scholarly journals Concurrent evolution of anti-aging gene duplications and cellular phenotypes in long-lived turtles

2021 ◽  
Author(s):  
Scott Glaberman ◽  
Stephanie E. Bulls ◽  
Juan Manuel Vazquez ◽  
Ylenia Chiari ◽  
Vincent J Lynch
Keyword(s):  
Body Size ◽  
Large Body ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Gene Duplications ◽  
Different Types ◽  
Body Sizes ◽  
Multiple Species ◽  
Cytotoxic Stress ◽  
Cellular Phenotypes

There are many costs associated with increased body size and longevity in animals, including the accumulation of genotoxic and cytotoxic damage that comes with having more cells and living longer. Yet, some species have overcome these barriers and have evolved remarkably large body sizes and long lifespans, sometimes within a narrow window of evolutionary time. Here, we demonstrate through phylogenetic comparative analysis that multiple turtle lineages, including Galapagos giant tortoises, concurrently evolved large bodies, long lifespans, and reduced cancer risk. We also show through comparative genomic analysis that Galapagos giant tortoises have gene duplications related to longevity and tumor suppression. To examine the molecular basis underlying increased body size and lifespan in turtles, we treated cell lines from multiple species, including Galapagos giant tortoises, with drugs that induce different types of cytotoxic stress. Our results indicate that turtle cells, in general, are resistant to oxidative stress related to aging, while Galapagos giant tortoise cells, specifically, are sensitive to endoplasmic reticulum stress, which may give this species an ability to mitigate the effects of cellular stress associated with increased body size and longevity.

scholarly journals Size- and sex-specific predation on dung flies by amphibian and arthropod predators – size match matters

2019 ◽  
Author(s):  
Wolf U. Blanckenhorn ◽  
Gabriele Cozzi ◽  
Gregory Jäggli ◽  
Juan Pablo Busso
Keyword(s):  
Body Size ◽  
Sexual Size Dimorphism ◽  
Rana Temporaria ◽  
Large Body ◽  
Mechanistic Study ◽  
Mating Activity ◽  
Size Dimorphism ◽  
Arthropod Predators ◽  
Body Sizes ◽  
Predation Rates

Because predator-prey interactions in nature are multifarious, linking phenomenological predation rates to the underlying behavioural or ecological mechanisms is challenging. Size- and sex-specific predation has been implicated as a major selective force keeping animals small, affecting the evolution of body size and sexual size dimorphism. We experimentally assessed predation by various amphibian (frogs and toads) and arthropod predators (bugs, flies, spiders) on three species of dung flies with similar ecology but contrasting body sizes, sexual size dimorphism and coloration. Predators were offered a size range of flies in single- or mixed-sex groups. As expected based on optimal foraging theory, some anurans (e.g. Bufo bufo) selected larger prey, thus selecting against large body size of the flies, while others (Bombina variagata and Rana esculenta) showed no such pattern. Small juvenile Rana temporaria metamorphs, in contrast, preferred small flies, as did all arthropod predators, a pattern that can be explained by larger prey being better at escaping. The more mobile males were not eaten more frequently or faster than the cryptic females, even when conspicuously colored. Predation rates on flies in mixed groups permitting mating activity were not higher, contrary to expectation, nor was predation generally sex-specific. We conclude that the size-selectivity of predators, and hence the viability selection pattern exerted on their prey, depends foremost on the relative body sizes of the two in a continuous fashion. Sex-specific predation by single predators appears to contribute little to sexual dimorphism. Therefore, the mechanistic study of predation requires integration of both the predator’s and the prey’s perspectives, and phenomenological field studies of predation remain indispensable.

scholarly journals The first juvenile specimens of Plateosaurus engelhardti from Frick, Switzerland: Isolated neural arches and their implications for developmental plasticity in a basal sauropodomorph

2014 ◽  
Author(s):  
Rebecca Hofmann ◽  
P. Martin Sander
Keyword(s):  
Body Size ◽  
Developmental Plasticity ◽  
Large Body ◽  
Late Triassic ◽  
Poor Correlation ◽  
Time Averaging ◽  
Large Body Size ◽  
Alternative Hypotheses ◽  
Histological Data ◽  
Multiple Species

