scholarly journals Adaptations to light contribute to the ecological niches and evolution of the terrestrial avifauna

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Ian J. Ausprey
Keyword(s):  
Global Change ◽  
Explanatory Power ◽  
Size Variation ◽  
Optical Resolution ◽  
Community Response ◽  
Ecological Niches ◽  
Long Distance ◽  
Eye Morphology ◽  
Eye Size ◽  
Eye Diameter

The role of light in structuring the ecological niche remains a frontier in understanding how vertebrate communities assemble and respond to global change. For birds, eyes represent the primary external anatomical structure specifically evolved to interpret light, yet eye morphology remains understudied compared to movement and dietary traits. Here, I use Stanley Ritland's unpublished measurements of transverse eye diameter from preserved specimens to explore the ecological and phylogenetic drivers of eye morphology for a third of terrestrial avian diversity ( N = 2777 species). Species with larger eyes specialized in darker understory and forested habitats, foraging manoeuvres and prey items requiring long-distance optical resolution and were more likely to occur in tropical latitudes. When compared to dietary and movement traits, eye size was a top predictor for habitat, foraging manoeuvre, diet and latitude, adding 8–28% more explanatory power. Eye size was phylogenetically conserved ( λ = 0.90), with phylogeny explaining 61% of eye size variation. I suggest that light has contributed to the evolution and assembly of global vertebrate communities and that eye size provides a useful predictor to assess community response to global change.

scholarly journals From tree to architecture: how functional morphology of arborescence connects plant biology, evolution and physics

2021 ◽  
Author(s):  
Anita Roth-Nebelsick ◽  
Tatiana Miranda ◽  
Martin Ebner ◽  
Wilfried Konrad ◽  
Christopher Traiser
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Ecological Niches ◽  
Long Distance ◽  
Ongoing Research ◽  
Long Distance Transport ◽  
Theoretical Approaches ◽  
Trade Offs ◽  
Interfacial Physics ◽  
Plant Water Transport

AbstractTrees are the fundamental element of forest ecosystems, made possible by their mechanical qualities and their highly sophisticated conductive tissues. The evolution of trees, and thereby the evolution of forests, were ecologically transformative and affected climate and biogeochemical cycles fundamentally. Trees also offer a substantial amount of ecological niches for other organisms, such as epiphytes, creating a vast amount of habitats. During land plant evolution, a variety of different tree constructions evolved and their constructional principles are a subject of ongoing research. Understanding the “natural construction” of trees benefits strongly from methods and approaches from physics and engineering. Plant water transport is a good example for the ongoing demand for interdisciplinary efforts to unravel form-function relationships on vastly differing scales. Identification of the unique mechanism of water long-distance transport requires a solid basis of interfacial physics and thermodynamics. Studying tree functions by using theoretical approaches is, however, not a one-sided affair: The complex interrelationships between traits, functionality, trade-offs and phylogeny inspire engineers, physicists and architects until today.

scholarly journals Differences in orthodenticle expression promote ommatidial size variation between Drosophila species

2021 ◽  
Author(s):  
Montserrat Torres-Oliva ◽  
Elisa Buchberger ◽  
Alexandra D. Buffry ◽  
Maike Kittelmann ◽  
Lauren Sumner-Rooney ◽  
...  
Keyword(s):  
Natural Variation ◽  
Gene Expression Analysis ◽  
Compound Eye ◽  
Chromosomal Region ◽  
Size Variation ◽  
Compound Eyes ◽  
Positional Candidate ◽  
Eye Size ◽  
Drosophila Mauritiana ◽  
Differential Timing

The compound eyes of insects exhibit extensive variation in ommatidia number and size, which affects how they see and underlies adaptations in their vision to different environments and lifestyles. However, very little is known about the genetic and developmental bases underlying differences in compound eye size. We previously showed that the larger eyes of Drosophila mauritiana compared to D. simulans is caused by differences in ommatidia size rather than number. Furthermore, we identified an X-linked chromosomal region in D. mauritiana that results in larger eyes when introgressed into D. simulans. Here, we used a combination of fine-scale mapping and gene expression analysis to further investigate positional candidate genes on the X chromosome. We found that orthodenticle is expressed earlier in D. mauritiana than in D. simulans during ommatidial maturation in third instar larvae, and we further show that this gene is required for the correct organisation and size of ommatidia in D. melanogaster. Using ATAC-seq, we have identified several candidate eye enhancers of otd as well as potential direct targets of this transcription factor that are differentially expressed between D. mauritiana and D. simulans. Taken together, our results suggest that differential timing of otd expression contributes to natural variation in ommatidia size between D. mauritiana and D. simulans, which provides new insights into the mechanisms underlying the regulation and evolution of compound eye size in insects.

