Morphological discontinuous variation and disparity in Lutzomyia (Tricholateralis) cruciata Coquillett (Diptera: Psychodidae) are not related to contrasting environmental factors in two biogeographical provinces. ZOOMORPHOLOGY 138: 335-348.
PDF: https://rdcu.be/bEmL5
doi: https://doi.org/10.1007/s00435-019-00450-8
Lutzomyia cruciata (Diptera: Phlebotominae) is an important Leishmania vector with wide distribution in America. However, geographical patterns of morphological variation of populations along its longitudinal and latitudinal distribution are still unknown. In this work, we quantified morphological variation and disparity in 243 specimens (females) from nine sample groups of Lu. cruciata from two biogeographical provinces in Mexico: Veracruzan Province (five groups) and Yucatan Peninsula Province (four groups). We registered two linear morphometric data of a reproductive structure (spermatheca) and one landmark configuration for wing shape. Our questions were if intraspecific morphological variation and disparity are related to contrasting environmental factors in these two provinces. First, our results from canonical variates analyses of the spermatheca and wing shape revealed more differences among groups of specimens within a biogeographic province than between. Second, our regression analyses revealed that morphometric variation is weakly related to 20 environmental variables considered for the two biogeographic provinces. Levels of morphological disparity in the spermatheca and wing shape within the two provinces are the same regardless of environmental homogeneity in the Yucatan Province or heterogeneity in the Veracruzan Province. These patterns of morphological variation and disparity weakly correlated with environmental variables suggest that intraspecific variation in Lu. cruciata is not clinal within a province. Subsequent investigations will be required to elucidate suspected correlations of local discontinuous phenotypes with genetic divergence within a biogeographical province.
Keywords
Geometric morphometrics Wing Spermatheca Phlebotominae Leishmania mexicana
Showing posts with label 2019. Show all posts
Showing posts with label 2019. Show all posts
Chollet-Villalpando JG., FJ. García-Rodríguez, E. De Luna y J. De La Cruz-Agüero. 2019
Geometric morphometrics for the analysis of character variation in size and shape of
the sulcus acusticus of sagittae otolith in species of Gerreidae (Teleostei: Perciformes). MARINE BIODIVERSITY.
DOI: 10.1007/s12526-019-00970-y
PDF: https://rdcu.be/bIxBZ
Abstract.
Sagittal otoliths are a useful structure to distinguish teleostean fishes. However, character variation in size and shape of the sulcus acusticus has not been tested among Gerreidae Günther, 1862 species. For the first time, this paper explores the size and shape variation in the sulcus acusticus using landmark data and geometric morphometric methods. Variation in the sulcus acusticus size, as estimated with centroid size, is not a useful feature to distinguish neither the five genera nor all species in this study. However, since analyses of variance followed by Tukey a posteriori tests detect differences among groups of species, it is possible that the size of the sulcus acusticus will still be useful as a phylogenetic character. As expected, the pattern of variation in the shape of the sulcus acusticus consists of well-defined character states exclusive of each of the 18 species of Gerreidae included. All comparisons in multivariate analyses of variance of semi-landmark configurations with a CVA were statistically significant, and the rates for correct posterior classifications were all above 79%. Discriminant axes allowed to locate variation in particular regions of the sulcus acusticus outline that contribute most to the distinction among genera. Results revealed species in the same genus share a particular shape in the ostium and posterior extension of the cauda. Variation in the shape of the sulcus acusticus is, therefore, a very useful character to identify species in Gerreidae.
Keywords Character states Landmark data Morphological variation Silver biddies.
DOI: 10.1007/s12526-019-00970-y
PDF: https://rdcu.be/bIxBZ
Abstract.