The dinosaur Plateosaurus engelhardti is the most abundant dinosaur in the Late Triassic of Europe and the best known basal sauropodomorph. Plateosaurus engelhardti was one of the first sauropdomorph dinosaurs to display a large body size. Remains can be found in the Norian stage of the Late Triassic in over 40 localities in Central Europe (France, Germany, Greenland and Switzerland). Since the first discovery of P. engelhardti no juvenile specimens of this species had been found. Here we describe the first remains of juvenile individuals, isolated cervical and dorsal neural arches. These were separated postmortem from their respective centra because of unfused neurocentral sutures. However the specimens share the same neural arch morphology found in adults. Morphometric analysis suggests a body lengths of the juvenile indivduals that is greater than those of most adult specimens. This supports the hypothesis of developmental plasticity in Plateosaurus engelhardti that previously had been based on histological data only. Alternative hypotheses for explaining the poor correlation between ontogenetic stage and size in this taxon are multiple species or sexual morphs with little morphological variance or time-averaging of individuals from populations differing in body size.

scholarly journals The first juvenile specimens of Plateosaurus engelhardti from Frick, Switzerland: Isolated neural arches and their implications for developmental plasticity in a basal sauropodomorph

2014 ◽  
Author(s):  
Rebecca Hofmann ◽  
P. Martin Sander
Keyword(s):  
Body Size ◽  
Developmental Plasticity ◽  
Large Body ◽  
Late Triassic ◽  
Poor Correlation ◽  
Time Averaging ◽  
Large Body Size ◽  
Alternative Hypotheses ◽  
Histological Data ◽  
Multiple Species

The dinosaur Plateosaurus engelhardti is the most abundant dinosaur in the Late Triassic of Europe and the best known basal sauropodomorph. Plateosaurus engelhardti was one of the first sauropdomorph dinosaurs to display a large body size. Remains can be found in the Norian stage of the Late Triassic in over 40 localities in Central Europe (France, Germany, Greenland and Switzerland). Since the first discovery of P. engelhardti no juvenile specimens of this species had been found. Here we describe the first remains of juvenile individuals, isolated cervical and dorsal neural arches. These were separated postmortem from their respective centra because of unfused neurocentral sutures. However the specimens share the same neural arch morphology found in adults. Morphometric analysis suggests a body lengths of the juvenile indivduals that is greater than those of most adult specimens. This supports the hypothesis of developmental plasticity in Plateosaurus engelhardti that previously had been based on histological data only. Alternative hypotheses for explaining the poor correlation between ontogenetic stage and size in this taxon are multiple species or sexual morphs with little morphological variance or time-averaging of individuals from populations differing in body size.

scholarly journals How to make a rodent giant: Genomic basis and tradeoffs of gigantism in the capybara, the world’s largest rodent

2020 ◽  
Author(s):  
Santiago Herrera-Álvarez ◽  
Elinor Karlsson ◽  
Oliver A Ryder ◽  
Kerstin Lindblad-Toh ◽  
Andrew J Crawford
Keyword(s):  
Body Size ◽  
Draft Genome ◽  
Large Body ◽  
Comparative Genomic ◽  
Specific Gene ◽  
Large Body Size ◽  
Synonymous Mutations ◽  
Intragenomic Conflict ◽  
Genome Wide ◽  
A Genome

Abstract Gigantism results when one lineage within a clade evolves extremely large body size relative to its small-bodied ancestors, a common phenomenon in animals. Theory predicts that the evolution of giants should be constrained by two tradeoffs. First, because body size is negatively correlated with population size, purifying selection is expected to be less efficient in species of large body size, leading to increased mutational load. Second, gigantism is achieved through generating a higher number of cells along with higher rates of cell proliferation, thus increasing the likelihood of cancer. To explore the genetic basis of gigantism in rodents and uncover genomic signatures of gigantism-related tradeoffs, we assembled a draft genome of the capybara (Hydrochoerus hydrochaeris), the world’s largest living rodent. We found that the genome-wide ratio of non-synonymous to synonymous mutations (ω) is elevated in the capybara relative to other rodents, likely caused by a generation-time effect and consistent with a nearly-neutral model of molecular evolution. A genome-wide scan for adaptive protein evolution in the capybara highlighted several genes controlling post-natal bone growth regulation and musculoskeletal development, which are relevant to anatomical and developmental modifications for an increase in overall body size. Capybara-specific gene-family expansions included a putative novel anticancer adaptation that involves T cell-mediated tumor suppression, offering a potential resolution to the increased cancer risk in this lineage. Our comparative genomic results uncovered the signature of an intragenomic conflict where the evolution of gigantism in the capybara involved selection on genes and pathways that are directly linked to cancer.