scholarly journals Characterization of the genetic architecture underlying eye size variation within Drosophila melanogaster and Drosophila simulans

2019 ◽  
Author(s):  
Pedro Gaspar ◽  
Saad Arif ◽  
Lauren Sumner-Rooney ◽  
Maike Kittelmann ◽  
Andrew J. Bodey ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Variation ◽  
Size Variation ◽  
Eye Size ◽  
Specific Variation ◽  
Gene Regulatory ◽  
Morphological Differences ◽  
Genomic Regions ◽  
Insect Eye

AbstractThe compound eyes of insects exhibit striking variation in size, reflecting adaptation to different lifestyles and habitats. However, the genetic and developmental bases of variation in insect eye size is poorly understood, which limits our understanding of how these important morphological differences evolve. To address this, we further explored natural variation in eye size within and between four species of the Drosophila melanogaster species subgroup. We found extensive variation in eye size among these species, and flies with larger eyes generally had a shorter inter-ocular distance and vice versa. We then carried out quantitative trait loci (QTL) mapping of intra-specific variation in eye size and inter-ocular distance in both D. melanogaster and D. simulans. This revealed that different genomic regions underlie variation in eye size and inter-ocular distance in both species, which we corroborated by introgression mapping in D. simulans. This suggests that although there is a trade-off between eye size and inter-ocular distance, variation in these two traits is likely to be caused by different genes and so can be genetically decoupled. Finally, although we detected QTL for intra-specific variation in eye size at similar positions in D. melanogaster and D. simulans, we observed differences in eye fate commitment between strains of these two species. This indicates that different developmental mechanisms and therefore, most likely, different genes contribute to eye size variation in these species. Taken together with the results of previous studies, our findings suggest that the gene regulatory network that specifies eye size has evolved at multiple genetic nodes to give rise to natural variation in this trait within and among species.

The evolution of the English street gang

2019 ◽  
Vol 18 (2) ◽  
pp. 64-78 ◽  
Author(s):  
John Pitts
Keyword(s):  
Young People ◽  
Global Change ◽  
Design Methodology ◽  
Relevant Literature ◽  
Explanatory Power ◽  
Global Changes ◽  
Street Gang ◽  
Public Authorities ◽  
Content Type ◽  
Evolutionary Trajectories

Purpose The purpose of this paper is to consider what the author might call the evolution of the evolutionary argument about gangs and, while acknowledging its explanatory power, suggests that gangs may develop in very different ways depending on the available opportunities, pre-existing forms of criminality in the areas in which gangs emerge and global change. Design/methodology/approach It is based on a review of the relevant literature and interviews with purposive samples of research, criminal justice and social welfare professionals and young people involved in or affected by gang crime. Findings were triangulated with data held by the police and other public authorities. Findings The term “street gang” includes a wide variety of groupings all of which are involved in some form of crime but with differential levels of organisation and commitment to purely instrumental goals. Gangs may form but not necessarily evolve. Gangs appear to develop in very different ways depending on the available opportunities, pre-existing forms of criminality in the areas in which they emerge and global changes in drugs markets. Originality/value The originality of the paper consists in its interrogation of the concept of “gang evolution” and its discussion of the variety of forms and evolutionary trajectories of gangs.

scholarly journals Multiple loci linked to inversions are associated with eye size variation in species of the Drosophila virilis phylad

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Micael Reis ◽  
Gordon Wiegleb ◽  
Julien Claude ◽  
Rodrigo Lata ◽  
Britta Horchler ◽  
...  
Keyword(s):  
Size Variation ◽  
Drosophila Virilis ◽  
Eye Size ◽  
Multiple Loci

scholarly journals Biodiversity response to natural gradients of multiple stressors on continental margins

2016 ◽  
Vol 283 (1829) ◽  
pp. 20160637 ◽  
Author(s):  
Erik A. Sperling ◽  
Christina A. Frieder ◽  
Lisa A. Levin
Keyword(s):  
Global Change ◽  
Regional Differences ◽  
Multiple Stressors ◽  
Explanatory Power ◽  
Variance Partitioning ◽  
Continental Margins ◽  
Faunal Change ◽  
Ecological Shifts ◽  
Secondary Stressors ◽  
Sharp Thresholds

