scholarly journals No Evidence for Effects of Ecological and Behavioral Factors on Eye Size Evolution in Anurans

2021 ◽  
Vol 9 ◽  
Author(s):  
Chuan Chen ◽  
Ying Jiang ◽  
Long Jin ◽  
Wen Bo Liao
Keyword(s):  
Mating System ◽  
Light Availability ◽  
Habitat Type ◽  
Behavioral Factors ◽  
Activity Time ◽  
Defensive Strategy ◽  
Selective Pressures ◽  
Eye Size ◽  
Size Evolution ◽  
Size Scales

Eye size varies markedly among taxonomic levels, and this variation is often related to the patterns shaped by phylogeny and ecological and behavioral factors. The selective pressures underlying eye size evolution are especially studied in fishes, anurans, birds, and mammals. However, selective pressures underlying the eye size evolution in anurans have inconsistent scaling rules. Here, we investigated the links between eye size and both ecological (e.g., light availability and habitat type) and behavioral factors (e.g., activity time, foraging mobility, defensive strategy, and mating system) among 252 species of anurans by using phylogenetically controlled generalized least-squared (PGLS) regression. Results show that anuran eye size scales hypo-allometrically with body size. However, eye size was not significantly influenced by ecological and behavioral factors, including habitat type, activity time, light availability, foraging mobility, defensive strategy, and mating system. Therefore, neither ecology nor behavior plays a key role in promoting eye size evolution in frogs.

Copulation calls in wild Mueller’s gibbons (Hylobates muelleri)

2019 ◽  
Vol 20 (2) ◽  
pp. 362-374
Author(s):  
Yoichi Inoue ◽  
Waidi Sinun ◽  
Kazuo Okanoya
Keyword(s):  
Mating System ◽  
Social Organization ◽  
Sperm Competition ◽  
Mate Guarding ◽  
Conservation Area ◽  
Mating Activity ◽  
Selective Pressures ◽  
Female Promiscuity ◽  
Vocal Signals ◽  
The Relationship

Abstract Mating activity of a wild Mueller’s gibbon group (Hylobates muelleri) was observed in the Danum Valley Conservation Area, Sabah, Malaysia. The purpose of this study was to investigate the function of copulation calls in gibbons. The female emitted copulation calls at the time of intromission and pelvic thrusting. Copulation calls were composed of two notes and one of them was sung only while mating. Approximately half of copulation calls were sung near the range boundary. Mating with copulation calls sometimes occurred while singing. According to the model that female copulation calls have evolved under the selective pressures of risk of infanticide and sperm competition, copulation calls should be rare in species with little female promiscuity. As gibbons usually live in pair-living social organization and have a monogamous mating system, no vocal signals by female gibbons are considered to be needed. However, clear copulation calls were emitted by the female. It suggests that the relationship between paired gibbons is unstable. Copulation calls by the female Mueller’s gibbon may function to increase mate guarding and strengthen the pair bond.

Investigating the role of body size, ecology, and behavior in anuran eye size evolution

2019 ◽  
Vol 33 (4) ◽  
pp. 585-598 ◽  
Author(s):  
Chun Hua Huang ◽  
Mao Jun Zhong ◽  
Wen Bo Liao ◽  
Alexander Kotrschal
Keyword(s):  
Body Size ◽  
Eye Size ◽  
Size Evolution ◽  
And Behavior

scholarly journals Evolution of C4 photosynthesis predicted by constraint-based modelling

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Mary-Ann Blätke ◽  
Andrea Bräutigam
Keyword(s):  
Ground State ◽  
C4 Photosynthesis ◽  
Selective Pressure ◽  
Light Availability ◽  
Resource Limitation ◽  
Optimal Solutions ◽  
Leaf Architecture ◽  
Selective Pressures ◽  
C3 Photosynthesis ◽  
Evolutionary Trajectories

