Exaggerated sexually selected weapons maintained with disproportionately low metabolic costs in a single species with extreme size variation

2021 ◽  
Author(s):  
Ummat Somjee ◽  
Erin C Powell ◽  
Anthony J Hickey ◽  
Jon F Harrison ◽  
Christina J Painting
Keyword(s):  
Size Variation ◽  
Single Species ◽  
Metabolic Costs

scholarly journals New footprints from Laetoli (Tanzania) provide evidence for marked body size variation in early hominins

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Fidelis T Masao ◽  
Elgidius B Ichumbaki ◽  
Marco Cherin ◽  
Angelo Barili ◽  
Giovanni Boschian ◽  
...  
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Size Variation ◽  
Single Species ◽  
Australopithecus Afarensis ◽  
Body Size Variation ◽  
Northern Tanzania ◽  
The World ◽  
Marked Body ◽  
Considerable Body

Laetoli is a well-known palaeontological locality in northern Tanzania whose outstanding record includes the earliest hominin footprints in the world (3.66 million years old), discovered in 1978 at Site G and attributed to Australopithecus afarensis. Here, we report hominin tracks unearthed in the new Site S at Laetoli and referred to two bipedal individuals (S1 and S2) moving on the same palaeosurface and in the same direction as the three hominins documented at Site G. The stature estimates for S1 greatly exceed those previously reconstructed for Au. afarensis from both skeletal material and footprint data. In combination with a comparative reappraisal of the Site G footprints, the evidence collected here embodies very important additions to the Pliocene record of hominin behaviour and morphology. Our results are consistent with considerable body size variation and, probably, degree of sexual dimorphism within a single species of bipedal hominins as early as 3.66 million years ago.

scholarly journals Size and Shape: Morphology's Impact on Human Speed and Mobility

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Cara M. Wall-Scheffler
Keyword(s):  
Sexual Dimorphism ◽  
Metabolic Rate ◽  
Reproductive Strategies ◽  
Walking Speed ◽  
Size Variation ◽  
Human Populations ◽  
Optimal Speed ◽  
Metabolic Costs ◽  
Walking Speeds ◽  
Tibia Length

While human sexual dimorphism is generally expected to be the result of differential reproductive strategies, it has the potential to create differences in the energetics of locomotion and the speed at which each morph travels, particularly since people have been shown to choose walking speeds around their metabolic optimum. Here, people of varying sizes walked around a track at four self-selected speeds while their metabolic rate was collected, in order to test whether the size variation within a population could significantly affect the shape of the optimal walking curve. The data show that larger people have significantly faster optimal walking speeds, higher costs at their optimal speed, and a more acute optimal walking curve (thus an increased penalty for walking at suboptimal speeds). Bigger people who also have wider bitrochanteric breadths have lower metabolic costs at their minimum than bigger people with a more narrow bitrochanteric breadth. Finally, tibia length significantly positively predicts optimal walking speed. These results suggest sex-specific walking groups typical of living human populations may be the result of energy maximizing strategies. In addition, testable hypotheses of group strategies are put forth.

scholarly journals No general relationship between mass and temperature in endothermic species

2017 ◽  
Author(s):  
Kristina Riemer ◽  
Robert P Guralnick ◽  
Ethan White
Keyword(s):  
Global Warming ◽  
Size Variation ◽  
Single Species ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Mammal Species ◽  
Data Intensive ◽  
Multiple Processes ◽  
Intensive Approach ◽  
Individual Mass

Bergmann’s rule is a widely-accepted biogeographic rule stating that individuals within a species are smaller in warmer environments. While there are many single-species studies and integrative reviews documenting this pattern, a data-intensive approach has not been used yet to determine the generality of this pattern. We assessed the strength and direction of the intraspecific relationship between temperature and individual mass for 952 bird and mammal species. For eighty-seven percent of species, temperature explained less than 10% of variation in mass, and for 79% of species the correlation was not statistically significant. These results suggest that Bergmann’s rule is not general and temperature is not a dominant driver of biogeographic variation in mass. Further understanding of size variation will require integrating multiple processes that influence size. The lack of dominant temperature forcing weakens the justification for the hypothesis that global warming could result in widespread decreases in body size.

