scholarly journals Sizing Up Swords: Correlated Evolution of Antlers and Tusks in Ungulates

2021 ◽  
Author(s):  
Nicole Lopez ◽  
Theodore Stankowich
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Visual Signal ◽  
Allometric Relationships ◽  
Energy Investment ◽  
Correlated Evolution ◽  
Skull Length ◽  
Body Sizes ◽  
Size Scales ◽  
Development And Evolution

Abstract Most sexual weapons in sexual combat and visual displays of dominance (e.g., antlers, horns) show positively allometry with body size for both growth during development and evolution across species, but allometry in species with more than one sexual weapon is unstudied. We examined the allometric relationships between body size and tusks (pure combat weapons) and/or antlers (both a visual signal and combat weapon) from forty-three artiodactyl species including the muntjaks (Muntiacinae), which uniquely have both antlers and tusks. We found that in Muntiacinae antler length scales positively allometrically with skull length, whereas tusk size scales isometrically suggesting greater energy investment in antlers as signals over tusks as combative weapons when both are present. Interspecifically, we found that species who possess only one weapon (either solely tusked or solely antlered) scaled positively allometrically with body mass, and the latter relationship levels off at larger body sizes. In our tusk analysis, when we included Muntiacinae species the positive allometric trend was not conserved resulting in an isometric relationship suggesting the possession of antlers negatively affect the energy investment in tusks as weapons. Overall, our findings show that species that possess dual weapons unproportionally invest energy in the development and maintenance of their multiple weapons.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

scholarly journals Weight-Related Selves and Their Relationship With Body Mass Index Among Young Individuals in Curaçao

2019 ◽  
Vol 45 (4) ◽  
pp. 306-334 ◽  
Author(s):  
Pieternel Dijkstra ◽  
Odette Van Brummen-Girigori ◽  
Dick P. H. Barelds
Keyword(s):  
Body Mass Index ◽  
Body Size ◽  
Secondary School ◽  
Body Dissatisfaction ◽  
Body Mass ◽  
Secondary School Students ◽  
The Body ◽  
School Students ◽  
Two Samples ◽  
Body Sizes

Based on the assumptions of self-discrepancy theory, the present study examined the degree of overweight, weight-related body images, and the relation between these images and body mass index (BMI) among two samples of young people from Curaçao (secondary school students, n = 176; undergraduate students, n = 205). In addition to BMI, participants reported their current, ideal, and most feared body sizes, the thinnest and largest body sizes still acceptable to them, and the body size they considered the healthiest by means of the Contour Drawing Rating Scale. We expected females to show a larger discrepancy between current and ideal body size than males (Hypothesis 1) and that this discrepancy (as an indicator of body dissatisfaction) would be related more strongly to BMI among females than among males (Hypothesis 2). Results yielded support for Hypothesis 1 among secondary school students only. Only in the undergraduate sample, BMI and body dissatisfaction were related, but equally so for males and females. Possible explanations are discussed as well as implications for weight management interventions.

A new, diminutive species ofCatopsalis(Mammalia, Multituberculata, Taeniolabidoidea) from the early Paleocene of southwestern Alberta, Canada

2018 ◽  
Vol 92 (5) ◽  
pp. 896-910
Author(s):  
Craig S. Scott ◽  
Anne Weil ◽  
Jessica M. Theodor
Keyword(s):  
New Species ◽  
Body Size ◽  
Body Mass ◽  
North American ◽  
Phylogenetic Position ◽  
Early Paleocene ◽  
Body Sizes ◽  
History Of ◽  
American Clade ◽  
A New Species