Constraint-based modelling (CBM) is a powerful tool for the analysis of evolutionary trajectories. Evolution, especially evolution in the distant past, is not easily accessible to laboratory experimentation. Modelling can provide a window into evolutionary processes by allowing the examination of selective pressures which lead to particular optimal solutions in the model. To study the evolution of C4 photosynthesis from a ground state of C3 photosynthesis, we initially construct a C3 model. After duplication into two cells to reflect typical C4 leaf architecture, we allow the model to predict the optimal metabolic solution under various conditions. The model thus identifies resource limitation in conjunction with high photorespiratory flux as a selective pressure relevant to the evolution of C4. It also predicts that light availability and distribution play a role in guiding the evolutionary choice of possible decarboxylation enzymes. The data shows evolutionary CBM in eukaryotes predicts molecular evolution with precision.

scholarly journals Periphyton Function in Lake Ecosystems

2002 ◽  
Vol 2 ◽  
pp. 1449-1468 ◽  
Author(s):  
Yvonne Vadeboncoeur ◽  
Alan D. Steinman
Keyword(s):  
Light Availability ◽  
Habitat Type ◽  
High Water ◽  
Nutrient Cycles ◽  
Lake Morphometry ◽  
Trophic Conditions ◽  
Lake Ecosystems ◽  
Food Web Interactions ◽  
Spatial Hierarchy

Periphyton communities have received relatively little attention in lake ecosystems. However, evidence is increasing that they play a key role in primary productivity, nutrient cycling, and food web interactions. This review summarizes those findings and places them in a conceptual framework to evaluate the functional importance of periphyton in lakes. The role of periphyton is conceptualized based on a spatial hierarchy. At the coarsest scale, landscape properties such as lake morphometry, influence the amount of available habitat for periphyton growth. Watershed-related properties, such as loading of dissolved organic matter, nutrients, and sediments influence light availability and hence periphyton productivity. At the finer scale of within the lake, both habitat availability and habitat type affect periphyton growth and abundance. In addition, periphyton and phytoplankton compete for available resources at the within-lake scale. Our review indicates that periphyton plays an important functional role in lake nutrient cycles and food webs, especially under such conditions as relatively shallow depths, nutrient-poor conditions, or high water-column transparency. We recommend more studies assessing periphyton function across a spectrum of lake morphometry and trophic conditions.

Does nocturnal activity prolong gecko longevity?

2020 ◽  
Vol 66 (3-4) ◽  
pp. 231-238
Author(s):  
Gavin Stark ◽  
Rachel Schwarz ◽  
Shai Meiri
Keyword(s):  
Uv Radiation ◽  
Metabolic Rates ◽  
Activity Time ◽  
Temperature Dependent ◽  
Lizard Species ◽  
Selective Pressures ◽  
Metabolic Costs ◽  
Major Taxon ◽  
Intrinsic Mortality ◽  
Diurnal Species

The majority of lizard clades are ancestrally and predominantly diurnal. The only major taxon in which most species are nocturnal is the Gekkota (geckos and pygopodids). As ectothermic thermoregulators, lizard metabolic rates are highly temperature dependent, and diurnal lizards therefore demonstrate higher metabolic rates than nocturnal ones. Furthermore, exposure to solar radiation is thought to reduce ectothermic longevity by increasing both metabolic costs and the rate of accumulating harmful mutations through UV radiation (UVC specifically). In being nocturnal, ectothermic species may reduce their intrinsic mortality rates and thus live longer. To test this hypothesis, we collected literature data on the maximum longevities of 740 lizard species, of which 185 are geckos. We examined whether geckos live longer than other lizards, and whether activity time affects gecko longevity. While geckos live relatively long for lizards of their size, their activity time was found to be unrelated to longevity, contradicting our predictions. We suggest that diurnal species may have evolved higher resistance to UV radiation via thicker, more keratinized skin. Elevated metabolic rates do not automatically equate with faster aging. Mortality through extrinsic causes (e.g., predation) may impose much stronger selective pressures than intrinsic causes.

scholarly journals Genome size evolution: towards new model systems for old questions

