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Still slow, but even steadier: an update on the evolution of turtle cranial disparity interpolating shapes along branches.

ABSTRACT: In a previous study, we estimated the cranial disparity of turtles (Testudinata) through time using geometric morphometric data from both terminal taxa and hypothetical ancestors to compensate for temporal gaps in the fossil record. While this method yielded reasonable results for the Mesozoic and the early Cenozoic, we found a large drop in cranial disparity for the Miocene, for which we found no correlation with known environmental changes or extinction events. Instead, we speculated that the Miocene dip was a result of poor sampling of fossils or ancestors in this time bin. To countervail this problem, we here updated our original dataset and interpolated changes of shape along the branch lengths and compared them with the previous data. We furthermore explored the impact of topological and temporal uncertainty, demonstrating that the Miocene dip, indeed, is a sampling artefact. All remaining conclusions of the previous study could be more or less supported, nevertheless, including an apparent correlation with global biogeographic events, a minor correlation between cranial disparity and global temperature, and resilience across the K/T extinction event.

SUBMITTER: Foth C

PROVIDER: S-EPMC5717657 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Still slow, but even steadier: an update on the evolution of turtle cranial disparity interpolating shapes along branches.

Foth Christian C Ascarrunz Eduardo E Joyce Walter G WG

Royal Society open science 20171129 11

In a previous study, we estimated the cranial disparity of turtles (Testudinata) through time using geometric morphometric data from both terminal taxa and hypothetical ancestors to compensate for temporal gaps in the fossil record. While this method yielded reasonable results for the Mesozoic and the early Cenozoic, we found a large drop in cranial disparity for the Miocene, for which we found no correlation with known environmental changes or extinction events. Instead, we speculated that the ...[more]

PMID: 29291083

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Project description:BackgroundThe socioeconomic inequalities in child health continue to widen despite improved economy.ObjectiveTo investigate the correlation between socio-economic factors and health risk behaviors and psychosocial well-being of children in Hong Kong.HypothesisThe null hypothesis is that for this particular developed region, there exists little or no correlation between social-economic factors and health risk behaviors and psychosocial well-being of children.DesignCross sectional territory wide survey.ParticipantsCaregivers of 7,000 children in kindergartens in Hong Kong.Measuring toolsYouth Risk Behavior Surveillance questionnaire, health-related knowledge and hygienic practice questionnaire, and Children Behavior Checklist (CBCL).ResultsChildren were less likely to have somatic complaints and anxiety/depression as reflected by CBCL scores coming from families of higher income, not being recipients of social assistance, with fathers in employment, and with higher parental education. Children with only mother or father as caretakers had lower odds ratios (ORs) 0.71 (95% CI 0.58-0.89) and 0.53 (95% CI 0.33-0.84) respectively to have the habit of eating breakfast, whilst parental education at post-secondary level and higher family income had higher ORs 1.91 (95% CI 1.31-2.78), and 1.63 (95% CI 1.11-2.39). Fathers unemployed, relatives as main caretakers and living in districts with low median household inome incurred higher ORs, as 1.46 (95% CI 1.10-1.94),1.52 (95% CI 1.27-1.83) and 1.17 (95% CI 1.02-1.34) respectively, of watching television over two hours daily, whilst children with parental education at secondary level or above incurred lower OR 0.33 (95% CI 0.24-0.45). Children with parental education at post-secondary level and higher family income had lower ORs of 0.32 (95% CI 0.48-0.97) and 0.52 (95% CI 0.34-0.79) respectively, with regard to exposing to passive smoking, and reversed for those living in districts with lower median household income, lower family income and recipient of CSSA with ORs 1.24 (95% CI 1.06-1.44) and 1.6 (95% CI 1.09-2.37) respectively.ConclusionNull hypothesis was not supported. A strong gradient was still found to exist among different socio-economic groups for various health-related behaviors in developed society like Hong Kong.

Project description:BackgroundAlthough variation provides the raw material for natural selection and evolution, few empirical data exist about the factors controlling morphological variation. Because developmental constraints on variation are expected to act by influencing trait correlations, studies of modularity offer promising approaches that quantify and summarize patterns of trait relationships. Modules, highly-correlated and semi-autonomous sets of traits, are observed at many levels of biological organization, from genes to colonies. The evolutionary significance of modularity is considerable, with potential effects including constraining the variation of individual traits, circumventing pleiotropy and canalization, and facilitating the transformation of functional structures. Despite these important consequences, there has been little empirical study of how modularity influences morphological evolution on a macroevolutionary scale. Here, we conduct the first morphometric analysis of modularity and disparity in two clades of placental mammals, Primates and Carnivora, and test if trait integration within modules constrains or facilitates morphological evolution.Principal findingsWe used both randomization methods and direct comparisons of landmark variance to compare disparity in the six cranial modules identified in previous studies. The cranial base, a highly-integrated module, showed significantly low disparity in Primates and low landmark variance in both Primates and Carnivora. The vault, zygomatic-pterygoid and orbit modules, characterized by low trait integration, displayed significantly high disparity within Carnivora. 14 of 24 results from analyses of disparity show no significant relationship between module integration and morphological disparity. Of the ten significant or marginally significant results, eight support the hypothesis that integration within modules constrains morphological evolution in the placental skull. Only the molar module, a highly-integrated and functionally important module, showed significantly high disparity in Carnivora, in support of the facilitation hypothesis.ConclusionsThis analysis of within-module disparity suggested that strong integration of traits had little influence on morphological evolution over large time scales. However, where significant results were found, the primary effect of strong integration of traits was to constrain morphological variation. Thus, within Primates and Carnivora, there was some support for the hypothesis that integration of traits within cranial modules limits morphological evolution, presumably by limiting the variation of individual traits.

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Still slow, but even steadier: an update on the evolution of turtle cranial disparity interpolating shapes along branches.

Publications

Still slow, but even steadier: an update on the evolution of turtle cranial disparity interpolating shapes along branches.

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