Climate change is increasing the temperatures of wild environments, but the impacts on evolutionary ecological processes, such as sexual selection, are still under-studied. In ectotermic tetrapods, male coloration is a pivotal trait in social contexts. During the reproductive season, males can enhance the dichromatic coloration of certain body regions. However, it is unknown how reproductive dichromatism might interact with the increasing temperatures that cause body temperatures to fall within the upper range of preferred temperatures. We hypothesize that sexual dichromatism could be dynamic, i.e. show changes, being reinforced during the reproductive period of the species. However, high temperatures associated with climate change could disrupt reproductive colour patterns by inducing plastic changes. We test this in the social lizard species Tropidurus spinulosus in a laboratory setting by applying three thermal treatments: one reproducing current thermal conditions and two simulating scenarios of climate change. Our results highlight that male coloration is enhanced during the reproductive season in key body regions for social displays. At the preferred temperature of the species, males could darken their ventral coloration; however, no such change was observed at high temperatures. Therefore, increasing temperatures could impact the capacity of males to adjust their coloration plastically during the reproductive season.
{"title":"Dynamic dichromatism and effects of high temperatures on male coloration plasticity in an ectotherm model","authors":"Nicola Rossi, Margarita Chiaraviglio, Gabriela Cardozo","doi":"10.1093/biolinnean/blae042","DOIUrl":"https://doi.org/10.1093/biolinnean/blae042","url":null,"abstract":"Climate change is increasing the temperatures of wild environments, but the impacts on evolutionary ecological processes, such as sexual selection, are still under-studied. In ectotermic tetrapods, male coloration is a pivotal trait in social contexts. During the reproductive season, males can enhance the dichromatic coloration of certain body regions. However, it is unknown how reproductive dichromatism might interact with the increasing temperatures that cause body temperatures to fall within the upper range of preferred temperatures. We hypothesize that sexual dichromatism could be dynamic, i.e. show changes, being reinforced during the reproductive period of the species. However, high temperatures associated with climate change could disrupt reproductive colour patterns by inducing plastic changes. We test this in the social lizard species Tropidurus spinulosus in a laboratory setting by applying three thermal treatments: one reproducing current thermal conditions and two simulating scenarios of climate change. Our results highlight that male coloration is enhanced during the reproductive season in key body regions for social displays. At the preferred temperature of the species, males could darken their ventral coloration; however, no such change was observed at high temperatures. Therefore, increasing temperatures could impact the capacity of males to adjust their coloration plastically during the reproductive season.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"67 E-8 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-18DOI: 10.1093/biolinnean/blae030
Jean Potvin, Alexander J Werth
Baleen plates of filter-feeding whales are longitudinally fibrous, separating where eroded medially into mats of fringes due to friction from water, prey, and the tongue. The fringes end up spreading-out, in other words suffusing, over the comb-like structure of the baleen assemblage. This study examined the relationships between mat morphology and the hydrodynamics it generates. Samples collected from nine rack locations on a bowhead whale (Balaena mysticetus) and fin whale (Balaenoptera physalus) were investigated with a new technique of mat porosity determination in a flume setting. Porosity was measured in the range of 5–20% and 8–37% in the bowhead and fin whale samples respectively. These were largest ventrally in both species, while remaining somewhat insensitive to the flume’s water speed. A new hydrodynamical model of the through-mat currents was used to estimate speeds of 0.15–3.0 cm/s and mat permeabilities of the order of 10−13 m2, depending on the applied pressure. Finally, and relative to samples collected near the entrance of the mouth, these trends were quantitatively similar in both species. With tongue- and flow-based erosion as the main mechanism for mat creation in all extant mysticetes, our analysis suggests baleen-generated filtration as having emerged early in their evolution.
