scholarly journals Resurrection of the island rule – human-driven extinctions have obscured a basic evolutionary pattern

2015 ◽  
Author(s):  
Søren Faurby ◽  
Jens-Christian Svenning
Keyword(s):  
Late Quaternary ◽  
Strong Support ◽  
The Body ◽  
Island Rule ◽  
Evolutionary Patterns ◽  
Data Set ◽  
Evolutionary Pattern ◽  
Size Evolution ◽  
Body Sizes ◽  
The Many

Islands are or have been occupied by unusual species, such as dwarf proboscideans and giant rodents. The discussion of the classical but controversial “island rule,” which states that mammalian body sizes converge on intermediate sizes on islands, has been stimulated by these unusual species. In this paper, we use an unprecedented global data set of the distributions and the body sizes of mammals and a novel analytical method to analyze body size evolution on islands; the analyses produced strong support for the island rule. Islands have suffered massive human-driven losses of species, and we found that the support for the island rule was substantially stronger when the many late-Quaternary extinct species were also considered (particularly, the tendency for dwarfing in large taxa). In this study, the decisive support generated for the island rule confirmed that evolution is markedly different on islands and that human impact may obscure even fundamental evolutionary patterns.

scholarly journals Quantitative genetics of body size evolution on islands: an individual-based simulation approach

2019 ◽  
Vol 15 (10) ◽  
pp. 20190481 ◽  
Author(s):  
José Alexandre F. Diniz-Filho ◽  
Lucas Jardim ◽  
Thiago F. Rangel ◽  
Phillip B. Holden ◽  
Neil R. Edwards ◽  
...  
Keyword(s):  
Body Size ◽  
Quantitative Genetics ◽  
Evolutionary Genetics ◽  
Simulation Approach ◽  
Island Rule ◽  
Size Change ◽  
Evolutionary Patterns ◽  
New Developments ◽  
Size Evolution ◽  
Individual Based Simulation

According to the island rule, small-bodied vertebrates will tend to evolve larger body size on islands, whereas the opposite happens to large-bodied species. This controversial pattern has been studied at the macroecological and biogeographical scales, but new developments in quantitative evolutionary genetics now allow studying the island rule from a mechanistic perspective. Here, we develop a simulation approach based on an individual-based model to model body size change on islands as a progressive adaptation to a moving optimum, determined by density-dependent population dynamics. We applied the model to evaluate body size differentiation in the pigmy extinct hominin Homo floresiensis, showing that dwarfing may have occurred in only about 360 generations (95% CI ranging from 150 to 675 generations). This result agrees with reports suggesting rapid dwarfing of large mammals on islands, as well as with the recent discovery that small-sized hominins lived in Flores as early as 700 kyr ago. Our simulations illustrate the power of analysing ecological and evolutionary patterns from an explicit quantitative genetics perspective.

scholarly journals Fossils and living taxa agree on patterns of body mass evolution: a case study with Afrotheria

2015 ◽  
Vol 282 (1821) ◽  
pp. 20152023 ◽  
Author(s):  
Mark N. Puttick ◽  
Gavin H. Thomas
Keyword(s):  
Body Mass ◽  
Fossil Record ◽  
Morphological Character ◽  
Morphological Evolution ◽  
Evolutionary Model ◽  
The Body ◽  
Evolutionary Patterns ◽  
Size Evolution ◽  
Body Size Evolution

Most of life is extinct, so incorporating some fossil evidence into analyses of macroevolution is typically seen as necessary to understand the diversification of life and patterns of morphological evolution. Here we test the effects of inclusion of fossils in a study of the body size evolution of afrotherian mammals, a clade that includes the elephants, sea cows and elephant shrews. We find that the inclusion of fossil tips has little impact on analyses of body mass evolution; from a small ancestral size (approx. 100 g), there is a shift in rate and an increase in mass leading to the larger-bodied Paenungulata and Tubulidentata, regardless of whether fossils are included or excluded from analyses. For Afrotheria, the inclusion of fossils and morphological character data affect phylogenetic topology, but these differences have little impact upon patterns of body mass evolution and these body mass evolutionary patterns are consistent with the fossil record. The largest differences between our analyses result from the evolutionary model, not the addition of fossils. For some clades, extant-only analyses may be reliable to reconstruct body mass evolution, but the addition of fossils and careful model selection is likely to increase confidence and accuracy of reconstructed macroevolutionary patterns.

