Primary productivity, deoxygenation, and the Gulliver-absence effect determine bivalve body size following the end-Permian mass extinction

2020 ◽  
Author(s):  
Melanie Tietje ◽  
William J. Foster ◽  
Jana Gliwa ◽  
Clara Lembke ◽  
Autumn Pugh ◽  
...  
Keyword(s):  
Body Size ◽  
Ocean Circulation ◽  
Mass Extinction ◽  
The Body ◽  
Large Species ◽  
Mass Extinctions ◽  
Shell Size ◽  
Body Sizes ◽  
Permian Mass Extinction ◽  
The Impact

<p> The impact of mass extinctions on the body sizes of animals has received considerable attention and debate, as to whether the reduced size of post-extinction organisms is due to the selective extinction of large species, absence of large species as a stochastic effect of low-diversity faunas, or a size decrease within surviving genera and species. Here, we investigated the body sizes of bivalves following the end-Permian mass extinction event and show that the shell size increase of bivalve genera was driven by both evolutionary and ecophenotypic responses. First, some genera show significant increases in body size with the evolution of new species. Further, the same genera record significant within-species increases in average and maximum body size into the late Induan, indicating that ecophenotypic changes were also involved on long-term body size trends. These increases are associated with invigorated ocean circulation, improved oxygenation of the seafloor, and probably increased food supply.</p>

Mass extinctions alter extinction and origination dynamics with respect to body size

2021 ◽  
Vol 288 (1960) ◽  
Author(s):  
Pedro M. Monarrez ◽  
Noel A. Heim ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Mass Extinction ◽  
Evolutionary Biology ◽  
Marine Animal ◽  
Mass Extinctions ◽  
Extinction Selectivity ◽  
Extinction Events ◽  
Mass Extinction Events ◽  
Marine Biosphere

Whether mass extinctions and their associated recoveries represent an intensification of background extinction and origination dynamics versus a separate macroevolutionary regime remains a central debate in evolutionary biology. The previous focus has been on extinction, but origination dynamics may be equally or more important for long-term evolutionary outcomes. The evolution of animal body size is an ideal process to test for differences in macroevolutionary regimes, as body size is easily determined, comparable across distantly related taxa and scales with organismal traits. Here, we test for shifts in selectivity between background intervals and the ‘Big Five’ mass extinction events using capture–mark–recapture models. Our body-size data cover 10 203 fossil marine animal genera spanning 10 Linnaean classes with occurrences ranging from Early Ordovician to Late Pleistocene (485–1 Ma). Most classes exhibit differences in both origination and extinction selectivity between background intervals and mass extinctions, with the direction of selectivity varying among classes and overall exhibiting stronger selectivity during origination after mass extinction than extinction during the mass extinction. Thus, not only do mass extinction events shift the marine biosphere into a new macroevolutionary regime, the dynamics of recovery from mass extinction also appear to play an underappreciated role in shaping the biosphere in their aftermath.

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.

Girth body dimensions in men and women with seborrheic dermatitis of varying severity

2021 ◽  
Vol 27 (4) ◽  
pp. 22-27
Author(s):  
Ahmad Raed Khasawneh ◽  
I.V. Serheta ◽  
N.V. Belik ◽  
A.O. Dovhan ◽  
I.I. Zhuchenko
Keyword(s):  
Body Size ◽  
Seborrheic Dermatitis ◽  
Severe Disease ◽  
Statistical Processing ◽  
Modern Medicine ◽  
The Body ◽  
Control Group ◽  
Men And Women ◽  
Healthy Men ◽  
Body Sizes