Sagittal otoliths are a useful structure to distinguish teleostean fishes. However, character variation in size and shape of the sulcus acusticus has not been tested among Gerreidae Günther, 1862 species. For the first time, this paper explores the size and shape variation in the sulcus acusticus using landmark data and geometric morphometric methods. Variation in the sulcus acusticus size, as estimated with centroid size, is not a useful feature to distinguish neither the five genera nor all species in this study. However, since analyses of variance followed by Tukey a posteriori tests detect differences among groups of species, it is possible that the size of the sulcus acusticus will still be useful as a phylogenetic character. As expected, the pattern of variation in the shape of the sulcus acusticus consists of well-defined character states exclusive of each of the 18 species of Gerreidae included. All comparisons in multivariate analyses of variance of semi-landmark configurations with a CVA were statistically significant, and the rates for correct posterior classifications were all above 79%. Discriminant axes allowed to locate variation in particular regions of the sulcus acusticus outline that contribute most to the distinction among genera. Results revealed species in the same genus share a particular shape in the ostium and posterior extension of the cauda. Variation in the shape of the sulcus acusticus is, therefore, a very useful character to identify species in Gerreidae.
Keywords Character states Landmark data Morphological variation Silver biddies.
Ancona J.J. , J. J. Ortiz-Díaz, E. de Luna, J. Tun-Garrido y R. C. Berrientos-Medina. 2019
Statistical analyses of morphological variation in the Gymnopodium floribundum
complex (Polygonaceae): definition of three subspecies. ACTA BOTÁNICA MEXICANA 126: e1517. DOI: 10.21829/abm126.2019.1517
Abstract:
Background and Aims: Morphological variability in Gymnopodium floribundum along its distribution area has been the source of taxonomic and nomenclatural inconsistencies, sometimes recognizing up to three species and two varieties. In this paper we present morphometric analyses of variation in 224 specimens of G. floribundum in order to determine the existence of morphological patterns that correspond to geographically structured phenotypic diversity.
Methods: The data matrix consisted of 224 specimens and 32 characters, 21 were quantitative and 11 qualitative. A dendrogram was estimated with UPGMA’s algorithm and the Gower´s coefficient. The 21 quantitative characters were subjected to principal components analysis. With the groups identified in the dendrogram, we performed a PERMANOVA using all quantitative characters. Canonical Variate Analyses of leaf shape and perianth segment shape of all specimens were executed.
Key results: The results of multivariate analyses suggest the existence of three phenetic groups, which mostly correspond to three geographic regions: Belize, the Pacific Coastal Plain and the Yucatán Peninsula. These groups are distinguished by the presence or absence of indument on leaf blade, ochrea and petiole, the distances between the floral fascicles, and the length and width of the external and internal segments of the perianth. Two of the geographic groups correspond to infraspecific taxa previously recognized by Standley and Steyermark. Our distances and shape morphometric analyses uncover a third group from the southern Pacific region which presents novel characters.
Conclusions: Based on these results we raise the rank of two varieties G. floribundum var. antigonoides and G. floribundum var. floribundum to subspecies, and propose to recognize a new third subspecies: Gymnopodium floribundum subsp. chiapensis.
Key words: geometric morphometrics, Gymnopodium floribundum subsp. antigonoides, Gymnopodium floribundum subsp. floribundum, landmarks, morphological variation.
Resumen
Antecedentes y Objetivos: La variabilidad morfológica en Gymnopodium floribundum a lo largo de su área de distribución ha sido la fuente de inconsistencias taxonómicas y nomenclaturales, a veces reconociendo hasta tres especies y dos variedades. En este trabajo se presentan análisis morfométricos de variación en 224 especímenes de G. floribundum para determinar la existencia de patrones morfológicos que correspondan a una diversidad fenotípica geográficamente estructurada.
Métodos: La matriz de datos consistió en 224 especímenes y 32 caracteres, 21 fueron cuantitativos y 11 cualitativos. El dendrograma obtenido se construyó usando el algoritmo UPGMA y el coeficiente de Gower. Los 21 caracteres cuantitativos se sometieron a un análisis de componentes principales. Con los grupos identificados en el dendograma se realizaron ánalisis PERMANOVA utilizando caracteres cuantitativos. Se hicieron Análisis de Variación Canónica de la forma de la hoja y de la forma del segmento del perianto con todos los especímenes.