Classification of body shape characteristics of women's torsos using angles

2010 ◽  
Vol 22 (4) ◽  
pp. 297-311 ◽  
Author(s):  
Wookyung Lee ◽  
Haruki Imaoka
Keyword(s):  
Body Shape ◽  
Three Dimensional ◽  
The Body ◽  
Data Set ◽  
Content Type ◽  
Body Sizes ◽  
Body Shapes ◽  
Three Body ◽  
Shape Characteristics

PurposeThe purpose of this paper is to classify body shapes using angular defects instead of sizes.Design/methodology/approachA large amount of dimensional data from a national anthropometry survey was analysed, and a basic pattern and its polyhedron were also used to create a three‐dimensional body shape from three body sizes. Using this method, the sizes were converted into nine angular defects.FindingsThe authors could define the factors explaining body shape characteristics and classify the body shapes into four groups. The four groups could be characterised by two pattern making difficulties of the upper and lower parts of the body as well as by two proportions, of waist girth to bust girth and bust girth to back length. Furthermore, depending on the age, the authors could understand body shape by the angle made.Originality/valueUsing a polyhedron model, the angles could be calculated using an enormous existing data set of sizes. An angular defect serves as an index to indicate the degree of difficulty for developing a flat pattern. If an angular defect of the bust is large, it is difficult to make a paper pattern of a bust dart. On the other hand, if an angular defect of the waist is large, it is easy to make a paper pattern of a waist dart. Thus, each body shape could be simultaneously characterized by two difficulty indices and two proportions of sizes.

scholarly journals Environmental and scale-dependent evolutionary trends in the body size of crustaceans

2015 ◽  
Vol 282 (1811) ◽  
pp. 20150440 ◽  
Author(s):  
Adiël A. Klompmaker ◽  
Carrie E. Schweitzer ◽  
Rodney M. Feldmann ◽  
Michał Kowalewski
Keyword(s):  
Body Size ◽  
Ecological Impact ◽  
The Body ◽  
Minimum Size ◽  
Brachyuran Crab ◽  
Species Sorting ◽  
Size Evolution ◽  
Body Sizes

The ecological and physiological significance of body size is well recognized. However, key macroevolutionary questions regarding the dependency of body size trends on the taxonomic scale of analysis and the role of environment in controlling long-term evolution of body size are largely unknown. Here, we evaluate these issues for decapod crustaceans, a group that diversified in the Mesozoic. A compilation of body size data for 792 brachyuran crab and lobster species reveals that their maximum, mean and median body size increased, but no increase in minimum size was observed. This increase is not expressed within lineages, but is rather a product of the appearance and/or diversification of new clades of larger, primarily burrowing to shelter-seeking decapods. This argues against directional selective pressures within lineages. Rather, the trend is a macroevolutionary consequence of species sorting: preferential origination of new decapod clades with intrinsically larger body sizes. Furthermore, body size evolution appears to have been habitat-controlled. In the Cretaceous, reef-associated crabs became markedly smaller than those in other habitats, a pattern that persists today. The long-term increase in body size of crabs and lobsters, coupled with their increased diversity and abundance, suggests that their ecological impact may have increased over evolutionary time.

scholarly journals An Italian dinosaur Lagerstätte reveals the tempo and mode of hadrosauriform body size evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alfio Alessandro Chiarenza ◽  
Matteo Fabbri ◽  
Lorenzo Consorti ◽  
Marco Muscioni ◽  
David C. Evans ◽  
...  
Keyword(s):  
Body Size ◽  
Mediterranean Region ◽  
Type Specimen ◽  
Skeletal Remains ◽  
The Body ◽  
Evolutionary Trend ◽  
Island Rule ◽  
Size Evolution ◽  
North Eastern ◽  
Body Size Evolution

