scholarly journals Character displacement drives trait divergence in a continental fauna

2021 ◽  
Vol 118 (20) ◽  
pp. e2021209118
Author(s):  
Sean A. S. Anderson ◽  
Jason T. Weir
Keyword(s):  
Evolutionary Theory ◽  
Species Interactions ◽  
New World ◽  
Latitudinal Gradient ◽  
Character Displacement ◽  
Sympatric Species ◽  
Closely Related Species ◽  
Species Sorting ◽  
Trait Divergence ◽  
The Tropics

Coexisting (sympatric) pairs of closely related species are often characterized by exaggerated trait differences. This widespread pattern is consistent with adaptation for reduced similarity due to costly interactions (i.e., “character displacement”)—a classic hypothesis in evolutionary theory. But it is equally consistent with a community assembly bias in which lineages with greater trait differences are more likely to establish overlapping ranges in the first place (i.e., “species sorting”), as well as with null expectations of trait divergence through time. Few comparative analyses have explicitly modeled these alternatives, and it remains unclear whether trait divergence is a general prerequisite for sympatry or a consequence of interactions between sympatric species. Here, we develop statistical models that allow us to distinguish the signature of these processes based on patterns of trait divergence in closely related lineage pairs. We compare support for each model using a dataset of bill shape differences in 207 pairs of New World terrestrial birds representing 30 avian families. We find that character displacement models are overwhelmingly supported over species sorting and null expectations, indicating that exaggerated bill shape differences in sympatric pairs result from enhanced divergent selection in sympatry. We additionally detect a latitudinal gradient in character displacement, which appears strongest in the tropics. Our analysis implicates costly species interactions as powerful drivers of trait divergence in a major vertebrate fauna. These results help substantiate a long-standing but equivocally supported linchpin of evolutionary theory.

Phenological displacement is uncommon among sympatric angiosperms

2020 ◽  
Author(s):  
Daniel S. Park ◽  
Ian K. Breckheimer ◽  
Aaron M. Ellison ◽  
Goia M. Lyra ◽  
Charles C. Davis
Keyword(s):  
Flowering Time ◽  
Related Species ◽  
Species Interactions ◽  
Spatial Scales ◽  
Character Displacement ◽  
Future Climate Change ◽  
Herbarium Specimens ◽  
Reproductive Character Displacement ◽  
Closely Related Species ◽  
Species Pairs

AbstractInteractions between species can influence access to resources and successful reproduction. One possible outcome of such interactions is reproductive character displacement. Here, the similarity of reproductive traits – such as flowering time – among close relatives growing in sympatry differ more so than when growing apart. However, evidence for the overall prevalence and direction of this phenomenon, or the stability of such differences under environmental change, remains untested across large taxonomic and spatial scales. We apply data from tens of thousands of herbarium specimens to examine character displacement in flowering time across 110 animal-pollinated angiosperm species in the eastern USA. We demonstrate that the degree and direction of phenological displacement among co-occurring closely related species pairs varies tremendously. Overall, flowering time displacement in sympatry is not common. However, displacement is generally greater among species pairs that flower close in time, regardless of direction. We additionally identify that future climate change may alter the nature of phenological displacement among many of these species pairs. On average, flowering times of closely related species were predicted to shift further apart by the mid-21st century, which may have significant future consequences for species interactions and gene flow.

scholarly journals No latitudinal gradients in tempo or mode of morphological evolution in birds

2020 ◽  
Author(s):  
J. Drury ◽  
J. Clavel ◽  
J.A. Tobias ◽  
J. Rolland ◽  
C. Sheard ◽  
...  
Keyword(s):  
Species Interactions ◽  
Morphological Evolution ◽  
Latitudinal Gradients ◽  
Phenotypic Evolution ◽  
Trait Evolution ◽  
Trait Divergence ◽  
Diversity Gradient ◽  
The Tropics ◽  
The Impact ◽  
Phylogenetic Models

AbstractThe latitudinal diversity gradient is one of the most striking patterns in nature yet its implications for morphological evolution are poorly understood. In particular, it has been proposed that an increased intensity of species interactions in tropical biota may either promote or constrain trait evolution, but which of these outcomes predominates remains uncertain. Here, we develop tools for fitting phylogenetic models of phenotypic evolution in which the impact of species interactions can vary across lineages. Deploying these models on a global avian trait dataset to explore differences in trait divergence between tropical and temperate lineages, we find that the effect of latitude on the mode and tempo of morphological evolution is weak and clade- or trait-dependent. Our results indicate that species interactions do not disproportionately impact morphological evolution in tropical bird families and question the validity and universality of previously reported patterns of slower trait evolution in the tropics.

scholarly journals An assessment of phylogenetic tools for analyzing the interplay between interspecific interactions and phenotypic evolution