Today in modern medicine the study of human health is reoriented to the individual principle, which is based on the identification and study of constitutionally determined patterns of manifestation of certain diseases. The purpose of the study is to establish and analyze the features of the girth body sizes in men and women with generalized fatty form of seborrheic dermatitis of varying severity. The comprehensive body size of 40 men and 40 young women (25-44 years) with generalized fatty seborrheic dermatitis (mild and severe) was determined. The control group consisted of the girth sizes of practically healthy men (n=82) and women (n=154) of the same age group, which were selected from the database of the research center National Pirogov Memorial Medical University. Statistical processing of body circumference was performed in the licensed package “Statistica 6.0” using non-parametric evaluation methods. As a result of studies in patients with seborrheic dermatitis of varying severity of men, compared with practically healthy men, found only greater values of the girth of the shoulder in a relaxed state and thighs, neck (only mild), shin in the upper part and waist (in both cases only with a severe degree), as well as smaller values of the girth of the shoulder in a tense state; and in patients of varying severity of women – greater values of the girth of the shoulder in a relaxed state, thighs, lower legs, neck, waist and all girths of the chest and both thighs (only severe), as well as smaller values of the girth of the hand (only with mild). In both men and women with seborrheic dermatitis, differences in girth body sizes are more pronounced in people with severe disease. Between men or women with seborrheic dermatitis of varying severity, there are no significant or trends in differences in girth body sizes. In the analysis of the manifestations of sexual dimorphism of the circumferential body size between men and women with seborrheic dermatitis found greater values in men with mild and severe disease of the upper extremities, hands, shin, feet and neck (in most cases more pronounced in representatives with mild severity), as well as only in men with mild severity – greater values of all chest girths. For a more correct understanding of changes in girth body sizes in Ukrainian men or women with seborrheic dermatitis of varying severity, it is necessary to analyze other constitutional parameters of the body.

scholarly journals Exploring the Role of Insulin Signaling in Relative Growth: A Case Study on Wing-Body Scaling in Lepidoptera

2019 ◽  
Vol 59 (5) ◽  
pp. 1324-1337 ◽  
Author(s):  
Kenneth Z McKenna ◽  
Della Tao ◽  
H Frederik Nijhout
Keyword(s):  
Body Size ◽  
Insulin Signaling ◽  
The Body ◽  
Adult Size ◽  
Tor Signaling ◽  
Relative Growth ◽  
Laboratory Populations ◽  
Body Sizes ◽  
Specific Variation ◽  
Wing Growth

Abstract Adult forms emerge from the relative growth of the body and its parts. Each appendage and organ has a unique pattern of growth that influences the size and shape it attains. This produces adult size relationships referred to as static allometries, which have received a great amount of attention in evolutionary and developmental biology. However, many questions remain unanswered, for example: What sorts of developmental processes coordinate growth? And how do these processes change given variation in body size? It has become increasingly clear that nutrition is one of the strongest influences on size relationships. In insects, nutrition acts via insulin/TOR signaling to facilitate inter- and intra-specific variation in body size and appendage size. Yet, the mechanism by which insulin signaling influences the scaling of growth remains unclear. Here we will discuss the potential roles of insulin signaling in wing-body scaling in Lepidoptera. We analyzed the growth of wings in animals reared on different diet qualities that induce a range of body sizes not normally present in our laboratory populations. By growing wings in tissue culture, we survey how perturbation and stimulation of insulin/TOR signaling influences wing growth. To conclude, we will discuss the implications of our findings for the development and evolution of organismal form.

scholarly journals Body Size Differences between Foraging and Intranidal Workers of the Monomorphic Ant Lasius niger

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 433
Author(s):  
Mateusz Okrutniak ◽  
Bartosz Rom ◽  
Filip Turza ◽  
Irena M. Grześ
Keyword(s):  
Body Size ◽  
Field Experiment ◽  
Important Determinant ◽  
Size Variation ◽  
Division Of Labour ◽  
The Body ◽  
Food Type ◽  
Lasius Niger ◽  
Worker Size ◽  
Body Sizes

The association between the division of labour and worker body size of ants is typical for species that maintain physical castes. Some studies showed that this phenomenon can be also observed in the absence of distinct morphological subcastes among workers. However, the general and consistent patterns in the size-based division of labour in monomorphic ants are largely unidentified. In this study, we performed a field experiment to investigate the link between worker body size and the division of labour of the ant Lasius niger (Linnaeus, 1758), which displays limited worker size variation. We demonstrated that the body size of workers exploring tuna baits is slightly but significantly smaller than the size of workers located in the upper parts of the nest. Comparing the present results with existing studies, large workers do not seem to be dedicated to work outside the nest. We suggest that monomorphic workers of certain body sizes are flexible in the choice of task they perform, and food type may be the important determinant of this choice.