Sharp increases in atmospheric CO 2 are resulting in ocean warming, acidification and deoxygenation that threaten marine organisms on continental margins and their ecological functions and resulting ecosystem services. The relative influence of these stressors on biodiversity remains unclear, as well as the threshold levels for change and when secondary stressors become important. One strategy to interpret adaptation potential and predict future faunal change is to examine ecological shifts along natural gradients in the modern ocean. Here, we assess the explanatory power of temperature, oxygen and the carbonate system for macrofaunal diversity and evenness along continental upwelling margins using variance partitioning techniques. Oxygen levels have the strongest explanatory capacity for variation in species diversity. Sharp drops in diversity are seen as O 2 levels decline through the 0.5–0.15 ml l −1 (approx. 22–6 µM; approx. 21–5 matm) range, and as temperature increases through the 7–10°C range. p CO 2 is the best explanatory variable in the Arabian Sea, but explains little of the variance in diversity in the eastern Pacific Ocean. By contrast, very little variation in evenness is explained by these three global change variables. The identification of sharp thresholds in ecological response are used here to predict areas of the seafloor where diversity is most at risk to future marine global change, noting that the existence of clear regional differences cautions against applying global thresholds.

scholarly journals Can functional traits predict plant community response to global change?

Ecosphere ◽  
2016 ◽  
Vol 7 (12) ◽  
Author(s):  
Sarah Kimball ◽  
Jennifer L. Funk ◽  
Marko J. Spasojevic ◽  
Katharine N. Suding ◽  
Scot Parker ◽  
...  
Keyword(s):  
Global Change ◽  
Plant Community ◽  
Functional Traits ◽  
Community Response

scholarly journals Ecophysiology of avian migration in the face of current global hazards

2012 ◽  
Vol 367 (1596) ◽  
pp. 1719-1732 ◽  
Author(s):  
Marcel Klaassen ◽  
Bethany J. Hoye ◽  
Bart A. Nolet ◽  
William A. Buttemer
Keyword(s):  
Global Change ◽  
Migratory Birds ◽  
High Energy ◽  
Change Processes ◽  
Negative Consequences ◽  
Long Distance ◽  
Physiological Limits ◽  
The Face ◽  
Abiotic And Biotic Factors ◽  
The Impact

Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds.

Eye size variation reflects habitat and daily activity patterns in colubrid snakes

2012 ◽  
Vol 273 (8) ◽  
pp. 883-893 ◽  
Author(s):  
Yang Liu ◽  
Li Ding ◽  
Juan Lei ◽  
Ermi Zhao ◽  
Yezhong Tang
Keyword(s):  
Daily Activity ◽  
Activity Patterns ◽  
Size Variation ◽  
Eye Size ◽  
Daily Activity Patterns

scholarly journals Microbial community response to a decade of simulated global changes depends on the plant community

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarai S. Finks ◽  
Claudia Weihe ◽  
Sarah Kimball ◽  
Steven D. Allison ◽  
Adam C. Martiny ◽  
...  
Keyword(s):  
Global Change ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Bacterial Community Composition ◽  
Community Response ◽  
Plant Litter ◽  
Global Changes ◽  
Dependent Manner ◽  
Microbial Composition

Global changes such as increased drought and atmospheric nitrogen deposition perturb both the microbial and plant communities that mediate terrestrial ecosystem functioning. However, few studies consider how microbial responses to global changes may be influenced by interactions with plant communities. To begin to address the role of microbial–plant interactions, we tested the hypothesis that the response of microbial communities to global change depends on the plant community. We characterized bacterial and fungal communities from 395 plant litter samples taken from the Loma Ridge Global Change Experiment, a decade-long global change experiment in Southern California that manipulates rainfall and nitrogen levels across two adjacent ecosystems, a grassland and a coastal sage scrubland. The differences in bacterial and fungal composition between ecosystems paralleled distinctions in plant community composition. In addition to the direct main effects, the global change treatments altered microbial composition in an ecosystem-dependent manner, in support of our hypothesis. The interaction between the drought treatment and ecosystem explained nearly 5% of the variation in bacterial community composition, similar to the variation explained by the ecosystem-independent effects of drought. Unexpectedly, we found that the main effect of drought was approximately four times as strong on bacterial composition as that of nitrogen addition, which did not alter fungal or plant composition. Overall, the findings underscore the importance of considering plant–microbe interactions when considering the transferability of the results of global change experiments across ecosystems.

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