Resultados clave: Los resultados de los análisis multivariados sugieren la existencia de tres grupos fenéticos que en su mayoría corresponden a tres regiones geográficas: Belice, Costa del Pacífico y Península de Yucatán. Estos grupos se distinguen por la presencia o ausencia de indumento en la lámina de la hoja, ócrea y pecíolo, las distancias entre los fascículos florales y la longitud y anchura de los segmentos externos e internos del perianto. Dos de los grupos geográficos corresponden a taxones infraespecíficos previamente reconocidos por Standley y Steyermark. Los análisis morfométricos efectuados de distancias y formas descubren un tercer grupo de la región del Pacífico sur que presenta caracteres novedosos.
Conclusiones: Con base en estos resultados se eleva el rango de las variedades G. floribundum var. antigonoides y G. floribundum var. floribundum a subespecies, y se propone reconocer una nueva tercera subespecie: Gymnopodium floribundum subsp. chiapensis.
Palabras clave Gymnopodium floribundum subsp. antigonoides; Gymnopodium floribundum subsp. floribundum; landmark; morfometría geométrica; variación morfológica
Abstract:
Background and Aims: Morphological variability in Gymnopodium floribundum along its distribution area has been the source of taxonomic and nomenclatural inconsistencies, sometimes recognizing up to three species and two varieties. In this paper we present morphometric analyses of variation in 224 specimens of G. floribundum in order to determine the existence of morphological patterns that correspond to geographically structured phenotypic diversity.
Methods: The data matrix consisted of 224 specimens and 32 characters, 21 were quantitative and 11 qualitative. A dendrogram was estimated with UPGMA’s algorithm and the Gower´s coefficient. The 21 quantitative characters were subjected to principal components analysis. With the groups identified in the dendrogram, we performed a PERMANOVA using all quantitative characters. Canonical Variate Analyses of leaf shape and perianth segment shape of all specimens were executed.
Key results: The results of multivariate analyses suggest the existence of three phenetic groups, which mostly correspond to three geographic regions: Belize, the Pacific Coastal Plain and the Yucatán Peninsula. These groups are distinguished by the presence or absence of indument on leaf blade, ochrea and petiole, the distances between the floral fascicles, and the length and width of the external and internal segments of the perianth. Two of the geographic groups correspond to infraspecific taxa previously recognized by Standley and Steyermark. Our distances and shape morphometric analyses uncover a third group from the southern Pacific region which presents novel characters.
Conclusions: Based on these results we raise the rank of two varieties G. floribundum var. antigonoides and G. floribundum var. floribundum to subspecies, and propose to recognize a new third subspecies: Gymnopodium floribundum subsp. chiapensis.
Key words: geometric morphometrics, Gymnopodium floribundum subsp. antigonoides, Gymnopodium floribundum subsp. floribundum, landmarks, morphological variation.
Resumen
Antecedentes y Objetivos: La variabilidad morfológica en Gymnopodium floribundum a lo largo de su área de distribución ha sido la fuente de inconsistencias taxonómicas y nomenclaturales, a veces reconociendo hasta tres especies y dos variedades. En este trabajo se presentan análisis morfométricos de variación en 224 especímenes de G. floribundum para determinar la existencia de patrones morfológicos que correspondan a una diversidad fenotípica geográficamente estructurada.
Métodos: La matriz de datos consistió en 224 especímenes y 32 caracteres, 21 fueron cuantitativos y 11 cualitativos. El dendrograma obtenido se construyó usando el algoritmo UPGMA y el coeficiente de Gower. Los 21 caracteres cuantitativos se sometieron a un análisis de componentes principales. Con los grupos identificados en el dendograma se realizaron ánalisis PERMANOVA utilizando caracteres cuantitativos. Se hicieron Análisis de Variación Canónica de la forma de la hoja y de la forma del segmento del perianto con todos los especímenes.
Resultados clave: Los resultados de los análisis multivariados sugieren la existencia de tres grupos fenéticos que en su mayoría corresponden a tres regiones geográficas: Belice, Costa del Pacífico y Península de Yucatán. Estos grupos se distinguen por la presencia o ausencia de indumento en la lámina de la hoja, ócrea y pecíolo, las distancias entre los fascículos florales y la longitud y anchura de los segmentos externos e internos del perianto. Dos de los grupos geográficos corresponden a taxones infraespecíficos previamente reconocidos por Standley y Steyermark. Los análisis morfométricos efectuados de distancias y formas descubren un tercer grupo de la región del Pacífico sur que presenta caracteres novedosos.