AbstractDuring the latest Cretaceous, the European Archipelago was characterized by highly fragmented landmasses hosting putative dwarfed, insular dinosaurs, claimed as fossil evidence of the “island rule”. The Villaggio del Pescatore quarry (north-eastern Italy) stands as the most informative locality within the palaeo-Mediterranean region and represents the first, multi-individual Konservat-Lagerstätte type dinosaur-bearing locality in Italy. The site is here critically re-evaluated as early Campanian in age, thus preceding the final fragmentation stages of the European Archipelago, including all other European localities preserving hypothesized dwarfed taxa. New skeletal remains allowed osteohistological analyses on the hadrosauroid Tethyshadros insularis indicating subadult features in the type specimen whereas a second, herein newly described, larger individual is likely somatically mature. A phylogenetic comparative framework places the body-size of T. insularis in range with other non-hadrosaurid Eurasian hadrosauroids, rejecting any significant evolutionary trend towards miniaturisation in this clade, confuting its ‘pygmy’ status, and providing unmatched data to infer environmentally-driven body-size trends in Mesozoic dinosaurs.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

scholarly journals Has the Credibility of the Social Sciences Been Credibly Destroyed? Reanalyzing the “Many Analysts, One Data Set” Project

2021 ◽  
Vol 7 ◽  
pp. 237802312110244
Author(s):  
Katrin Auspurg ◽  
Josef Brüderl
Keyword(s):  
Social Sciences ◽  
Causal Reasoning ◽  
Research Question ◽  
Social Science Research ◽  
Science Research ◽  
Skin Tone ◽  
Data Set ◽  
The Social ◽  
The Many ◽  
Definition Of

In 2018, Silberzahn, Uhlmann, Nosek, and colleagues published an article in which 29 teams analyzed the same research question with the same data: Are soccer referees more likely to give red cards to players with dark skin tone than light skin tone? The results obtained by the teams differed extensively. Many concluded from this widely noted exercise that the social sciences are not rigorous enough to provide definitive answers. In this article, we investigate why results diverged so much. We argue that the main reason was an unclear research question: Teams differed in their interpretation of the research question and therefore used diverse research designs and model specifications. We show by reanalyzing the data that with a clear research question, a precise definition of the parameter of interest, and theory-guided causal reasoning, results vary only within a narrow range. The broad conclusion of our reanalysis is that social science research needs to be more precise in its “estimands” to become credible.

scholarly journals Different environmental variables predict body and brain size evolution in Homo

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Manuel Will ◽  
Mario Krapp ◽  
Jay T. Stock ◽  
Andrea Manica
Keyword(s):  
Environmental Factors ◽  
Cognitive Abilities ◽  
Net Primary Productivity ◽  
Brain Size ◽  
Environmental Influence ◽  
Size Variation ◽  
Evolutionary Pattern ◽  
Statistical Framework ◽  
Size Evolution ◽  
Major Predictor

AbstractIncreasing body and brain size constitutes a key macro-evolutionary pattern in the hominin lineage, yet the mechanisms behind these changes remain debated. Hypothesized drivers include environmental, demographic, social, dietary, and technological factors. Here we test the influence of environmental factors on the evolution of body and brain size in the genus Homo over the last one million years using a large fossil dataset combined with global paleoclimatic reconstructions and formalized hypotheses tested in a quantitative statistical framework. We identify temperature as a major predictor of body size variation within Homo, in accordance with Bergmann’s rule. In contrast, net primary productivity of environments and long-term variability in precipitation correlate with brain size but explain low amounts of the observed variation. These associations are likely due to an indirect environmental influence on cognitive abilities and extinction probabilities. Most environmental factors that we test do not correspond with body and brain size evolution, pointing towards complex scenarios which underlie the evolution of key biological characteristics in later Homo.