AbstractMultituberculates were among the most taxonomically diverse mammals of the early Paleocene, having survived the catastrophic Cretaceous-Paleogene mass extinction and radiating soon thereafter. Although their evolution during the early Paleocene saw the advent of increasingly specialized dentitions, multituberculates generally remained small, rarely exceeding body sizes greater than those of extant rabbits. A conspicuous exception is the Taeniolabidoidea, a primarily North American clade whose members include the largest multituberculates yet discovered. Taeniolabidoidea includes several genera, with one of these,Catopsalis, being speciose and geographically wide ranging. Until recently, the chronological succession ofCatopsalisappeared to document a trend of increasing body size. We report here on a new species ofCatopsalisfrom the early Paleocene of Alberta that violates this trend and suggests that the evolutionary history ofCatopsalisis considerably more complex.Catopsalis kakwanew species is not only the smallest species ofCatopsalis, but is the smallest taeniolabidoid so far discovered, with an estimated body mass between 400 g and 660 g. In contrast to previous studies, we used recently proposed regressions based on lower cheek tooth row length to estimate body masses for North American taeniolabidoids. Our results propose more modest body mass estimates, particularly for the largest taeniolabidoids. The occurrence ofC.kakwan. sp. in the late early Paleocene implies either a significant ghost lineage, or reversal of several characters, including body size, during the latter part of the early Paleocene; the more likely of these scenarios must await a better understanding of the phylogenetic position ofC.kakwan. sp.UUID:http://zoobank.org/66d85345-49b8-4a46-ba6e-a4d4369cb3e0urn:lsid:zoobank.org:pub:AF7A5659-9068-4F2F-A6EC-5522A2BBA4CB

Fossil horses from “Eohippus” (Hyracotherium) to Equus: scaling, Cope's Law, and the evolution of body size

Paleobiology ◽  
1986 ◽  
Vol 12 (4) ◽  
pp. 355-369 ◽  
Author(s):  
Bruce J. MacFadden
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Morphological Evolution ◽  
Natural Populations ◽  
Evolutionary Rates ◽  
Middle Pleistocene ◽  
Gradual Change ◽  
Regression Equations ◽  
Extant Species ◽  
Body Sizes

The evolution of body size in fossil horses is frequently depicted as a gradual, progressive trend toward increased body size (Cope's Law). Body size (actually body mass) was estimated for 40 species of fossil horses using dental and skeletal characters and regression equations derived from the same characters in extant species of Equus with known body mass. After body sizes were estimated, rates of morphological evolution, in darwins (d), were calculated between known ancestral and descendant fossil horse species. For the first half of horse evolution (from ca. 57 to 25 ma) body mass remained relatively static between about 25 and 50 kg with very slow evolutionary rates of 0.003–0.04 d. During the early–middle Miocene (from ca. 25 to 10 ma) there was a major diversification of body mass to about 75–400 kg and consistently higher evolutionary rates between 0.04 and 0.24 d. Since the late Miocene, body mass has generally increased with a maximum seen (in natural populations) in Equus scotti (ca. 500 kg) during the middle Pleistocene. Therefore, for horses, the traditional interpretation of gradual increase in body size through time is oversimplified because: (1) although the exception to the rule, 5 of 24 species lineages studied are characterized by dwarfism; and (2) the general trend seems to have been a long period (32 ma) of relative stasis followed by 25 ma of diversification and progressive (although not necessarily gradual) change in body size.

Hierarchy and the reconstruction of evolutionary trends: evidence for constraints on the evolution of body size in terrestrial caniform carnivorans (Mammalia)

Paleobiology ◽  
2008 ◽  
Vol 34 (4) ◽  
pp. 553-562 ◽  
Author(s):  
John A. Finarelli
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Small Body ◽  
Information Criterion ◽  
Size Increase ◽  
Size Evolution ◽  
Species Pairs ◽  
Body Sizes ◽  
Intermediate Size ◽  
Body Size Evolution

