Hominins are a single lineage: brain and body size variability does not reflect postulated taxonomic diversity of hominins

HOMO ◽  
2004 ◽  
Vol 55 (1-2) ◽  
pp. 21-37 ◽  
Author(s):  
M. Henneberg ◽  
C. de Miguel
Keyword(s):  
Body Size ◽  
Taxonomic Diversity ◽  
Size Variability

scholarly journals Effect of changes in the fractal structure of a littoral zone in the course of lake succession on the abundance, body size sequence and biomass of beetles

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5662
Author(s):  
Joanna Pakulnicka ◽  
Andrzej Zawal
Keyword(s):  
Fractal Dimension ◽  
Body Size ◽  
Fractal Structure ◽  
Lake Management ◽  
Open Water ◽  
Taxonomic Diversity ◽  
The Body ◽  
Water Beetles ◽  
Water Surface Area ◽  
Depth Analysis

Dystrophic lakes undergo natural disharmonic succession, in the course of which an increasingly complex and diverse, mosaic-like pattern of habitats evolves. In the final seral stage, the most important role is played by a spreading Sphagnum mat, which gradually reduces the lake’s open water surface area. Long-term transformations in the primary structure of lakes cause changes in the structure of lake-dwelling fauna assemblages. Knowledge of the succession mechanisms in lake fauna is essential for proper lake management. The use of fractal concepts helps to explain the character of fauna in relation to other aspects of the changing complexity of habitats. Our 12-year-long study into the succession of water beetles has covered habitats of 40 selected lakes which are diverse in terms of the fractal dimension. The taxonomic diversity and density of lake beetles increase parallel to an increase in the fractal dimension. An in-depth analysis of the fractal structure proved to be helpful in explaining the directional changes in fauna induced by the natural succession of lakes. Negative correlations appear between the body size and abundance. An increase in the density of beetles within the higher dimension fractals is counterbalanced by a change in the size of individual organisms. As a result, the biomass is constant, regardless of the fractal dimension.

scholarly journals The evolution of body size in termites

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Thomas Bourguignon
Keyword(s):  
Body Size ◽  
Size Reduction ◽  
Head Width ◽  
Termite Species ◽  
Fossil Species ◽  
Modern Species ◽  
Size Evolution ◽  
Phylogenetic Framework ◽  
Size Variability ◽  
Width Measurements

Termites are social cockroaches. Because non-termite cockroaches are larger than basal termite lineages, which themselves include large termite species, it has been proposed that termites experienced a unidirectional body size reduction since they evolved eusociality. However, the validity of this hypothesis remains untested in a phylogenetic framework. Here, we reconstructed termite body size evolution using head width measurements of 1638 modern and fossil termite species. We found that the unidirectional body size reduction model was only supported by analyses excluding fossil species. Analyses including fossil species suggested that body size diversified along with speciation events and estimated that the size of the common ancestor of modern termites was comparable to that of modern species. Our analyses further revealed that body size variability among species, but not body size reduction, is associated with features attributed to advanced termite societies. Our results suggest that miniaturization took place at the origin of termites, while subsequent complexification of termite societies did not lead to further body size reduction.

New smallest specimen of the pterosaurPteranodonand ontogenetic niches in pterosaurs

2017 ◽  
Vol 92 (2) ◽  
pp. 254-271 ◽  
Author(s):  
S. Christopher Bennett
Keyword(s):  
Body Size ◽  
Parental Care ◽  
Large Body ◽  
Taxonomic Diversity ◽  
Ecological Niches ◽  
Adult Size ◽  
Niobrara Formation ◽  
Large Body Size ◽  
Juvenile Specimen

AbstractA new juvenile specimen ofPteranodonfrom the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation ofPteranodonas growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thusPteranodonexhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g.,Rhamphorhynchus,Pterodactylus,Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians.

scholarly journals Metabolic dominance of bivalves predates brachiopod diversity decline by more than 150 million years

2014 ◽  
Vol 281 (1783) ◽  
pp. 20133122 ◽  
Author(s):  
Jonathan L. Payne ◽  
Noel A. Heim ◽  
Matthew L. Knope ◽  
Craig R. McClain
Keyword(s):  
Body Size ◽  
Metabolic Activity ◽  
Energy Use ◽  
Taxonomic Diversity ◽  
Metabolic Rates ◽  
Geological Time ◽  
Numerical Abundance ◽  
Ecological Importance ◽  
Ecological Dominance ◽  
Size Data

Brachiopods and bivalves feed in similar ways and have occupied the same environments through geological time, but brachiopods were far more diverse and abundant in the Palaeozoic whereas bivalves dominate the post-Palaeozoic, suggesting a transition in ecological dominance 250 Ma. However, diversity and abundance data alone may not adequately describe key changes in ecosystem function, such as metabolic activity. Here, we use newly compiled body size data for 6066 genera of bivalves and brachiopods to calculate metabolic rates and revisit this question from the perspective of energy use, finding that bivalves already accounted for a larger share of metabolic activity in Palaeozoic oceans. We also find that the metabolic activity of bivalves has increased by more than two orders of magnitude over this interval, whereas brachiopod metabolic activity has declined by more than 50%. Consequently, the increase in bivalve energy metabolism must have occurred via the acquisition of new food resources rather than through the displacement of brachiopods. The canonical view of a mid-Phanerozoic transition from brachiopod to bivalve dominance results from a focus on taxonomic diversity and numerical abundance as measures of ecological importance. From a metabolic perspective, the oceans have always belonged to the clams.

scholarly journals A global analysis of cladoceran body size and its variation linking to habitat, distribution and taxonomy

2019 ◽  
Vol 187 (4) ◽  
pp. 1119-1130 ◽  
Author(s):  
Eric Zeus Rizo ◽  
Shaolin Xu ◽  
Quehui Tang ◽  
Rey Donne S Papa ◽  
Henri J Dumont ◽  
...  
Keyword(s):  
Body Size ◽  
Large Scale ◽  
Global Analysis ◽  
Functional Trait ◽  
Categorical Variables ◽  
Extensive Literature ◽  
Frequency Distributions ◽  
Size Frequency ◽  
Size Variability ◽  
Taxonomic Affiliation

Abstract Body size is a functional trait that influences the overall biology and ecology of an organism. Studying the shape of size–frequency distributions and size variability within different scales, approximates the influence of large-scale ecological and evolutionary processes on a species. In this study we examine the patterns of distribution and variability of body size among freshwater Cladocera across different taxonomic levels, geographic distribution and habitat association. Using extensive literature data, we show the global distribution of body size in freshwater Cladocera. Hierarchical models were used to assess the effect of different categorical variables on size variability. Our results show that almost all size–frequency distributions were skewed right in all categories. The hierarchical model showed that taxonomic affiliation contributes the most to size variability in our dataset, suggesting that size might be a conserved trait. Large genera (≥1mm) have larger estimated variability compared to smaller genera. In general, our observations on size–frequency distributions and size variability show a brief insight in the varying advantages of adaptive body size in this group of organisms in both biology (physiology) and ecology (competition and co-existence). Thus, body size is a trait important to the survival and continuing evolution of Cladocera.

Intraspecific body size variability in soil organisms at a European scale: Implications for functional biogeography

2018 ◽  
Vol 32 (11) ◽  
pp. 2562-2570 ◽  
Author(s):  
Jonathan Bonfanti ◽  
Mickaël Hedde ◽  
Sophie Joimel ◽  
Paul Henning Krogh ◽  
Cyrille Violle ◽  
...  
Keyword(s):  
Body Size ◽  
Soil Organisms ◽  
Size Variability
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