{"title":"Suffused: baleen fringe mat porosity and hydrodynamics in balaenid and balaenopterid whales","authors":"Jean Potvin, Alexander J Werth","doi":"10.1093/biolinnean/blae030","DOIUrl":"https://doi.org/10.1093/biolinnean/blae030","url":null,"abstract":"Baleen plates of filter-feeding whales are longitudinally fibrous, separating where eroded medially into mats of fringes due to friction from water, prey, and the tongue. The fringes end up spreading-out, in other words suffusing, over the comb-like structure of the baleen assemblage. This study examined the relationships between mat morphology and the hydrodynamics it generates. Samples collected from nine rack locations on a bowhead whale (Balaena mysticetus) and fin whale (Balaenoptera physalus) were investigated with a new technique of mat porosity determination in a flume setting. Porosity was measured in the range of 5–20% and 8–37% in the bowhead and fin whale samples respectively. These were largest ventrally in both species, while remaining somewhat insensitive to the flume’s water speed. A new hydrodynamical model of the through-mat currents was used to estimate speeds of 0.15–3.0 cm/s and mat permeabilities of the order of 10−13 m2, depending on the applied pressure. Finally, and relative to samples collected near the entrance of the mouth, these trends were quantitatively similar in both species. With tongue- and flow-based erosion as the main mechanism for mat creation in all extant mysticetes, our analysis suggests baleen-generated filtration as having emerged early in their evolution.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"33 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-06DOI: 10.1093/biolinnean/blae039
Elisia Clara Menezes Araujo, Maria Cristina dos Santos-Costa, Adriano Oliveira Maciel
Basic ecological data for caecilians are relatively lacking. This study presents the first comprehensive ecological investigation of the Amazonian aquatic caecilian Potomotyphlus kaupii, utilizing a large sample size. We collected population data over a 14-month period, and also used data of museum specimens, both from Belém, State of Pará, Brazil. Our analysis focused on sex ratio, sexual size dimorphism (SSD), female fecundity, and ecological observations. No significant differences in adult sex ratio were found. SSD was found in some characters such as circumference at midbody and body mass with females being larger than males, while males had a wider and longer cloacal disc. We provide the first determination of the approximate size at which males diverge from females in the terminal portion of the body, demonstrating an allometric growth pattern of the cloacal region. Female size showed a positive correlation with the number of ovarian eggs, indicating an important reproductive strategy. Furthermore, a novel behaviour in P. kaupii was documented. We expand the understanding of Gymnophiona biology, in particular of a fully aquatic species, and provide support for future ecological and conservation research on caecilians.
{"title":"Life history of an evolutionary distinct aquatic caecilian amphibian (genus Potomotyphlus) in eastern Amazonia, Brazil","authors":"Elisia Clara Menezes Araujo, Maria Cristina dos Santos-Costa, Adriano Oliveira Maciel","doi":"10.1093/biolinnean/blae039","DOIUrl":"https://doi.org/10.1093/biolinnean/blae039","url":null,"abstract":"Basic ecological data for caecilians are relatively lacking. This study presents the first comprehensive ecological investigation of the Amazonian aquatic caecilian Potomotyphlus kaupii, utilizing a large sample size. We collected population data over a 14-month period, and also used data of museum specimens, both from Belém, State of Pará, Brazil. Our analysis focused on sex ratio, sexual size dimorphism (SSD), female fecundity, and ecological observations. No significant differences in adult sex ratio were found. SSD was found in some characters such as circumference at midbody and body mass with females being larger than males, while males had a wider and longer cloacal disc. We provide the first determination of the approximate size at which males diverge from females in the terminal portion of the body, demonstrating an allometric growth pattern of the cloacal region. Female size showed a positive correlation with the number of ovarian eggs, indicating an important reproductive strategy. Furthermore, a novel behaviour in P. kaupii was documented. We expand the understanding of Gymnophiona biology, in particular of a fully aquatic species, and provide support for future ecological and conservation research on caecilians.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"58 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-05DOI: 10.1093/biolinnean/blae004
Daniela Font, María Jimena Gómez Fernández, Facundo Robino, Bettina Aued, Soledad De Bustos, Agustín Paviolo, Verónica Quiroga, Patricia Mirol
The loss of biodiversity is an ongoing process and existing efforts to halt it are based on different conservation strategies. The ‘One Plan approach’ introduced by The International Union for Conservation of Nature proposes to consider all populations of a species under a unified management plan. In this work we follow this premise in order to unify in situ and ex situ management of one of the most critically endangered mammals in Argentina, the jaguar (Panthera onca). We assessed pedigrees of captive animals, finding that 44.93% of the reported relatedness was erroneous according to molecular data. Captive individuals formed a distinct genetic cluster. The three remaining locations for jaguars in Argentina constitute two genetic groups, the Atlantic Forest and the Chaco–Yungas clusters. Genetic variability is low compared with other populations of the species in the Americas and it is not significantly different between wild and captive populations in Argentina. These findings demonstrate that genetic studies aiming to include captive individuals into conservation management are very valuable, and should incorporate several parameters such as mean individual relatedness, individual inbreeding, rare and private alleles, and mitochondrial haplotypes. Finally, we discuss two ongoing ex situ management actions and postulate the need for genetic monitoring of the breeding and release of animals.
