANOVA results, nasal horn height is the only feature with potential dimorphism. As a whole, most purported dimorphic variation is probably primarily the result of ontogenetic cranial shape changes as well as intraspecific cranial variation independent of sex

    Advances in Geometric Morphometrics

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    Biometry traits and geometric morphometrics in sea bass (Dicentrarchus labrax) from different farming systems

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    The effect of the farming system on biometry traits and dressing out yield were inves- tigated in market-size European sea bass (Dicentrarchus labrax) cultured extensively or intensively in sea cages or land-based basins. Fish external appearences and shapes were studies with geometric morphometrics in order to assess the potential of combined methodologies in the assessment of finfish quality. Both standard biometry and geometric morphometrics were able to discriminate between sea bass farmed extensively from those cultured under intensive conditions. Geometric morphometrics has been shown to be a valuable tool for describing changes in shape features and could result a useful technique to be associated to biometry traits in the context of fish quality assessment

    Translational genetic modelling of 3D craniofacial dysmorphology: elaborating the facial phenotype of neurodevelopmental disorders through the prism of schizophrenia

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    Purpose of Review: In the context of human developmental conditions, we review the conceptualisation of schizophrenia as a neurodevelopmental disorder, the status of craniofacial dysmorphology as a clinically accessible index of brain dysmorphogenesis, the ability of genetically modified mouse models of craniofacial dysmorphology to inform on the underlying dysmorphogenic process and how geometric morphometric techniques in mutant mice can extend quantitative analysis. Recent Findings: Mutant mice with disruption of neuregulin-1, a gene associated meta-analytically with risk for schizophrenia, constitute proof-of-concept studies of murine facial dysmorphology in a manner analogous to clinical studies in schizophrenia. Geometric morphometric techniques informed on the topography of facial dysmorphology and identified asymmetry therein. Summary: Targeted disruption in mice of genes involved in individual components of developmental processes and analysis of resultant facial dysmorphology using geometric morphometrics can inform on mechanisms of dysmorphogenesis at levels of incisiveness not possible in human subjects
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