scholarly journals Devonian bryozoan extinction and diversification

1992 ◽  
Vol 6 ◽  
pp. 136-136
Author(s):  
Alan S. Horowitz ◽  
Joseph F. Pachut
Keyword(s):  
Mass Extinction ◽  
Taxonomic Diversity ◽  
Mass Extinctions ◽  
Random Mass ◽  
Number Of Species ◽  
Rugose Corals ◽  
Nomina Dubia ◽  
Extinction Model ◽  
Permian Mass Extinction ◽  
Devonian Extinction

The names proposed world-wide for Devonian bryozoans have been evaluated with respect to replaced names, synonyms, and nomina dubia [Horowitz and Pachut (1993), Journal of Paleontology, in press]. The resulting list contains 1738 specific names assigned to 199 genera in 45 families. Approximately 75% of Devonian bryozoan species are reported from a single stage. Not more than 10%, and usually 4–6%, of the species reported in any Devonian stage are also reported in the succeeding stage.The largest decrease in observed bryozoan diversity occurs between the Givetian and Frasnian stages, reducing the number of species by 77%, genera by 64%, and families by 42%. These values are less than those reported for the range-through method for the entire fauna of the Permian mass extinction (Raup, 1979) but larger than percentage extinctions (presumably based on range-though data) for four other Phanerozoic mass extinctions tabulated by Valentine and Walker (1987).The range-through method dampens the observed differences in taxonomic diversity among Devonian stages at all taxonomic levels. The range-through number of species/stage is based upon both direct applications of the range-through method and on the assignment of ranges known only to early, middle and late Devonian to include appropriate Devonian stages. Generic and familial diversity increases monotonically from Lochkovian through Givetian stages. Thereafter (Givetian to Frasnian), range-through values for specific (69%), generic (31%), and familial diversity (10%) decrease. Specific and familial decreases across the Givetian-Frasnian boundary are comparable to those reported for non-Permian mass extinctions by Valentine and Walker, but the generic decrease is not as great. These results are consistent with Valentine and Walker's random mass extinction model.Observed bryozoan diversity across the Frasnian-Famennian boundary increases while values calculated using the range-through method decrease by approximately 5–15%. This does not suggest a major bryozoan extinction event. Conversely, the decrease in bryozoan diversity across the Givetian-Frasnian interval is similar to an important Devonian extinction among rugose corals. The reason(s) for these extinctions is not yet clear. With respect to Devonian bryozoans, our inadequate understanding of the cause(s) of mass extinctions and the relatively coarse resolution of the stadial timescale does not permit differentiating between gradual or catastrophic scenarios.

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.

Quantifying the process and abruptness of the end-Permian mass extinction

Paleobiology ◽  
10.1666/13022 ◽  
2014 ◽  
Vol 40 (1) ◽  
pp. 113-129 ◽  
Author(s):  
Yue Wang ◽  
Peter M. Sadler ◽  
Shu-zhong Shen ◽  
Douglas H. Erwin ◽  
Yi-chun Zhang ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Statistical Treatment ◽  
Catastrophic Event ◽  
Optimal Sequence ◽  
Data Set ◽  
Meishan Section ◽  
Biotic Recovery ◽  
Biodiversity Pattern ◽  
Permian Mass Extinction ◽  
The Impact

Studies of the end-Permian mass extinction have suggested a variety of patterns from a single catastrophic event to multiple phases. But most of these analyses have been based on fossil distributions from single localities. Although single sections may simplify the interpretation of species diversity, they are susceptible to bias from stratigraphic incompleteness and facies control of preservation. Here we use a data set of 1450 species from 18 fossiliferous sections in different paleoenvironmental settings across South China and the northern peri-Gondwanan region, and integrate it with high-precision geochronologic data to evaluate the rapidity of the largest Phanerozoic mass extinction. To reduce the Signor-Lipps effect, we applied constrained optimization (CONOP) to search for an optimal sequence of first and last occurrence datums for all species and generate a composite biodiversity pattern based on multiple sections. This analysis indicates that an abrupt extinction of 62% of species took place within 200 Kyr. The onset of the sudden extinction is around 252.3 Ma, just below Bed 25 at the Meishan section. Taxon turnover and diversification rates suggest a deterioration of the living conditions nearly 1.2 Myr before the sudden extinction. The magnitude of the extinction was such that there was no immediate biotic recovery. Prior suggestions of highly variable, multi-phased extinction patterns reflect the impact of the Signor-Lipps effect and facies-dependent occurrences, and are not supported following appropriate statistical treatment of this larger data set.