{"title":"The challenge of incorporating ex situ strategies for jaguar conservation","authors":"Daniela Font, María Jimena Gómez Fernández, Facundo Robino, Bettina Aued, Soledad De Bustos, Agustín Paviolo, Verónica Quiroga, Patricia Mirol","doi":"10.1093/biolinnean/blae004","DOIUrl":"https://doi.org/10.1093/biolinnean/blae004","url":null,"abstract":"The loss of biodiversity is an ongoing process and existing efforts to halt it are based on different conservation strategies. The ‘One Plan approach’ introduced by The International Union for Conservation of Nature proposes to consider all populations of a species under a unified management plan. In this work we follow this premise in order to unify in situ and ex situ management of one of the most critically endangered mammals in Argentina, the jaguar (Panthera onca). We assessed pedigrees of captive animals, finding that 44.93% of the reported relatedness was erroneous according to molecular data. Captive individuals formed a distinct genetic cluster. The three remaining locations for jaguars in Argentina constitute two genetic groups, the Atlantic Forest and the Chaco–Yungas clusters. Genetic variability is low compared with other populations of the species in the Americas and it is not significantly different between wild and captive populations in Argentina. These findings demonstrate that genetic studies aiming to include captive individuals into conservation management are very valuable, and should incorporate several parameters such as mean individual relatedness, individual inbreeding, rare and private alleles, and mitochondrial haplotypes. Finally, we discuss two ongoing ex situ management actions and postulate the need for genetic monitoring of the breeding and release of animals.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"124 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.1093/biolinnean/blae038
Eric G Prileson, Ryan A Martin
Divergent natural selection caused by spatial environmental variation can lead to local adaptation and evolutionary divergence between populations, even those within close proximity to one another. This, however, is only one possibility among other outcomes, such as the evolution of adaptive phenotypic plasticity or local maladaptation. Cities, as fragmented landscapes with high environmental variability across microgeographic scales, present an excellent venue to explore these possible outcomes. Here, we use common garden experiments to explore the potential for microgeographic divergence of physiological traits among populations of a collembolan, Orchesella villosa, living within the footprint of a single city. We assessed if intra-urban variation in the intensity of the heat island effect and soil salinity has led to evolutionary divergence in heat tolerance and salinity tolerance, respectively. While we found little variation in salinity tolerance among populations, there was evidence for both plasticity and evolutionary divergence among populations in response to variation in the urban heat island. Although the adaptive nature of these specific responses is not known, we suggest that cities, and human modified habitats in general, promote evolutionary divergence at small spatial scales by creating barriers to dispersal and imposing divergent selective environments within previously contiguous habitats.
