Body size variability and water balance: A comparison between mainland and island populations ofMastomys huberti (Rodentia: Muridae) in Senegal

1995 ◽  
Vol 51 (4) ◽  
pp. 402-410 ◽  
Author(s):  
G. Ganem ◽  
L. Granjon ◽  
K. Ba ◽  
J. -M. Duplantier
Keyword(s):  
Body Size ◽  
Water Balance ◽  
Island Populations ◽  
Size Variability

scholarly journals The evolution of body size in termites

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Thomas Bourguignon
Keyword(s):  
Body Size ◽  
Size Reduction ◽  
Head Width ◽  
Termite Species ◽  
Fossil Species ◽  
Modern Species ◽  
Size Evolution ◽  
Phylogenetic Framework ◽  
Size Variability ◽  
Width Measurements

Termites are social cockroaches. Because non-termite cockroaches are larger than basal termite lineages, which themselves include large termite species, it has been proposed that termites experienced a unidirectional body size reduction since they evolved eusociality. However, the validity of this hypothesis remains untested in a phylogenetic framework. Here, we reconstructed termite body size evolution using head width measurements of 1638 modern and fossil termite species. We found that the unidirectional body size reduction model was only supported by analyses excluding fossil species. Analyses including fossil species suggested that body size diversified along with speciation events and estimated that the size of the common ancestor of modern termites was comparable to that of modern species. Our analyses further revealed that body size variability among species, but not body size reduction, is associated with features attributed to advanced termite societies. Our results suggest that miniaturization took place at the origin of termites, while subsequent complexification of termite societies did not lead to further body size reduction.

Changing invaders: trends of gigantism in insular introduced rats

2018 ◽  
Vol 45 (3) ◽  
pp. 203-211 ◽  
Author(s):  
ALEXANDRA A.E. VAN DER GEER
Keyword(s):  
Body Size ◽  
Solomon Islands ◽  
Mammalian Species ◽  
Island Rule ◽  
Island Populations ◽  
Island Group ◽  
Body Sizes ◽  
History Of ◽  
Analyse Data ◽  
Insular Populations

SUMMARYThe degree and direction of morphological change in invasive species with a long history of introduction are insufficiently known for a larger scale than the archipelago or island group. Here, I analyse data for 105 island populations of Polynesian rats,Rattus exulans, covering the entirety of Oceania and Wallacea to test whether body size differs in insular populations and, if so, what biotic and abiotic features are correlated with it. All insular populations of this rat, except one, exhibit body sizes up to twice the size of their mainland conspecifics. Body size of insular populations is positively correlated with latitude, consistent with thermoregulatory predictions based on Bergmann's rule. Body size is negatively correlated with number of co-occurring mammalian species, confirming an ecological hypothesis of the island rule. The largest rats are found in the temperate zone of New Zealand, as well as on mammalian species-poor islands of Polynesia and the Solomon Islands. Carnivory in the form of predation on nesting seabird colonies seems to promote 1.4- to 1.9-fold body size increases.

scholarly journals The effect of insularity on avian growth rates and implications for insular body size evolution

2019 ◽  
Vol 286 (1894) ◽  
pp. 20181967 ◽  
Author(s):  
Erik M. Sandvig ◽  
Tim Coulson ◽  
Sonya M. Clegg
Keyword(s):  
Body Size ◽  
Growth Rates ◽  
Food Limitation ◽  
Bird Species ◽  
Island Populations ◽  
Bird Populations ◽  
Size Evolution ◽  
Two Factors ◽  
Island Syndrome

Island populations often differ in consistent ways from their mainland counterparts with respect to their ecology, behaviour, morphology, demography and life-history characteristics; a set of changes referred to as the ‘island syndrome’. To understand the ecological and evolutionary drivers of the island syndrome requires characterization of suites of interacting traits. While patterns in some types of traits, e.g. body size, are well characterized across a range of taxa, key gaps remain. Growth rate is one such trait, being an important determinant of both increases and decreases in body size, and can vary with changes in predation pressure and food limitation; two factors that are known to differ between mainland and island environments. Using a phylogenetic meta-analytic approach, we characterize differences in growth rates among mainland and island altricial bird populations, controlling for environmental factors. We found a trend towards slower growth on islands in small-bodied (less than 1 kg) bird species. This is consistent with the idea that the pattern of body size increases in small-bodied island colonists is associated with the evolution of slower growth combined with shifts in age and size at maturity in relaxed predation regimes.

scholarly journals A global analysis of cladoceran body size and its variation linking to habitat, distribution and taxonomy