2020 ◽  
Vol 287 (1933) ◽  
pp. 20201441
Author(s):  
Julie Blommaert
Keyword(s):  
Genome Size ◽  
New Technologies ◽  
Model Systems ◽  
Selective Pressures ◽  
Sequencing Technologies ◽  
Open Questions ◽  
Genome Size Evolution ◽  
Size Evolution ◽  
Contradictory Evidence

Genome size (GS) variation is a fundamental biological characteristic; however, its evolutionary causes and consequences are the topic of ongoing debate. Whether GS is a neutral trait or one subject to selective pressures, and how strong these selective pressures are, may remain open questions. Fundamentally, the genomic sequences responsible for this variation directly impact the potential evolutionary outcomes and, equally, are the targets of different evolutionary pressures. For example, duplications and deletions of genic regions (large or small) can have immediate and drastic phenotypic effects, while an expansion or contraction of non-coding DNA is less likely to cause catastrophic phenotypic effects. However, in the long term, the accumulation or deletion of ncDNA is likely to have larger effects. Modern sequencing technologies are allowing for the dissection of these proximate causes, but a combination of these new technologies with more traditional evolutionary experiments and approaches could revolutionize this debate and potentially resolve many of these arguments. Here, I discuss an ambitious way forward for GS research, putting it in context of historical debates, theories and sometimes contradictory evidence, and highlighting the promise of combining new sequencing technologies and analytical developments with more traditional experimental evolution approaches.

scholarly journals Trait evolution is reversible, repeatable, and decoupled in the soldier caste of turtle ants

2020 ◽  
Vol 117 (12) ◽  
pp. 6608-6615 ◽  
Author(s):  
Scott Powell ◽  
Shauna L. Price ◽  
Daniel J. C. Kronauer
Keyword(s):  
Functional Traits ◽  
Model Fitting ◽  
Species Level ◽  
Head Size ◽  
Phenotypic Change ◽  
Multiple Model ◽  
Defensive Strategy ◽  
Caste Evolution ◽  
Size Evolution ◽  
Gains And Losses

The scope of adaptive phenotypic change within a lineage is shaped by how functional traits evolve. Castes are defining functional traits of adaptive phenotypic change in complex insect societies, and caste evolution is expected to be phylogenetically conserved and developmentally constrained at broad phylogenetic scales. Yet how castes evolve at the species level has remained largely unaddressed. Turtle ant soldiers (genusCephalotes), an iconic example of caste specialization, defend nest entrances by using their elaborately armored heads as living barricades. Across species, soldier morphotype determines entrance specialization and defensive strategy, while head size sets the specific size of defended entrances. Our species-level comparative analyses of morphotype and head size evolution reveal that these key ecomorphological traits are extensively reversible, repeatable, and decoupled within soldiers and between soldier and queen castes. Repeated evolutionary gains and losses of the four morphotypes were reconstructed consistently across multiple analyses. In addition, morphotype did not predict mean head size across the three most common morphotypes, and head size distributions overlapped broadly across all morphotypes. Concordantly, multiple model-fitting approaches suggested that soldier head size evolution is best explained by a process of divergent pulses of change. Finally, while soldier and queen head size were broadly coupled across species, the level of head size disparity between castes was decoupled from both queen head size and soldier morphotype. These findings demonstrate that caste evolution can be highly dynamic at the species level, reshaping our understanding of adaptive morphological change in complex social lineages.

scholarly journals An atypical mating system in a neotropical manakin

2020 ◽  
Vol 7 (1) ◽  
pp. 191548 ◽  
Author(s):  
Milene G. Gaiotti ◽  
Michael S. Webster ◽  
Regina H. Macedo
Keyword(s):  
Sexual Selection ◽  
Mating System ◽  
Mating Systems ◽  
Evolutionary Development ◽  
Selective Pressures ◽  
Exclusive Territories ◽  
Monogamous Species ◽  
Socially Monogamous ◽  
Mixed Paternity ◽  
Close Relatives