{"title":"Evolution and plasticity of physiological traits in the collembolan Orchesella villosa at fine spatial scales within the city","authors":"Eric G Prileson, Ryan A Martin","doi":"10.1093/biolinnean/blae038","DOIUrl":"https://doi.org/10.1093/biolinnean/blae038","url":null,"abstract":"Divergent natural selection caused by spatial environmental variation can lead to local adaptation and evolutionary divergence between populations, even those within close proximity to one another. This, however, is only one possibility among other outcomes, such as the evolution of adaptive phenotypic plasticity or local maladaptation. Cities, as fragmented landscapes with high environmental variability across microgeographic scales, present an excellent venue to explore these possible outcomes. Here, we use common garden experiments to explore the potential for microgeographic divergence of physiological traits among populations of a collembolan, Orchesella villosa, living within the footprint of a single city. We assessed if intra-urban variation in the intensity of the heat island effect and soil salinity has led to evolutionary divergence in heat tolerance and salinity tolerance, respectively. While we found little variation in salinity tolerance among populations, there was evidence for both plasticity and evolutionary divergence among populations in response to variation in the urban heat island. Although the adaptive nature of these specific responses is not known, we suggest that cities, and human modified habitats in general, promote evolutionary divergence at small spatial scales by creating barriers to dispersal and imposing divergent selective environments within previously contiguous habitats.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"42 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.1093/biolinnean/blae037
Dylan W Maag, Yannick Z Francioli, Todd A Castoe, Gordon W Schuett, Rulon W Clark
Hybridization between species provides unique opportunities to understand evolutionary processes that are linked to reproductive isolation and, ultimately, speciation. However, the extrinsic factors that limit hybridization are poorly understood for most animal systems. Although the spatial ecology of individuals in natural habitats is fundamental to shaping reproductive success and survival, analyses of the spatial ecology of hybrids and their parental groups are rarely reported. Here, we used radiotelemetry to monitor wild rattlesnakes across an interspecific hybrid zone (Crotalus scutulatus and Crotalus viridis) and measured movement parameters and space use (utilization distributions) of individuals to evaluate the hypothesis that hybridization resulted in transgressive or atypical movement patterns. Unexpectedly, of the spatial metrics we investigated, we found that hybrids were very similar to parental individuals. Nonetheless, hybrids did show increased patchiness of core utilization distributions, but this result is likely to be driven by increased habitat patchiness in the hybrid zone. Overall, we did not find evidence for overt extrinsic barriers to hybridization associated with spatial ecology; thus, we suggest that the close evolutionary history between the two parental species and their ecological and behavioural similarities are likely to increase the probability of hybridization events in this unique region of New Mexico.
{"title":"The spatial ecology of Mojave rattlesnakes (Crotalus scutulatus), prairie rattlesnakes (Crotalus viridis), and their hybrids in southwestern New Mexico","authors":"Dylan W Maag, Yannick Z Francioli, Todd A Castoe, Gordon W Schuett, Rulon W Clark","doi":"10.1093/biolinnean/blae037","DOIUrl":"https://doi.org/10.1093/biolinnean/blae037","url":null,"abstract":"Hybridization between species provides unique opportunities to understand evolutionary processes that are linked to reproductive isolation and, ultimately, speciation. However, the extrinsic factors that limit hybridization are poorly understood for most animal systems. Although the spatial ecology of individuals in natural habitats is fundamental to shaping reproductive success and survival, analyses of the spatial ecology of hybrids and their parental groups are rarely reported. Here, we used radiotelemetry to monitor wild rattlesnakes across an interspecific hybrid zone (Crotalus scutulatus and Crotalus viridis) and measured movement parameters and space use (utilization distributions) of individuals to evaluate the hypothesis that hybridization resulted in transgressive or atypical movement patterns. Unexpectedly, of the spatial metrics we investigated, we found that hybrids were very similar to parental individuals. Nonetheless, hybrids did show increased patchiness of core utilization distributions, but this result is likely to be driven by increased habitat patchiness in the hybrid zone. Overall, we did not find evidence for overt extrinsic barriers to hybridization associated with spatial ecology; thus, we suggest that the close evolutionary history between the two parental species and their ecological and behavioural similarities are likely to increase the probability of hybridization events in this unique region of New Mexico.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"32 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-23DOI: 10.1093/biolinnean/blae031
Samira Brito Mendes, Fabiano Stefanello, Cleison Luís da Silva Costa, Amanda Cristiny da Silva Lima, Ana Priscila Medeiros Olímpio, Walna Micaelle de Morais Pires, Elmary da Costa Fraga, Maria Claudene Barros
Since morphological traits may overlap among species within a complex, the integration of morphological and mitochondrial data could provide crucial insights for distinguishing species, as observed in fruit-eating bats of the genus Artibeus. Therefore, the application of geometric morphometric (GM) techniques could yield more refined and robust analyses of inter- and intraspecific variations. In this study, we generated two datasets: one with molecular delimitation data based on the barcode region (COI) and the other with cranial size and shape data using GM methods. Our aims were to investigate variations between large and small species within the genus Artibeus, as well as to explore potential factors influencing such variations. The results from species delimitation revealed molecular operational taxonomic units (MOTUs) supporting the morphological identification. Analyses using GM techniques demonstrated significant inter- and intraspecific variations in cranial size and shape among Artibeus species. The combined outcomes suggest the absence of a significant phylogenetic signal influencing skull variation. This scenario indicates that potential historical ecological factors may have directly influenced the cranial morphology of these species, acting as significant selection forces in geographical space and generating intraspecific variations in Artibeus planirostris.