scholarly journals Pre- versus post-mass extinction divergence of Mesozoic marine reptiles dictated by time-scale dependence of evolutionary rates

2017 ◽  
Vol 284 (1854) ◽  
pp. 20170241 ◽  
Author(s):  
Ryosuke Motani ◽  
Da-yong Jiang ◽  
Andrea Tintori ◽  
Cheng Ji ◽  
Jian-dong Huang
Keyword(s):  
High Resolution ◽  
Time Scale ◽  
Mass Extinction ◽  
Divergence Time ◽  
Temporal Characteristic ◽  
Evolutionary Rates ◽  
Morphological Data ◽  
Mass Extinctions ◽  
Marine Reptiles ◽  
Permian Mass Extinction

The fossil record of a major clade often starts after a mass extinction even though evolutionary rates, molecular or morphological, suggest its pre-extinction emergence (e.g. squamates, placentals and teleosts). The discrepancy is larger for older clades, and the presence of a time-scale-dependent methodological bias has been suggested, yet it has been difficult to avoid the bias using Bayesian phylogenetic methods. This paradox raises the question of whether ecological vacancies, such as those after mass extinctions, prompt the radiations. We addressed this problem by using a unique temporal characteristic of the morphological data and a high-resolution stratigraphic record, for the oldest clade of Mesozoic marine reptiles, Ichthyosauromorpha. The evolutionary rate was fastest during the first few million years of ichthyosauromorph evolution and became progressively slower over time, eventually becoming six times slower. Using the later slower rates, estimates of divergence time become excessively older. The fast, initial rate suggests the emergence of ichthyosauromorphs after the end-Permian mass extinction, matching an independent result from high-resolution stratigraphic confidence intervals. These reptiles probably invaded the sea as a new ecosystem was formed after the end-Permian mass extinction. Lack of information on early evolution biased Bayesian clock rates.

Reproductive patterns of European pond turtles differ between sites: a small scale scenario

2015 ◽  
Vol 36 (4) ◽  
pp. 339-349
Author(s):  
Marco A.L. Zuffi ◽  
Elena Foschi
Keyword(s):  
Body Size ◽  
Egg Production ◽  
Shell Height ◽  
The Body ◽  
Small Scale ◽  
Central Mediterranean ◽  
Population Structures ◽  
Body Sizes ◽  
Reproductive Females ◽  
Similar Body

From 1996 to 2002, we studied the body size, measures of reproductive strategy (relative clutch mass and delayed reproduction at sexual maturity), and reproductive output (clutch frequency and annual egg production) of female European Pond turtles,Emys orbicularis, at two sites separated by 12 km in central Mediterranean Tuscany (San Rossore and Camp Darby, central northern Italy). Females did not reproduce at the first appearance of external sexual characters, but reproduced at larger sizes, probably as older turtles. Among years, reproductive females were more common than were non-reproductive females, yet both groups had similar body sizes. Body size (carapace length and width, plastron length and width, shell height and body mass) varied between localities and among years. Body size differed between reproductive and non reproductive females in Camp Darby, but not in San Rossore females. Shell volume did not vary among years, nor between localities, nor between reproductive status. Reproductive females had higher body condition indices (BCI) than did non-reproductive females, while BCI did not differ between females laying one clutch and females laying multiple clutches. Clutch size did not vary among years. One clutch per year was much more frequent than multiple clutches, and multiple clutches were more frequent in Camp Darby than in San Rossore females, likely due to differences in population structures between sites.

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