scholarly journals Patterns of morphological diversification in the Ramphastoidea reveal the dramatic divergence of toucans from a conserved morphotype

2021 ◽  
Author(s):  
Krishnapriya Tamma ◽  
Anand Krishnan ◽  
Sushma Reddy

Morphological traits offer insights into an organism s ecological niche, species interactions, and patterns of community organisation. Pantropical lineages - animals and plants distributed across the three tropical continental regions of Asia, Africa, and America - provide a way to test how different environments and communities influence morphological diversification. Here, we examined a monophyletic group of frugivorous birds, the barbets and toucans (Ramphastoidea), which diversified independently on three continents, to investigate whether clades in each region exhibit similar (phylogenetically constrained) or distinct (ecologically influenced) patterns of morphological diversification. Our results show that despite differences in community dynamics in these regions, lineage accumulation patterns through time on all three continents are broadly similar, putatively due to phylogenetic niche conservatism. We quantified morphological variation in light of phylogenetic relatedness to further reveal that all barbet lineages across continents occupy a conserved region of morphospace after correcting for variation in size. However, in the Neotropics, one lineage, the toucans, have diverged dramatically from typical barbet space and converged toward (yet are distinct from) the trait space occupied by the distantly related hornbills in Asia and Africa. Additionally, we found no link between climatic variables and morphological traits. We conclude that barbets exhibit a conserved morphotype across continents and have diversified by scaling mainly in body size. However, the absence of other large frugivorous birds may have allowed toucans to diversify into a different region of morphospace of increased bill/wing to tail/wing ratios. By examining different continental lineages of a single monophyletic bird group, we shed light on the contrasting effects of regional ecological factors and phylogenetic constraints on morphological diversification.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.


2019 ◽  
Vol 28 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Tomas Roslin ◽  
Michael Traugott ◽  
Mattias Jonsson ◽  
Graham N. Stone ◽  
Simon Creer ◽  
...  

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Nicole A Scavo ◽  
Roberto Barrera ◽  
Limarie J Reyes-Torres ◽  
Donald A Yee

Abstract Mosquito community dynamics in urban areas are influenced by an array of both social and ecological factors. Human socioeconomic factors (SEF) can be related to mosquito abundance and diversity as urban mosquito development sites are modified by varying human activity, e.g., level of abandoned structures or amount of accumulated trash. The goal of this study was to investigate the relationships among mosquito diversity, populations of Aedes aegypti, and SEF in a tropical urban setting. Mosquitoes were collected using BG Sentinel 2 traps and CDC light traps during three periods between late 2018 and early 2019 in San Juan, Puerto Rico, and were identified to species. SEFs (i.e. median household income, population density, college-level educational attainment, unemployment, health insurance coverage, percentage of households below the poverty line, amount of trash and level of abandoned homes) were measured using foot surveys and U.S. Census data. We found 19 species with the two most abundant species being Culex quinquefasciatus (n = 10 641, 87.6%) and Ae. aegypti (n = 1558, 12.8%). We found a positive association between Ae. aegypti abundance and mosquito diversity, which were both negatively related to SES and ecological factors. Specifically, lower socioeconomic status neighborhoods had both more Ae. aegypti and more diverse communities, due to more favorable development habitat, indicating that control efforts should be focused in these areas.


2020 ◽  
Vol 117 (37) ◽  
pp. 22858-22865 ◽  
Author(s):  
Vigdis Vandvik ◽  
Olav Skarpaas ◽  
Kari Klanderud ◽  
Richard J. Telford ◽  
Aud H. Halbritter ◽  
...  

Generality in understanding biodiversity responses to climate change has been hampered by substantial variation in the rates and even directions of response to a given change in climate. We propose that such context dependencies can be clarified by rescaling climate gradients in terms of the underlying biological processes, with biotic interactions as a particularly important process. We tested this rescaling approach in a replicated field experiment where entire montane grassland communities were transplanted in the direction of expected temperature and/or precipitation change. In line with earlier work, we found considerable variation across sites in community dynamics in response to climate change. However, these complex context dependencies could be substantially reduced or eliminated by rescaling climate drivers in terms of proxies of plant−plant interactions. Specifically, bryophytes limited colonization by new species into local communities, whereas the cover of those colonists, along with bryophytes, were the primary drivers of local extinctions. These specific interactions are relatively understudied, suggesting important directions for future work in similar systems. More generally, the success of our approach in explaining and simplifying landscape-level variation in climate change responses suggests that developing and testing proxies for relevant underlying processes could be a fruitful direction for building more general models of biodiversity response to climate change.