{"title":"Morphological and molecular data combined reveal inter- and intraspecific cranial shape variations in bats of Artibeus Leach, 1821 (Chiroptera: Phyllostomidae)","authors":"Samira Brito Mendes, Fabiano Stefanello, Cleison Luís da Silva Costa, Amanda Cristiny da Silva Lima, Ana Priscila Medeiros Olímpio, Walna Micaelle de Morais Pires, Elmary da Costa Fraga, Maria Claudene Barros","doi":"10.1093/biolinnean/blae031","DOIUrl":"https://doi.org/10.1093/biolinnean/blae031","url":null,"abstract":"Since morphological traits may overlap among species within a complex, the integration of morphological and mitochondrial data could provide crucial insights for distinguishing species, as observed in fruit-eating bats of the genus Artibeus. Therefore, the application of geometric morphometric (GM) techniques could yield more refined and robust analyses of inter- and intraspecific variations. In this study, we generated two datasets: one with molecular delimitation data based on the barcode region (COI) and the other with cranial size and shape data using GM methods. Our aims were to investigate variations between large and small species within the genus Artibeus, as well as to explore potential factors influencing such variations. The results from species delimitation revealed molecular operational taxonomic units (MOTUs) supporting the morphological identification. Analyses using GM techniques demonstrated significant inter- and intraspecific variations in cranial size and shape among Artibeus species. The combined outcomes suggest the absence of a significant phylogenetic signal influencing skull variation. This scenario indicates that potential historical ecological factors may have directly influenced the cranial morphology of these species, acting as significant selection forces in geographical space and generating intraspecific variations in Artibeus planirostris.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"142 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140200953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-22DOI: 10.1093/biolinnean/blae029
Omar Domínguez-Castanedo, Andrew W Thompson, Robert W Meredith, Andrew I Furness
An annual life cycle is characterized by short-lived adults that exploit seasonally productive but temporary habitats, paired with a hardy embryo stage that survives unfavourable environmental conditions, such as winter or the dry season. This life cycle is rare amongst vertebrates but has evolved independently several times in African and South American killifishes adapted to life in seasonally ephemeral aquatic pools. A single species of North American annual killifish, with a limited geographical distribution in Mexico, also exhibits this seasonal life cycle. This enigmatic species, Millerichthys robustus, is geographically separated from the nearest South American annual killifish species by >2000 km. Millerichthys robustus exhibits morphological features that have led to several competing phylogenetic hypotheses. To date, its phylogenetic relationships are unclear because no molecular data have been available. Here, we sequence the mitochondrial genome of Millerichthys robustus and generate a molecular phylogeny of killifishes that includes this species. Our results indicate that, rather than being most closely related to South American annual killifishes, this species is sister to two non-annual killifish species from Cuba (Rivulus cylindraceus and Rivulus berovidesi). Ancestral state reconstruction strongly supports an independent origin of an annual life cycle and embryonic diapause in Millerichthys robustus.