Tuning of a Basic Coordination Pattern Constructs Straight-Ahead and Curved Walking in Humans

2004 ◽  
Vol 91 (4) ◽  
pp. 1524-1535 ◽  
Author(s):  
Grégoire Courtine ◽  
Marco Schieppati
Keyword(s):  
Principal Components ◽  
Lower Limb ◽  
Time Course ◽  
Body Movement ◽  
The Body ◽  
Whole Body ◽  
Coordination Pattern ◽  
Data Set ◽  
Coordination Patterns ◽  
Straight Ahead

We tested the hypothesis that common principles govern the production of the locomotor patterns for both straight-ahead and curved walking. Whole body movement recordings showed that continuous curved walking implies substantial, limb-specific changes in numerous gait descriptors. Principal component analysis (PCA) was used to uncover the spatiotemporal structure of coordination among lower limb segments. PCA revealed that the same kinematic law accounted for the coordination among lower limb segments during both straight-ahead and curved walking, in both the frontal and sagittal planes: turn-related changes in the complex behavior of the inner and outer limbs were captured in limb-specific adaptive tuning of coordination patterns. PCA was also performed on a data set including all elevation angles of limb segments and trunk, thus encompassing 13 degrees of freedom. The results showed that both straight-ahead and curved walking were low dimensional, given that 3 principal components accounted for more than 90% of data variance. Furthermore, the time course of the principal components was unchanged by curved walking, thereby indicating invariant coordination patterns among all body segments during straight-ahead and curved walking. Nevertheless, limb- and turn-dependent tuning of the coordination patterns encoded the adaptations of the limb kinematics to the actual direction of the walking body. Absence of vision had no significant effect on the intersegmental coordination during either straight-ahead or curved walking. Our findings indicate that kinematic laws, probably emerging from the interaction of spinal neural networks and mechanical oscillators, subserve the production of both straight-ahead and curved walking. During locomotion, the descending command tunes basic spinal networks so as to produce the changes in amplitude and phase relationships of the spinal output, sufficient to achieve the body turn.

Gendered Secularization and the Body Policing of Muslim Women

2018 ◽  
Author(s):  
Raissa Killoran
Keyword(s):  
Muslim Women ◽  
The State ◽  
The Body ◽  
Religious Expression ◽  
Women's Bodies ◽  
Cultural Symbols ◽  
Religious Symbols ◽  
Female Bodies ◽  
The Many ◽  
A Site

The many usages of the term ‘secularism’ have generated an ambiguity in the word; as a political guise, it may be used to engender anti-religious fervor. Particularly in regards to veiling among female Muslim adherents, the attainment of a secular state and touting of the necessity of dismantling religious symbols have functioned as linguistic shields. By calling a “burka ban” necessary or even egalitarian secularization, legislators employ ‘secularization’ as jargon for political ends, enacting a stance of supremacy under the semblance of progress. Secularization has come to function as a political tool - in the name of it, governments may prescribe which cultural symbols are normative and which are of ‘other’ cultures or religious origins. As such, the identification of some religious symbols as foreign and others as normative is a usage of secularization for normalization of dominant religious expression. In this, there is an implicit neocolonialism; by imposing standards of cultural normalcy which are definitively nonMuslim, such policies attempt to divorce Muslims from Islam.  Further, I intend to investigate the gendered aspect of secularization politics. By critiquing clothing and body policing of women, I will demonstrate how secularization projects use the female body and dress as a site for display. By rendering the female physically emblematic of the honor and virtue of an ‘other’ culture, those enacting secularization norms target women’s bodies to act as visual exhibitions of the dominant culture’s hegemony. Here, we see gendered secularization at work - female bodies become controlled by the antireligious zeal of the state, while the state carries out this control on the predicate that it is the religious group enacting unjust control. As such, the policing of female Muslim bodies is symbolic of the policing of Islam as a whole; it acts as an illustration of an imposed, gendered secularization project.

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