“She was neither unduly fat nor lanky”: Representation of body size and beauty in the novels of Daniel O. Fágúnwà

2020 ◽  
Vol 18 (1) ◽  
pp. 131-147
Author(s):  
Fausat Motunrayo Ibrahim ◽  
Ayodele S. Jegede
Keyword(s):  
Body Size ◽  
Large Body ◽  
African Literature ◽  
Thin Structure ◽  
Self Worth ◽  
Body Sizes ◽  
Definition Of

The climate of thought regarding beauty characterization among Africans and other people of colour portrays the large body as beautiful. This reflects that body size and beauty is racially and culturally expressive, making it apposite to be disparate in advancing related discourses. This is particularly important because such discourses can influence Africans’ evaluation of their self-worth. The concerns generated by the global rise in obesity further create interest in these issues. African literature offers a fine and disparate platform to understand social realities. Consequently, relevant contents of the five precedent Yorùbá novels of Daniel Fágúnwà including Igbó Olódùmarè, Ìrèké Oníbùdó,Ògbójú ọdẹ nínú Igbó Irúnmọlè, Ìrìnkèrindò nínú Igbó Elégbèje and Àdììtú Olódùmarè were extracted and analyzed to examine association of beauty with body sizes. Findings reflect more of bipolarity in the definition of beauty, such that the none-fat/none-thin structure is conveyed as beautiful. Concurrently, the fat and the thin is also portrayed as beautiful, making ‘body size’ definition of beauty to be elusive, and strongly suggesting neutrality to body size among the Yorùbá. This is strongly borne out of Fágúnwà’s and indeed, Yorùbá construction of beauty from a ‘character’ perspective. Character (ìwà) is staunchly expounded as constituting beauty. The beautiful body size is indeterminate in Fágúnwà’s narratives and indeed, in Yorùbá thought.

Prey preference of a wasp determined by nest size supports the role of natural selection in body size evolution in Cassidinae leaf beetles

2021 ◽  
Author(s):  
Tadashi Shinohara ◽  
Yasuoki Takami
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Prey Species ◽  
Large Body ◽  
Size Variation ◽  
Prey Preference ◽  
Nest Size ◽  
Large Prey ◽  
Leaf Beetles ◽  
Body Sizes

Abstract The prey preference of a predator can impose natural selection on prey phenotypes, including body size. Despite evidence that large body size protects against predation in insects, the determinants of body size variation in Cassidinae leaf beetles are not well understood. We examined the prey preference of the digger wasp Cerceris albofasciata, a specialist predator of adult Cassidinae leaf beetles, and found evidence for natural selection on prey body size. The wasp hunted prey smaller than the size of their nest entrance. However, the wasp preferred larger prey species among those that could be carried into their nest. Thus, the benefits of large prey and the cost associated with nest expansion might determine the prey size preference. As expected from the prey species preference, the wasp preferred small individuals of the largest prey species, Thlaspida biramosa, and large individuals of the smallest prey species, Cassida piperata, resulting in natural selection on body sizes. In intermediate-sized prey species, however, there was no evidence for selection on body size. Natural selection on body size might explain the variation of prey morphologies that increase body size, such as explanate margins, in this group.