{"title":"An independent origin of an annual life cycle in a North American killifish species","authors":"Omar Domínguez-Castanedo, Andrew W Thompson, Robert W Meredith, Andrew I Furness","doi":"10.1093/biolinnean/blae029","DOIUrl":"https://doi.org/10.1093/biolinnean/blae029","url":null,"abstract":"An annual life cycle is characterized by short-lived adults that exploit seasonally productive but temporary habitats, paired with a hardy embryo stage that survives unfavourable environmental conditions, such as winter or the dry season. This life cycle is rare amongst vertebrates but has evolved independently several times in African and South American killifishes adapted to life in seasonally ephemeral aquatic pools. A single species of North American annual killifish, with a limited geographical distribution in Mexico, also exhibits this seasonal life cycle. This enigmatic species, Millerichthys robustus, is geographically separated from the nearest South American annual killifish species by >2000 km. Millerichthys robustus exhibits morphological features that have led to several competing phylogenetic hypotheses. To date, its phylogenetic relationships are unclear because no molecular data have been available. Here, we sequence the mitochondrial genome of Millerichthys robustus and generate a molecular phylogeny of killifishes that includes this species. Our results indicate that, rather than being most closely related to South American annual killifishes, this species is sister to two non-annual killifish species from Cuba (Rivulus cylindraceus and Rivulus berovidesi). Ancestral state reconstruction strongly supports an independent origin of an annual life cycle and embryonic diapause in Millerichthys robustus.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"4 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140200932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Species of the Thomomys subgenera of pocket gophers dig tunnels differentially; Thomomys are mainly claw-diggers while Megascapheus are tooth-diggers. Specific skull analyses could help in differentiating species in the bottae–umbrinus complex. This study revealed that Megascapheus shows similarity in cranium morphometry but that rostrum shape should show modifications associated with tooth-digging habits. We analysed cranium variation between Megascapheus species to identify interspecific variation. The variation in cranial morphometry within and between eight Megascapheus species was quantified through a two-dimensional geometric morphometry analysis based on 19 dorsal and 19 lateral reference points of 1172 specimens from different localities. Sample shape diversity and discrimination were analysed using principal component analysis (PCA) and canonical variable analysis (CVA). Sexual dimorphism tests were performed on cranium shape and size. A Student’s t-test was performed to explore differences between groups previously evaluated by CVA. PCA revealed considerable overlap across species in terms of view and sexes, with significant differences in Procrustes distances (shape) and centroid distances (size). The analyses showed that species in the subgenus Megascapheus have two main cranium morphotypes associated with the ecosystem that they inhabit. The analyses contribute to confirm the species level for T. fulvus and T. nigricans.
袋鼠Thomomys亚属的物种挖掘隧道的方式不同；Thomomys主要是爪掘式，而Megascapheus是齿掘式。具体的头骨分析有助于区分袋鼬亚属中的物种。这项研究发现，Megascapheus在头骨形态上表现出相似性，但喙的形状应表现出与掘齿习性相关的变化。我们分析了Megascapheus物种之间的颅骨变异，以确定种间变异。通过对来自不同地点的1172个标本的19个背侧参考点进行二维几何形态分析，量化了8个Megascapheus物种内部和物种之间头骨形态的变异。利用主成分分析（PCA）和典型变量分析（CVA）对样本形状的多样性和区分度进行了分析。对颅骨的形状和大小进行了性二型检验。采用学生 t 检验来探讨先前用 CVA 评估过的群体之间的差异。PCA 发现不同物种在视角和性别方面有相当大的重叠，但在 Procrustes 距离（形状）和中心距（大小）方面存在显著差异。分析表明，Megascapheus 亚属的物种有两种主要的头盖骨形态类型，这与其栖息的生态系统有关。这些分析有助于确认巨蜥和巨蜥的物种级别。
{"title":"Cranium morphology prevalence among digging habits in Thomomys species","authors":"Sergio Ticul Álvarez-Castañeda, Alina Gabriela Monroy-Gamboa","doi":"10.1093/biolinnean/blae033","DOIUrl":"https://doi.org/10.1093/biolinnean/blae033","url":null,"abstract":"Species of the Thomomys subgenera of pocket gophers dig tunnels differentially; Thomomys are mainly claw-diggers while Megascapheus are tooth-diggers. Specific skull analyses could help in differentiating species in the bottae–umbrinus complex. This study revealed that Megascapheus shows similarity in cranium morphometry but that rostrum shape should show modifications associated with tooth-digging habits. We analysed cranium variation between Megascapheus species to identify interspecific variation. The variation in cranial morphometry within and between eight Megascapheus species was quantified through a two-dimensional geometric morphometry analysis based on 19 dorsal and 19 lateral reference