2019 ◽  
Vol 187 (4) ◽  
pp. 1119-1130 ◽  
Author(s):  
Eric Zeus Rizo ◽  
Shaolin Xu ◽  
Quehui Tang ◽  
Rey Donne S Papa ◽  
Henri J Dumont ◽  
...  
Keyword(s):  
Body Size ◽  
Large Scale ◽  
Global Analysis ◽  
Functional Trait ◽  
Categorical Variables ◽  
Extensive Literature ◽  
Frequency Distributions ◽  
Size Frequency ◽  
Size Variability ◽  
Taxonomic Affiliation

Abstract Body size is a functional trait that influences the overall biology and ecology of an organism. Studying the shape of size–frequency distributions and size variability within different scales, approximates the influence of large-scale ecological and evolutionary processes on a species. In this study we examine the patterns of distribution and variability of body size among freshwater Cladocera across different taxonomic levels, geographic distribution and habitat association. Using extensive literature data, we show the global distribution of body size in freshwater Cladocera. Hierarchical models were used to assess the effect of different categorical variables on size variability. Our results show that almost all size–frequency distributions were skewed right in all categories. The hierarchical model showed that taxonomic affiliation contributes the most to size variability in our dataset, suggesting that size might be a conserved trait. Large genera (≥1mm) have larger estimated variability compared to smaller genera. In general, our observations on size–frequency distributions and size variability show a brief insight in the varying advantages of adaptive body size in this group of organisms in both biology (physiology) and ecology (competition and co-existence). Thus, body size is a trait important to the survival and continuing evolution of Cladocera.

scholarly journals Variation in Morphology and Mating System Among Island Populations of GaláPagos Hawks

The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 428-438 ◽  
Author(s):  
Jennifer L. Bollmer ◽  
Tania Sanchez ◽  
Michelle Donaghy Cannon ◽  
Didier Sanchez ◽  
Brian Cannon ◽  
...  
Keyword(s):  
Body Size ◽  
Mating System ◽  
Sexual Size Dimorphism ◽  
Negative Relationship ◽  
Interspecific Variation ◽  
Size Dimorphism ◽  
Island Populations ◽  
Cooperative Polyandry ◽  
El Sistema ◽  
Los Grupos

Abstract Interspecific variation in sexual size dimorphism has commonly been attributed to variation in social mating system, with dimorphism increasing as intrasexual competition for mates increases. In birds, overall body size has also been found to correlate positively with size dimorphism. In this study, we describe variation in morphology and mating system across six populations of the endemic Galápagos Hawk (Buteo galapagoensis). Galápagos Hawks exhibit cooperative polyandry, a mating system in which long-term social groups contain a single female and multiple males. Comparisons among islands revealed significant differences in overall body size for both adults and immatures. Populations ranged from completely monogamous to completely polyandrous, with varying mean group sizes. Data did not support our prediction that sexual size dimorphism would increase with the degree of polyandry (number of males per group) or with body size; there was no correlation between mating system and sexual dimorphism. We did find a significant negative relationship between degree of polyandry and body size among islands, opposite of the pattern predicted. Variación en Morfología y Sistema de Apareamiento entre Poblaciones de Buteo galapagoensis Resumen. Variación interespecífica en dimorfismo sexual ha sido atribuída comúnmente a variaciones del sistema social de apareamiento, de tal manera que el dimorfismo aumenta conforme aumenta la competencia intrasexual por parejas reproductivas. También se ha encontrado que el tamaño corporal se correlaciona positivamente con el dimorfismo. En este estudio describimos la variación morfológica y el grado de poliandría de seis poblaciones de Buteo galapagoensis, una especie que exhibe un sistema de apareamiento denominado poliandría cooperativa. En este sistema los grupos de individuos reproductivos incluyen una sola hembra y múltiples machos. Se comprobó que existen diferencias significativas en el tamaño del cuerpo de adultos y juveniles entre islas. Las poblaciones muestreadas variaron entre monógamas y completamente poliándricas, y el tamaño promedio de los grupos fue variable. Los datos no apoyaron las predicciones establecidas inicialmente pues el grado de dimorfismo sexual no aumentó con el nivel de poliandría (número de machos por grupo) ni con el tamaño corporal, ni hubo una correlación entre el sistema de apareamiento y el dimorfismo sexual. La relación entre el tamaño corporal y el sistema de apareamiento fue contraria a la que se predijo: hubo una correlación negativa significativa entre el grado de poliandría y el tamaño corporal entre islas.

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