Traditional Attenuation of Inequality: Neutral Meaning of Body Size among the Yorùbá of Southwestern Nigeria

2020 ◽  
pp. 1-25
Author(s):  
Fausat M. Ibrahim ◽  
Ayodele S. Jegede
Keyword(s):  
Body Size ◽  
Phenomenological Study ◽  
Large Body ◽  
Human Person ◽  
Group Discussions ◽  
Southwestern Nigeria ◽  
Good Person ◽  
Body Sizes ◽  
Globalized World ◽  
Depth Interviews

Abstract Body size is a profound ground of inequality in modern global society. Moreover, constructions of body size are racially polarized, with blacks being reputed for venerating large body. Proceeding with a triangulation of qualitative methods, this phenomenological study featured forty-two in-depth interviews, eight focus group discussions and eighteen key informant interviews among men and women of varying body sizes in two of the six states of southwestern Nigeria. Findings reflect dominantly neutral meaning of body size among the Yorùbá. This neutrality is dominantly reflected in the literal questioning of meaning that Yorùbá attach to body size, and who becomes a king in Yorùbá land but partially neutral in acceptability of prospective son or daughter in-law. Divinity, orí (fate), ìwà (good behavior) and ọmọlúàbí (good person) are among phenomena that counts in discerning people’s worth. Meaning attached to body size is opposed to common-place attitude to body size, making this attitude to be profane while meaning is solemn. This meaning is tremendously in favour of optimum health, and attenuating inequality, for which even black societies are perpetrating in the globalized world. Traditional Yorùbá value of human person is irrespective of body size.

scholarly journals TP53 copy number expansion is associated with the evolution of increased body size and an enhanced DNA damage response in elephants

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Michael Sulak ◽  
Lindsey Fong ◽  
Katelyn Mika ◽  
Sravanthi Chigurupati ◽  
Lisa Yon ◽  
...  
Keyword(s):  
Dna Damage ◽  
Body Size ◽  
Signaling Pathway ◽  
Copy Number ◽  
Large Body ◽  
Genotoxic Stress ◽  
Suppressor Gene ◽  
Direct Role ◽  
Increased Risk ◽  
Body Sizes

A major constraint on the evolution of large body sizes in animals is an increased risk of developing cancer. There is no correlation, however, between body size and cancer risk. This lack of correlation is often referred to as 'Peto's Paradox'. Here, we show that the elephant genome encodes 20 copies of the tumor suppressor gene TP53 and that the increase in TP53 copy number occurred coincident with the evolution of large body sizes, the evolution of extreme sensitivity to genotoxic stress, and a hyperactive TP53 signaling pathway in the elephant (Proboscidean) lineage. Furthermore, we show that several of the TP53 retrogenes (TP53RTGs) are transcribed and likely translated. While TP53RTGs do not appear to directly function as transcription factors, they do contribute to the enhanced sensitivity of elephant cells to DNA damage and the induction of apoptosis by regulating activity of the TP53 signaling pathway. These results suggest that an increase in the copy number of TP53 may have played a direct role in the evolution of very large body sizes and the resolution of Peto's paradox in Proboscideans.

scholarly journals Predation selectively culls medium-sized species from island mammal faunas

2014 ◽  
Vol 10 (4) ◽  
pp. 20131066 ◽  
Author(s):  
Emily Hanna ◽  
Marcel Cardillo
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Large Body ◽  
Conservation Strategies ◽  
Size Selectivity ◽  
Introduced Predators ◽  
Body Sizes ◽  
Mammal Faunas ◽  
Species Declines ◽  
Risk Association

Globally, elevated extinction risk in mammals is strongly associated with large body size. However, in regions where introduced predators exert strong top-down pressure on mammal populations, the selectivity of extinctions may be skewed towards species of intermediate body size, leading to a hump-shaped relationship between size and extinction risk. The existence of this kind of extinction pattern, and its link to predation, has been contentious and difficult to demonstrate. Here, we test the hypothesis of a hump-shaped body size–extinction relationship, using a database of 927 island mammal populations. We show that the size-selectivity of extinctions on many islands has exceeded that expected under null models. On islands with introduced predators, extinctions are biased towards intermediate body sizes, but this bias does not occur on islands without predators. Hence, on islands with a large-bodied mammal fauna, predators are selectively culling species from the lower end of the size distribution, and on islands with a small-bodied fauna they are culling species from the upper end. These findings suggest that it will be difficult to use predictable generalizations about extinction patterns, such as a positive body size–extinction risk association, to anticipate future species declines and plan conservation strategies accordingly.

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