Body mass is an important organism-level variable in mammalian biology, correlated with physiology, life history, and ecology. To analyze the dynamics of body size evolution, increases and decreases in body mass were tallied for ancestor-descendant (AD) species pairs for 519 terrestrial caniform taxa. To account for uncertainty phylogeny, a bootstrapping routine shuffled hypothesized AD pairs, and average proportions of increases were binned as a function of ancestral body mass. A set of models relating the rate of body size increase were evaluated with the Akaike Information Criterion (AIC). AIC selected three models of the candidate set as equivalent in support by the observed body mass data. These three models propose body size increase for small AD pairs and body size decrease for large AD pairs, although they differ in their treatment of taxa at intermediate sizes.These results demonstrate the presence of constraints bounding the caniform distribution at large and small body sizes, stabilizing the distribution through time, which stands in contrast to a broader mammalian pattern. At a finer phylogenetic scale, subclades within intermediate size classes display proportions that are significantly different from unbiased, with several clades previously cited as examples of “Cope's Rule” showing biased increases in size, and basal mustelids (badgers, and allied genera), Mephitidae (skunks), and Vulpini (“foxes”) exhibiting biased decreases. The caniform pattern is therefore the result of superimposed, clade-specific trajectories, demonstrating that the inferred dynamics of body size evolution and even the direction of trends in body size evolution within the Caniformia, and for mammals in general, depend on the hierarchical scale of the analysis.

Body mass index during adolescence, rather than childhood, is critical in determining MS risk

2015 ◽  
Vol 22 (7) ◽  
pp. 878-883 ◽  
Author(s):  
AK Hedström ◽  
T Olsson ◽  
L Alfredsson
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Population Based ◽  
Adolescent Obesity ◽  
Risk Genes ◽  
Increased Risk ◽  
Body Sizes ◽  
Childhood And Adolescent Obesity ◽  
Size At Age ◽  
Potential Interactions

Objective: Obesity in childhood and during adolescence has repeatedly been associated with increased risk of developing multiple sclerosis (MS). We aimed to investigate whether the most critical period occurs during childhood or later, during adolescence. Methods: Using a population-based case-control study (1586 cases and 2800 controls), individuals with different body sizes at age 10 and different body mass indices at age 20 were compared regarding MS risk, by calculating odds ratios with 95% confidence intervals. Potential interactions between HLA-DRB1*15 and absence of HLA-A*02, respectively, and both childhood and adolescent obesity were evaluated by calculating the attributable proportion due to interaction. Results: Regardless of body size at age 10, individuals with adolescent obesity had a 90% increased risk of MS. Among participants who were not obese at age 20, no association was observed between body size at age 10 and subsequent MS risk. An interaction was observed between the HLA MS risk genes and adolescent, but not childhood, obesity. Conclusions: Our results suggest that BMI during adolescence, rather than childhood, is critical in determining MS risk.

scholarly journals Sex-specific covariance between metabolic rate, behaviour and morphology in the ground beetle Carabus hortensis

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12455
Author(s):  
Elisabeth Yarwood ◽  
Claudia Drees ◽  
Jeremy E. Niven ◽  
Wiebke Schuett
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Body Mass ◽  
Ground Beetle ◽  
Exploratory Behaviour ◽  
Temperature Dependent ◽  
Sexual Dimorphisms ◽  
Individual Fitness ◽  
Body Sizes ◽  
Mass Dependent

Background Individuals within the same species often differ in their metabolic rates, which may covary with behavioural traits (such as exploration), that are consistent across time and/or contexts, and morphological traits. Yet, despite the frequent occurrence of sexual dimorphisms in morphology and behaviour, few studies have assessed whether and how sexes differ in metabolic trait covariances. Methods We investigated sex-specific relationships among resting or active metabolic rate (RMR and AMR, respectively) with exploratory behaviour, measured independently of metabolic rate in a novel environment, body size and body mass, in Carabus hortensis ground beetles. Results RMR, AMR and exploratory behaviour were repeatable among individuals across time, except for male RMR which was unrepeatable. Female RMR neither correlated with exploratory behaviour nor body size/body mass. In contrast, AMR was correlated with both body size and exploratory behaviour. Males with larger body sizes had higher AMR, whereas females with larger body sizes had lower AMR. Both male and female AMR were significantly related to exploratory behaviour, though the relationships between AMR and exploration were body mass-dependent in males and temperature-dependent in females. Discussion Differences between sexes exist in the covariances between metabolic rate, body size and exploratory behaviour. This suggests that selection acts differently on males and females to produce these trait covariances with potentially important consequences for individual fitness.