Conclusiones: Con base en estos resultados se eleva el rango de las variedades G. floribundum var. antigonoides y G. floribundum var. floribundum a subespecies, y se propone reconocer una nueva tercera subespecie: Gymnopodium floribundum subsp. chiapensis.
Palabras clave Gymnopodium floribundum subsp. antigonoides; Gymnopodium floribundum subsp. floribundum; landmark; morfometría geométrica; variación morfológica
Solis-Zurita C., E. De Luna y D. González. 2019
Phylogenetic relationships in the Sceloporus variabilis (Squamata: Phrynosomatidae) complex based on three molecular markers, continuous characters, and geometric morphometric data. ZOOLOGICA SCRIPTA 48:419–439. DOI: 10.1111/zsc.12349
Abstract
The monophyly of the Sceloporus variabilis group is well established with five species and two species complexes, but phylogenetic relationships within species complexes are still uncertain. We studied 278 specimens in 20 terminals to sample all taxa in the “variabilis group,” including three subspecies in the “variabilis complex,” and two outgroups (Sceloporus grammicus and Sceloporus megalepidurus). We assembled an extensive morphological data set with discrete and continuous characters (distances and scale counts), including geometric morphometric data (landmark coordinates of three shapes), and a three‐marker molecular data set as well (ND4, 12S and RAG1). We conducted parsimony and Bayesian phylogenetic inferences on these data, including several partitioning and weighting schemes. We suggest elevating three subspecies to full species status. Therefore, we recommend recognition of nine species in the “variabilis group.” First, S. variabilis is sister to Sceloporus teapensis. In turn, Sceloporus cozumelae is sister to Sceloporus olloporus. These four species are a monophyletic group, which is sister to Sceloporus smithi. Finally, Sceloporus marmoratus is sister of the clade of five species. The other species in the “variabilis group” (Sceloporus chrysostictus, Sceloporus couchii and Sceloporus parvus) are a paraphyletic grade at the base of the tree. Our analyses reject the existence of the “variabilis complex.” We conducted a parsimony‐based ancestral reconstruction on body size (snout–vent length), femoral pores and dorsal scales and related morphological changes to geographic distribution of the species. Our phylogenetic hypothesis will allow best designs of comparative studies with species in the “variabilis group,” one of the earliest divergent lineages in the genus.
KEYWORDS geometric morphometrics, homology, phylogenetic morphometrics, Sceloporus, species complex
Abstract
The monophyly of the Sceloporus variabilis group is well established with five species and two species complexes, but phylogenetic relationships within species complexes are still uncertain. We studied 278 specimens in 20 terminals to sample all taxa in the “variabilis group,” including three subspecies in the “variabilis complex,” and two outgroups (Sceloporus grammicus and Sceloporus megalepidurus). We assembled an extensive morphological data set with discrete and continuous characters (distances and scale counts), including geometric morphometric data (landmark coordinates of three shapes), and a three‐marker molecular data set as well (ND4, 12S and RAG1). We conducted parsimony and Bayesian phylogenetic inferences on these data, including several partitioning and weighting schemes. We suggest elevating three subspecies to full species status. Therefore, we recommend recognition of nine species in the “variabilis group.” First, S. variabilis is sister to Sceloporus teapensis. In turn, Sceloporus cozumelae is sister to Sceloporus olloporus. These four species are a monophyletic group, which is sister to Sceloporus smithi. Finally, Sceloporus marmoratus is sister of the clade of five species. The other species in the “variabilis group” (Sceloporus chrysostictus, Sceloporus couchii and Sceloporus parvus) are a paraphyletic grade at the base of the tree. Our analyses reject the existence of the “variabilis complex.” We conducted a parsimony‐based ancestral reconstruction on body size (snout–vent length), femoral pores and dorsal scales and related morphological changes to geographic distribution of the species. Our phylogenetic hypothesis will allow best designs of comparative studies with species in the “variabilis group,” one of the earliest divergent lineages in the genus.
KEYWORDS geometric morphometrics, homology, phylogenetic morphometrics, Sceloporus, species complex
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