Most of the diversity in the mating systems of birds and other animals comes at higher taxonomic levels, such as across orders. Although divergent selective pressures should lead to animal mating systems that diverge sharply from those of close relatives, opportunities to examine the importance of such processes are scarce. We addressed this issue using the Araripe manakin ( Antilophia bokermanni ), a species endemic to a forest enclave surrounded by xeric shrublands in Brazil. Most manakins exhibit polygynous lekking mating systems that lack territoriality but exhibit strong sexual selection. In sharp contrast, we found that male Araripe manakins defended exclusive territories, and females nested within male territories. However, territoriality and offspring paternity were dissociated: males sired only 7% of nestlings from the nests within their territories and non-territorial males sired numerous nestlings. Moreover, female polyandry was widespread, with most broods exhibiting mixed paternity. Apparently, territories in this species function differently from both lekking arenas and resource-based territories of socially monogamous species. The unexpected territoriality of Araripe manakins and its dissociation from paternity is a unique evolutionary development within the manakin clade. Collectively, our findings underscore how divergences in mating systems might evolve based on selective pressures from novel environmental contexts.

scholarly journals Evolution of C4 photosynthesis predicted by constraint-based modelling

2019 ◽  
Author(s):  
Mary-Ann Blätke ◽  
Andrea Bräutigam
Keyword(s):  
Ground State ◽  
C4 Photosynthesis ◽  
Selective Pressure ◽  
Light Availability ◽  
Resource Limitation ◽  
Optimal Solutions ◽  
Leaf Architecture ◽  
Selective Pressures ◽  
C3 Photosynthesis ◽  
Evolutionary Trajectories

AbstractConstraint-based modelling (CBM) is a powerful tool for the analysis of evolutionary trajectories. Evolution, especially evolution in the distant past, is not easily accessible to laboratory experimentation. Modelling can provide a window into evolutionary processes by allowing the examination of selective pressures which lead to particular optimal solutions in the model. To study the evolution of C4 photosynthesis from a ground state of C3 photosynthesis, we initially construct a C3 model. After duplication into two cells to reflect typical C4 leaf architecture, we allow the model to predict the optimal metabolic solution under various conditions. The model thus identifies resource limitation in conjunction with high photorespiratory flux as a selective pressure relevant to the evolution of C4. It also predicts that light availability and distribution play a role in guiding the evolutionary choice of possible decarboxylation enzymes. The data shows evolutionary CBM in eukaryotes predicts molecular evolution with precision.

The influence of domestication, insularity and sociality on the tempo and mode of brain size evolution in mammals

2020 ◽  
Vol 132 (1) ◽  
pp. 221-231
Author(s):  
Silvia Castiglione ◽  
Carmela Serio ◽  
Martina Piccolo ◽  
Alessandro Mondanaro ◽  
Marina Melchionna ◽  
...  
Keyword(s):  
Brain Size ◽  
Comparative Method ◽  
Similar Reasoning ◽  
Domestic Species ◽  
Selective Pressures ◽  
Size Evolution ◽  
Large Brain ◽  
Taxon Tree ◽  
Selective Forces ◽  
The Common

Abstract The ability to develop complex social bonds and an increased capacity for behavioural flexibility in novel environments have both been forwarded as selective forces favouring the evolution of a large brain in mammals. However, large brains are energetically expensive, and in circumstances in which selective pressures are relaxed, e.g. on islands, smaller brains are selected for. Similar reasoning has been offered to explain the reduction of brain size in domestic species relative to their wild relatives. Herein, we assess the effect of domestication, insularity and sociality on brain size evolution at the macroevolutionary scale. Our results are based on analyses of a 426-taxon tree, including both wild species and domestic breeds. We further develop the phylogenetic ridge regression comparative method (RRphylo) to work with discrete variables and compare the rates (tempo) and direction (mode) of brain size evolution among categories within each of three factors (sociality, insularity and domestication). The common assertion that domestication increases the rate of brain size evolution holds true. The same does not apply to insularity. We also find support for the suggested but previously untested hypothesis that species living in medium-sized groups exhibit faster rates of brain size evolution than either solitary or herding taxa.

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