Children's Perceptions of Their Current and Ideal Body Sizes and Body Mass Index

1996 ◽  
Vol 82 (2) ◽  
pp. 651-656 ◽  
Author(s):  
Kim Rolland ◽  
Douglas Farnill ◽  
Rosalyn A. Griffiths
Keyword(s):  
Body Mass Index ◽  
Body Size ◽  
Actual Body ◽  
Body Mass ◽  
Reference Data ◽  
Recent Literature ◽  
Overweight Children ◽  
International Reference ◽  
Body Sizes ◽  
Ideal Body

244 Australian schoolchildren aged between 8 and 12 years indicated their current and ideal body sizes by means of Collins' pictorial figures. Children's height and weight were also measured. Body-mass indices were calculated from these data, and percentile ranks estimated according to international reference data. Consistent with Collins' findings, 39% of girls and 26% of boys wanted to be thinner than they perceived themselves to be; however, this desire was strongly related to actual body size so the percentages were very different for weight categories established on the basis of Body Mass Index. In the overweight quartile, 76% of girls and 56% of boys wanted to be thinner, whereas in the underweight quartile only 10% of girls and no boys wanted to be thinner. The response of overweight children may be sensible, but the desire of some underweight girls to be even thinner is of concern. Some recent literature suggests that underweight individuals tend to overestimate their body sizes. About a half of our underweight children slightly overestimated their body sizes but only one child overestimated grossly.

scholarly journals Pesticide use is linked to increased body size in a large mammalian carnivore

2020 ◽  
Vol 131 (1) ◽  
pp. 220-229
Author(s):  
M Letnic ◽  
M S Crowther
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Intraspecific Competition ◽  
Chemical Resistance ◽  
Prey Availability ◽  
Phenotypic Change ◽  
Pesticide Use ◽  
Skull Length ◽  
Before And After

Abstract Pollution and pesticide use have been linked to evolution of chemical resistance and phenotypic shifts in invertebrates, but less so in vertebrates. Here we provide evidence that poisoning directed towards a mammalian carnivore, the dingo (Canis dingo), is linked to an increase in dingo body mass. We compared the skull length of dingoes, a proxy for size, from three regions where dingo populations were controlled by distributing poisoned meat baits and an unbaited region, before and after the introduction of the toxin sodium fluoroacetate (Compound 1080). Following 1080 introduction, dingo skull length increased in baited regions but not in the unbaited region. We estimate that after 1080 introduction, the skull length of female and male dingoes in baited regions increased by 4.49 and 3.6 mm, respectively. This equates to a 1.02- and 0.86-kg increase in mean body masses of female and male dingoes, respectively. We hypothesize that dingo body size has increased in baited regions due to 1080 selecting for animals with larger body size or because a reduction in dingo abundance in baited areas may have removed constraints on growth imposed by intraspecific competition and prey availability. Our study provides evidence that pesticide use can prompt phenotypic change in comparatively large and long-lived large vertebrates.

scholarly journals The allometry between secondary sexual traits and body size is nonlinear among cervids

2014 ◽  
Vol 10 (3) ◽  
pp. 20130869 ◽  
Author(s):  
J. F. Lemaître ◽  
C. Vanpé ◽  
F. Plard ◽  
J. M. Gaillard
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Life History Theory ◽  
Male Body ◽  
Allometric Relationships ◽  
Secondary Sexual Traits ◽  
Sexually Selected Traits ◽  
Large Size ◽  
Antler Size ◽  
Selected Traits

Allometric relationships between sexually selected traits and body size have been extensively studied in recent decades. While sexually selected traits generally display positive allometry, a few recent reports have suggested that allometric relationships are not always linear. In male cervids, having both long antlers and large size provides benefits in terms of increased mating success. However, such attributes are costly to grow and maintain, and these costs might constrain antler length from increasing at the same rate as body mass in larger species if the quantity of energy that males can extract from their environment is limiting. We tested for possible nonlinearity in the relationship between antler size and body mass (on a log–log scale) among 31 cervids and found clear deviation from linearity in the allometry of antler length. Antler length increased linearly until a male body mass threshold at approximately 110 kg. Beyond this threshold, antler length did not change with increasing mass. We discuss this evidence of nonlinear allometry in the light of life-history theory and stress the importance of testing for nonlinearity when studying allometric relationships.

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