scholarly journals Metabolic costs of brain size evolution

2006 ◽  
Vol 2 (4) ◽  
pp. 557-560 ◽  
Author(s):  
Karin Isler ◽  
Carel P van Schaik
Keyword(s):  
Brain Size ◽  
Size Variation ◽  
Brain Evolution ◽  
Energy Costs ◽  
Main Interest ◽  
Ecological Benefits ◽  
Size Evolution ◽  
Large Brain ◽  
Metabolic Costs ◽  
Cognitive Benefits

Abstract In the ongoing discussion about brain evolution in vertebrates, the main interest has shifted from theories focusing on energy balance to theories proposing social or ecological benefits of enhanced intellect. With the availability of a wealth of new data on basal metabolic rate (BMR) and brain size and with the aid of reliable techniques of comparative analysis, we are able to show that in fact energetics is an issue in the maintenance of a relatively large brain, and that brain size is positively correlated with the BMR in mammals, controlling for body size effects. We conclude that attempts to explain brain size variation in different taxa must consider the ability to sustain the energy costs alongside cognitive benefits.

scholarly journals No general relationship between mass and temperature in endothermic species

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Kristina Riemer ◽  
Robert P Guralnick ◽  
Ethan P White
Keyword(s):  
Global Warming ◽  
Size Variation ◽  
Single Species ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Mammal Species ◽  
Data Intensive ◽  
Multiple Processes ◽  
Intensive Approach ◽  
Individual Mass

Bergmann's rule is a widely-accepted biogeographic rule stating that individuals within a species are smaller in warmer environments. While there are many single-species studies and integrative reviews documenting this pattern, a data-intensive approach has not been used yet to determine the generality of this pattern. We assessed the strength and direction of the intraspecific relationship between temperature and individual mass for 952 bird and mammal species. For eighty-seven percent of species, temperature explained less than 10% of variation in mass, and for 79% of species the correlation was not statistically significant. These results suggest that Bergmann's rule is not general and temperature is not a dominant driver of biogeographic variation in mass. Further understanding of size variation will require integrating multiple processes that influence size. The lack of dominant temperature forcing weakens the justification for the hypothesis that global warming could result in widespread decreases in body size.

scholarly journals Caste and wing loading in a social wasp (Hymenoptera, Vespidae, Dolichovespula maculata)

2021 ◽  
Vol 84 ◽  
pp. 381-390
Author(s):  
Christopher K. Starr ◽  
Robert S. Jacobson ◽  
Joan W. Krispyn ◽  
Joshua A. Spiers
Keyword(s):  
Body Weight ◽  
General Pattern ◽  
Size Variation ◽  
Single Species ◽  
Social Wasp ◽  
Wing Size ◽  
Wing Loading ◽  
Flying Insects ◽  
The Social ◽  
Dolichovespula Maculata

Variation in wing design and wing loading according to body weight is well studied across taxa of birds and flying insects. Comparable studies have not been made in the few insects that show substantial size variation within the same phenon of a single species. We examine body measures of adults of the social wasp Dolichovespula maculata (Linnaeus, 1763), with particular attention to the limbs and wing loading. As expected, measures of the length of the legs scales isometrically with overall body weight and size. Against expectation, wing size also scales isometrically with body weight and size. This does not match the general pattern of comparison across species of flying animals, in which larger individuals have relatively larger wings, as a partial compensation for greater wing loading. We suggest that wing size in D. maculata may be constrained by the demands of life in a crowded nest.

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

A STUDY ON ICHTHYO-DIVERSITY OF MUNTJIBPUR POND OF ALLAHABAD (U.P.) INDIA

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
ASHOK KUMAR VERMA
Keyword(s):  
Single Species ◽  
Single Genus ◽  
One Year

An attempt was made to find the ichthyo-diversity of Muntjibpur pond of Allahabad. Systematic surveys were conducted during a period of one year. A total of 13 species of fishes belonging to 12 genera, 8 families and 5 orders were identified. Siluriformes order is represented by 5 genera and 5 species while Cypriniformes order by 4 genera and 5 species. Each of the orders Clupeiformes, Osteoglossiformes and Ophiocephaliformes is represented by single genus and single species.

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