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Biology subjects

Grismer, L.

Publications and source records attributed to Grismer, L..

4 recordsLinked to original sources

Correcting for Body Size Variation in Morphometric Analysis

Using an allometric growth model to correct for body size variation has been known for many decades to be superior to several other widely used methods such as ratios, analysis of covariance, principal components analysis, and residual analysis. However, this technique remains relatively obscure and rarely applied. We optimize the implementation of this method through a newly developed and easy-to-use R package GroupStruct and use empirical datasets to test its relative efficacy compared to several commonly used methods. Our results demonstrate the superiority of the allometric method and highlights the negative impacts of applying improper body size correction methods.

zoology↗

Integrating spatial, phylogenetic, and threat assessment data from frogs and lizards to identify areas for conservation priorities in Peninsular Malaysia

Malaysia is recognized as a megadiverse country and biodiversity hotspot, which necessitates sufficient levels of habitat protection and effective conservation management. However, conservation planning in Malaysia has hitherto relied largely on species distribution data without taking into account the rich evolutionary history of taxa. This represents the first study that integrates spatial and evolutionary approaches to identify important centers of diversity, endemism, and bioregionalization that can be earmarked for conservation priorities in Peninsular Malaysia. Using georeferenced species occurrences, comprehensive phylogenies, and threat assessments of frogs and lizards, we employed a spatial phylogenetics framework that incorporates various diversity metrics including weighted endemism, phylogenetic diversity, phylogenetic endemism, and evolutionary distinctiveness and global endangerment. Ten areas of high conservation value were identified via the intersection of these metrics--northern Perlis, Langkawi Geopark, southern Bintang range, Cameron Highlands, Frasers Hill, Benom-Krau complex, Selangor-Genting complex, Endau-Rompin National Park, Seribuat Archipelago (Tioman and Pemanggil Islands), and southern Johor. Of these, Cameron Highlands requires the highest conservation priority based on severe environmental degradation, inadequately protected areas, and high numbers of endangered and evolutionary distinct species. Other areas, especially in the northwestern (states of Kedah and Penang) and northeastern regions (states of Kelantan) were not only identified as areas of high conservation value but also areas of biogeographic importance. Taken together, frogs and lizards demonstrate distinct east-west and north-south patterns of bioregionalization that are largely modulated by mountain ranges. Article Impact StatementThe first study to use a spatial phylogenetic approach to identify areas for conservation priorities in Malaysia

ecology↗

Species delimitation in the grey zone: introgression obfuscates phylogenetic inference and species boundaries in a cryptic frog complex (Ranidae: Pulchrana picturata)

As molecular methods continue to elucidate genetic structure at increasingly finer resolutions, delimiting species in the grey zone of the speciation continuum is becoming more relevant in biodiversity research, especially in under-studied biodiversity hotspots such as Southeast Asia where new species are being described at an unprecedented rate. Obvious species at both ends of the speciation continuum have mostly been described and attention is now turning towards the \"grey zone:\" an intermediate stage in which species criteria are in conflict and boundaries between populations and species are less clear. This study demonstrates that widely-used criteria (phylogenetic placement, genetic divergence, phylogeny- and distance-based species delimitation methods) can overestimate species diversity/boundaries when introgression is present. However, a comprehensive species delimitation framework that considers spatial and genetic population structure, introgression, and the use of species delimitation methods based on parameter estimation, can provide a more accurate characterization of species boundaries in this grey zone. We applied this approach to a group of Southeast Asian frogs from the Pulchrana picturata Complex that exhibits continuous morphological variation and high genetic divergences. Results showed that introgression was rampant among Bornean populations, which led to phylogenetic discordance and an overestimation of species. We suspect that our results do not form an isolated case; and that introgression among cryptic populations, occurring continuously across a wide geographic area (e.g., the topographically complex island of Borneo, and Earths major continents), may be more common than previously thought.

evolutionary biology↗

Exons, Introns, and UCEs Reveal Conflicting Phylogenomic Signals in a Rapid Radiation of Frogs (Ranidae: Hylarana)

The manuscript titled \"Exons, Introns, and UCEs Reveal Conflicting Phylogenomic Signals in a Rapid Radiation of Frogs (Ranidae: Hylarana)\" has been withdrawn from BioRxiv temporarily. The manuscript has been withdrawn because it utilizes a new protocol for data collection, which has yet not been published. Once the paper describing the new method becomes available for circulation, this manuscript will be resubmitted to BioRxiv. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

evolutionary biology↗