2016 ◽  
Author(s):  
J.P. Drury ◽  
Grether G.F. ◽  
T. Garland ◽  
H. Morlon
Keyword(s):  
Species Interactions ◽  
Interspecific Interactions ◽  
Character Displacement ◽  
Statistical Properties ◽  
Reciprocal Effect ◽  
Closely Related Species ◽  
Phenotypic Diversification ◽  
The Impact ◽  
Further Development ◽  
Process Based Models

AbstractMuch ecological and evolutionary theory predicts that interspecific interactions often drive phenotypic diversification and that species phenotypes in turn influence species interactions. Several phylogenetic comparative methods have been developed to assess the importance of such processes in nature; however, the statistical properties of these methods have gone largely untested. Focusing mainly on scenarios of competition between closely-related species, we assess the performance of available comparative approaches for analyzing the interplay between interspecific interactions and species phenotypes. We find that currently used statistical methods largely fail to detect the impact of interspecific interactions on trait evolution, that sister taxa analyses often erroneously detect character displacement where it does not exist, and that recently developed process-based models have more satisfactory statistical properties. In weighing the strengths and weaknesses of different approaches, we hope to provide a clear guide for empiricists testing hypotheses about the reciprocal effect of interspecific interactions and species phenotypes and to inspire further development of process-based models.

scholarly journals Tempo and mode of morphological evolution are decoupled from latitude in birds

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001270
Author(s):  
Jonathan P. Drury ◽  
Julien Clavel ◽  
Joseph A. Tobias ◽  
Jonathan Rolland ◽  
Catherine Sheard ◽  
...  
Keyword(s):  
Species Interactions ◽  
Morphological Evolution ◽  
Phenotypic Evolution ◽  
Trait Evolution ◽  
Trait Divergence ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
The Tropics ◽  
The Impact ◽  
Phylogenetic Models

The latitudinal diversity gradient is one of the most striking patterns in nature, yet its implications for morphological evolution are poorly understood. In particular, it has been proposed that an increased intensity of species interactions in tropical biota may either promote or constrain trait evolution, but which of these outcomes predominates remains uncertain. Here, we develop tools for fitting phylogenetic models of phenotypic evolution in which the impact of species interactions—namely, competition—can vary across lineages. Deploying these models on a global avian trait dataset to explore differences in trait divergence between tropical and temperate lineages, we find that the effect of latitude on the mode and tempo of morphological evolution is weak and clade- or trait dependent. Our results indicate that species interactions do not disproportionately impact morphological evolution in tropical bird families and question the validity of previously reported patterns of slower trait evolution in the tropics.

scholarly journals A latitudinal gradient in rates of evolution of avian syllable diversity and song length

2010 ◽  
Vol 278 (1712) ◽  
pp. 1713-1720 ◽  
Author(s):  
Jason T. Weir ◽  
David Wheatcroft
Keyword(s):  
Species Diversity ◽  
Reproductive Isolation ◽  
New World ◽  
Latitudinal Gradient ◽  
Passerine Bird ◽  
Evolutionary Rates ◽  
High Latitudes ◽  
Rates Of Evolution ◽  
Low Latitudes ◽  
The Tropics

We ask whether rates of evolution in traits important for reproductive isolation vary across a latitudinal gradient, by quantifying evolutionary rates of two traits important for pre-mating isolation—avian syllable diversity and song length. We analyse over 2500 songs from 116 pairs of closely related New World passerine bird taxa to show that evolutionary rates for the two main groups of passerines—oscines and suboscines—doubled with latitude in both groups for song length. For syllable diversity, oscines (who transmit song culturally) evolved more than 20 times faster at high latitudes than in low latitudes, whereas suboscines (whose songs are innate in most species and who possess very simple song with few syllable types) show no clear latitudinal gradient in rate. Evolutionary rates in oscines and suboscines were similar at tropical latitudes for syllable complexity as well as for song length. These results suggest that evolutionary rates in traits important to reproductive isolation and speciation are influenced by latitude and have been fastest, not in the tropics where species diversity is highest, but towards the poles.

Into and out of the tropics: the generation of the latitudinal gradient among New World passerine birds

2014 ◽  
Vol 41 (9) ◽  
pp. 1746-1757 ◽  
Author(s):  
Jonathan D. Kennedy ◽  
Zhiheng Wang ◽  
Jason T. Weir ◽  
Carsten Rahbek ◽  
Jon Fjeldså ◽  
...  
Keyword(s):  
New World ◽  
Latitudinal Gradient ◽  
Passerine Birds ◽  
The Tropics

scholarly journals Global plant-frugivore trait matching is shaped by climate and biogeographic history

2021 ◽  
Author(s):  
Ian R. McFadden ◽  
Susanne A. Fritz ◽  
Niklaus E. Zimmermann ◽  
Loïc Pellissier ◽  
W. Daniel Kissling ◽  
...  
Keyword(s):  
Species Interactions ◽  
Latitudinal Gradient ◽  
Fruit Size ◽  
Global Scale ◽  
Frugivorous Birds ◽  
Biogeographic History ◽  
Gape Size ◽  
Avian Frugivores ◽  
Trait Structure ◽  
The Tropics