2020 ◽  
Vol 82 (11) ◽  
Author(s):  
Sten Madec ◽  
Erida Gjini

AbstractMulti-type infection processes are ubiquitous in ecology, epidemiology and social systems, but remain hard to analyze and to understand on a fundamental level. Here, we study a multi-strain susceptible-infected-susceptible model with coinfection. A host already colonized by one strain can become more or less vulnerable to co-colonization by a second strain, as a result of facilitating or competitive interactions between the two. Fitness differences between N strains are mediated through $$N^2$$ N 2 altered susceptibilities to secondary infection that depend on colonizer-cocolonizer identities ($$K_{ij}$$ K ij ). By assuming strain similarity in such pairwise traits, we derive a model reduction for the endemic system using separation of timescales. This ‘quasi-neutrality’ in trait space sets a fast timescale where all strains interact neutrally, and a slow timescale where selective dynamics unfold. We find that these slow dynamics are governed by the replicator equation for N strains. Our framework allows to build the community dynamics bottom-up from only pairwise invasion fitnesses between members. We highlight that mean fitness of the multi-strain network, changes with their individual dynamics, acts equally upon each type, and is a key indicator of system resistance to invasion. By uncovering the link between N-strain epidemiological coexistence and the replicator equation, we show that the ecology of co-colonization relates to Fisher’s fundamental theorem and to Lotka-Volterra systems. Besides efficient computation and complexity reduction for any system size, these results open new perspectives into high-dimensional community ecology, detection of species interactions, and evolution of biodiversity.


2018 ◽  
Vol 191 (4) ◽  
pp. 421-434 ◽  
Author(s):  
Marco Túlio P. Coelho ◽  
Thiago F. Rangel

2020 ◽  
Vol 287 (1918) ◽  
pp. 20192211 ◽  
Author(s):  
Annika Schirmer ◽  
Julia Hoffmann ◽  
Jana A. Eccard ◽  
Melanie Dammhahn

Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species ( Myodes glareolus , Apodemus agrarius ). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture–mark–recapture ( n = 126) and automated VHF telemetry ( n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity.


2013 ◽  
Vol 368 (1624) ◽  
pp. 20120477 ◽  
Author(s):  
Eric Post ◽  
Toke T. Høye

Despite uncertainties related to sustained funding, ideological rivalries and the turnover of research personnel, long-term studies and studies espousing a long-term perspective in ecology have a history of contributing landmark insights into fundamental topics, such as population- and community dynamics, species interactions and ecosystem function. They also have the potential to reveal surprises related to unforeseen events and non-stationary dynamics that unfold over the course of ongoing observation and experimentation. The unprecedented rate and magnitude of current and expected abiotic changes in tundra environments calls for a synthetic overview of the scope of ecological responses these changes have elicited. In this special issue, we present a series of contributions that advance the long view of ecological change in tundra systems, either through sustained long-term research, or through retrospective or prospective modelling. Beyond highlighting the value of long-term research in tundra systems, the insights derived herein should also find application to the study of ecological responses to environmental change in other biomes as well.


2016 ◽  
Vol 113 (29) ◽  
pp. 7986-7993 ◽  
Author(s):  
Kerry L. Shaw ◽  
Rosemary G. Gillespie

Remote island archipelagos offer superb opportunities to study the evolution of community assembly because of their relatively young and simple communities where speciation contributes to the origin and evolution of community structure. There is great potential for common phylogeographic patterns among remote archipelagos that originate through hotspot volcanism, particularly when the islands formed are spatially isolated and linearly arranged. The progression rule is characterized by a phylogeographic concordance between island age and lineage age in a species radiation. Progression is most likely to arise when a species radiation begins on an older island before the emergence of younger islands of a hotspot archipelago. In the simplest form of progression, colonization of younger islands as they emerge and offer appropriate habitat, is coincident with cladogenesis. In this paper, we review recent discoveries of the progression rule on seven hotspot archipelagos. We then discuss advantages that progression offers to the study of community assembly, and insights that community dynamics may offer toward understanding the evolution of progression. We describe results from two compelling cases of progression where the mosaic genome may offer insights into contrasting demographic histories that shed light on mechanisms of speciation and progression on remote archipelagos.


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