points of 1172 specimens from different localities. Sample shape diversity and discrimination were analysed using principal component analysis (PCA) and canonical variable analysis (CVA). Sexual dimorphism tests were performed on cranium shape and size. A Student’s t-test was performed to explore differences between groups previously evaluated by CVA. PCA revealed considerable overlap across species in terms of view and sexes, with significant differences in Procrustes distances (shape) and centroid distances (size). The analyses showed that species in the subgenus Megascapheus have two main cranium morphotypes associated with the ecosystem that they inhabit. The analyses contribute to confirm the species level for T. fulvus and T. nigricans.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"32 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140205589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-20DOI: 10.1093/biolinnean/blae027
Clarisa Marek Ortiz, Juan J Martínez, Ricardo Sahade, M Carla de Aranzamendi
Ecotypes constitute valuable markers for understanding the phenotypic responses influenced by evolutionary forces and environmental variations. Assessing the role of these processes in establishing and maintaining ecotype divergence is essential for anticipating evolutionary responses to future climate shifts. We studied the evolutionary dynamics of phenotypic population structure between Nacella concinna ecotypes through a morphometric and temporal analysis (2004–2021) in Antarctica. This approach enables the assessment of contemporary evolutionary dynamics in the presence of biotic and abiotic factors, facilitating the inference of interactions between the acting forces. Using generalized Procrustes analysis, ecotypes were successfully discriminated by their lateral shell traits consistently persisting over the analysed period. Multivariate linear and univariate mixed models revealed a significant temporal effect on shell phenotypic variation, surpassing the effect of inter-ecotype differences. However, according to phenotypic trajectory analysis, this temporal effect did not alter the direction of the phenotypic trajectory of ecotype shell shape, which evolved in parallel during the time series. Despite the environmental variation, the evidence of parallel evolution might indicate the incidence of natural selection in ecotype divergence rather than relying solely on phenotypic plasticity. This work enhances our understanding of ecotype temporal changes and microevolution, underscoring the importance of long-term phenotypic monitoring.
{"title":"Stability of parallel evolution in shell traits between the littoral and sublittoral ecotypes of the Antarctic limpet Nacella concinna along a 17-year time series","authors":"Clarisa Marek Ortiz, Juan J Martínez, Ricardo Sahade, M Carla de Aranzamendi","doi":"10.1093/biolinnean/blae027","DOIUrl":"https://doi.org/10.1093/biolinnean/blae027","url":null,"abstract":"Ecotypes constitute valuable markers for understanding the phenotypic responses influenced by evolutionary forces and environmental variations. Assessing the role of these processes in establishing and maintaining ecotype divergence is essential for anticipating evolutionary responses to future climate shifts. We studied the evolutionary dynamics of phenotypic population structure between Nacella concinna ecotypes through a morphometric and temporal analysis (2004–2021) in Antarctica. This approach enables the assessment of contemporary evolutionary dynamics in the presence of biotic and abiotic factors, facilitating the inference of interactions between the acting forces. Using generalized Procrustes analysis, ecotypes were successfully discriminated by their lateral shell traits consistently persisting over the analysed period. Multivariate linear and univariate mixed models revealed a significant temporal effect on shell phenotypic variation, surpassing the effect of inter-ecotype differences. However, according to phenotypic trajectory analysis, this temporal effect did not alter the direction of the phenotypic trajectory of ecotype shell shape, which evolved in parallel during the time series. Despite the environmental variation, the evidence of parallel evolution might indicate the incidence of natural selection in ecotype divergence rather than relying solely on phenotypic plasticity. This work enhances our understanding of ecotype temporal changes and microevolution, underscoring the importance of long-term phenotypic monitoring.","PeriodicalId":55373,"journal":{"name":"Biological Journal of the Linnean Society","volume":"1 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140201336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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