Species interactions are influenced by the trait structure of local multi-trophic communities. However, it remains unclear whether mutualistic interactions in particular can drive trait patterns at the global scale, where climatic constraints and biogeographic processes gain importance. Here we evaluate global relationships between traits of frugivorous birds and palms (Arecaceae), and how these relationships are affected, directly or indirectly, by assemblage richness, climate and biogeographic history. We leverage a new and expanded gape size dataset for nearly all avian frugivores, and find a positive relationship between gape size and fruit size, i.e., trait matching, which is influenced indirectly by palm richness and climate. We also uncover a latitudinal gradient in trait matching strength, which increases towards the tropics and varies among zoogeographic realms. Taken together, our results suggest trophic interactions have consistent influences on trait structure, but that abiotic, biogeographic and richness effects also play important, though sometimes indirect, roles in shaping the functional biogeography of mutualisms.

scholarly journals Losses of female song with changes from tropical to temperate breeding in the New World blackbirds

2009 ◽  
Vol 276 (1664) ◽  
pp. 1971-1980 ◽  
Author(s):  
J. Jordan Price ◽  
Scott M. Lanyon ◽  
Kevin E. Omland
Keyword(s):  
Sexual Selection ◽  
New World ◽  
Female Song ◽  
Complex Song ◽  
Evolutionary Changes ◽  
Apparent Relationship ◽  
Song Production ◽  
Selection For ◽  
The Tropics

Birds in which both sexes produce complex songs are thought to be more common in the tropics than in temperate areas, where typically only males sing. Yet the role of phylogeny in this apparent relationship between female song and latitude has never been examined. Here, we reconstruct evolutionary changes in female song and breeding latitude in the New World blackbirds (Icteridae), a family with both temperate and tropical representatives. We provide strong evidence that members of this group have moved repeatedly from tropical to temperate breeding ranges and, furthermore, that these range shifts were associated with losses of female song more often than expected by chance. This historical perspective suggests that male-biased song production in many temperate species is the result not of sexual selection for complex song in males but of selection against such songs in females. Our results provide new insights into the differences we see today between tropical and temperate songbirds, and suggest that the role of sexual selection in the evolution of bird song might not be as simple as we think.

Evolutionary conservatism will limit responses to climate change in the tropics

2021 ◽  
Vol 17 (10) ◽  
Author(s):  
Ethan B. Linck ◽  
Benjamin G. Freeman ◽  
C. Daniel Cadena ◽  
Cameron K. Ghalambor
Keyword(s):  
Thermal Tolerance ◽  
Species Turnover ◽  
Tropical Species ◽  
Evolutionary Divergence ◽  
Closely Related Species ◽  
Tropical Mountains ◽  
Low Latitudes ◽  
Parapatric Speciation ◽  
The Tropics

Rapid species turnover in tropical mountains has fascinated biologists for centuries. A popular explanation for this heightened beta diversity is that climatic stability at low latitudes promotes the evolution of narrow thermal tolerance ranges, leading to local adaptation, evolutionary divergence and parapatric speciation along elevational gradients. However, an emerging consensus from research spanning phylogenetics, biogeography and behavioural ecology is that this process rarely, if ever, occurs. Instead, closely related species typically occupy a similar elevational niche, while species with divergent elevational niches tend to be more distantly related. These results suggest populations have responded to past environmental change not by adapting and diverging in place, but instead by shifting their distributions to tightly track climate over time. We argue that tropical species are likely to respond similarly to ongoing and future climate warming, an inference supported by evidence from recent range shifts. In the absence of widespread in situ adaptation to new climate regimes by tropical taxa, conservation planning should prioritize protecting large swaths of habitat to facilitate movement.

Metacommunities

2019 ◽  
pp. 266-284
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Species Diversity ◽  
Species Interactions ◽  
Neutral Theory ◽  
Patch Dynamics ◽  
Species Traits ◽  
Local Communities ◽  
The Other ◽  
Species Sorting ◽  
Niche Differences ◽  
Dynamics Of Populations

Just as the dispersal of individuals may link the dynamics of populations in space, the dispersal of species among communities may link local communities into a metacommunity. Four different perspectives characterize how dispersal rates, environmental heterogeneity, and species traits interact to influence diversity in metacommunities. These perspectives are: patch dynamics, species sorting, mass effects, and the neutral perspective. The neutral perspective stands in stark contrast to the other three perspectives in that it assumes that niche differences between species are unimportant and that species are demographically identical in terms of their birth, death, and dispersal rates. Under the neutral perspective, species diversity is maintained by a balance between speciation, extinction, and dispersal. Although neutral theory is incompatible with realistic modes and rates of speciation, it has been enormously influential in focusing our attention on the linkages between species interactions on local scales, and evolutionary and biogeographic processes occurring on large scales.

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