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.

Altitudinal Variation in, and Morphological Divergence between, Three Related Species of Grasshopper, Praxibulus sp., Kosciuscola cognatus and K. usitatus (Orthoptera:Acrididae)

1980 ◽  
Vol 28 (1) ◽  
pp. 103 ◽  
Author(s):  
NA Campbell ◽  
JM Dearn
Keyword(s):  
Related Species ◽  
Character Displacement ◽  
Altitudinal Variation ◽  
Multivariate Statistical ◽  
Closely Related Species ◽  
Genetic Changes ◽  
Parallel Change ◽  
Variable Character ◽  
Multivariate Statistical Approach ◽  
Species Specific

Morphological variation between and within the closely related species Praxibuius sp.. Kosciuscola cognatus and K. usiratus has been examined along three independent altitudinal transects, by a multivariate statistical approach. The analyses, which were restricted to males. show that there is complete morphological separation between the three species. Moreover. there are species-specific patterns of character correlation which are consistent and relatively invariant within species, and do not exhibit altitudinal variation. The results suggest that there exist both distinct invariant species-specific character patterns and variable character patterns showing intraspecific variation. It is concluded that speciation in these grasshoppers could have involved genetic changes quite distinct from those involved in local intraspecific adaptation. Two further results are: first. evidence has been obtained for character displacement between Kosciuscola cognaius and Praxibulus sp. in an area of extensive sympatry: second. populations of K. cognatus along one transect, with a karyotype intermediate between typical K. cognatus and X usiiatus, show a parallel change in morphology towards that characteristic of K. usiiatus.

Taxonomic Account of Datura L. (Solanaceae) in Australia With a Note on Brugmansia Pers

1976 ◽  
Vol 24 (3) ◽  
pp. 415 ◽  
Author(s):  
L Haegi
Keyword(s):  
Central America ◽  
Related Species ◽  
Herbarium Specimens ◽  
Wild Populations ◽  
Closely Related Species ◽  
Current Usage ◽  
Identification Of Species

A taxonomic account of the genus Datura in Australia is presented. Wild populations of D. stramonium, D. ferox, D, leichhardtii, D, inoxia and D. wrightii occur and D. metel is cultivated and occasionally persistent. A comprehensive revision of the genus has not been attempted, but full descriptions based on a study of herbarium specimens, plants in the field and cultivated material are provided for each of the six species, of which five are naturalized aliens. D. leichhardtii has generally been considered an Australian endemic but the closely related species D. pruinosa (which may be conspecific) occurs in central America. This raises the biogeographical problems of trans-Pacific distribution. Although the application of names is in accordance with current usage, some nomenclatural problems are outlined. A key for the identification of species is presented. The genus Brugmansia, often treated as a section of Datura, is represented in Australia only by species in cultivation.

A model for character displacement based on competition between species

1974 ◽  
Vol 6 (1) ◽  
pp. 1-3
Author(s):  
M. G. Bulmer
Keyword(s):  
Related Species ◽  
Character Displacement ◽  
Geographical Range ◽  
Full Account ◽  
Closely Related Species ◽  
Displacement Based

When two closely-related species have a partially-overlapping geographical range, it sometimes happens that populations of the two species are very similar in the non-overlapping parts of the range where only one species is present, but that they diverge and are easily distinguishable in the area of overlap where both species occur together. This phenomenon is known as character displacement. One of the best known examples occurs in two species of Rock Nuthatches (Sitta neumayer and S. tephronota) in their area of overlap in Iran (Vaurie (1951)). A plausible explanation of this phenomenon is that it is due to competition between the two species. The purpose of this paper is to construct a model for character displacement based on this idea. A full account of this work will be published elsewhere (Bulmer (1973)).

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.

Chaetogastra cogniauxiana (Melastomataceae), a new Brazilian species from the Chaetogastra gracilis complex

Phytotaxa ◽  
2021 ◽  
Vol 511 (3) ◽  
Author(s):  
FABRÍCIO SCHMITZ MEYER ◽  
RENATO GOLDENBERG
Keyword(s):  
Species Richness ◽  
New Species ◽  
Related Species ◽  
Herbarium Specimens ◽  
Field Observations ◽  
Distribution Map ◽  
Closely Related Species ◽  
Great Species ◽  
Morphological Differences ◽  
Great Species Richness

Eleven varieties of Tibouchina gracilis were indicated as synonyms of Chaetogastra gracilis in the most recent work on the taxonomy of the genus. However, field observations and a more detailed analysis of herbarium specimens, including the types, led us to the conclusion that two of these varieties represent a single new species. Chaetogastra cogniauxiana is endemic to Brazil, and differs from C. gracilis by the smaller size, 10–70 cm tall (versus 30–120 cm tall in C. gracilis), dendritic-setose to dendritic-strigose hypanthium and bracteoles (vs. dendritic-sericeous hypanthium and bracteoles), and smaller petals, 9.8–13.4 × 8.8–9.1 mm (vs. larger petals, 16.5–21.6 × 11.2–14.8 mm). In this article, we provide a complete description of C. cogniauxiana, and indicate the main morphological differences between C. cogniauxiana and the most closely related species. We also provide comments on taxonomy and phylogenetic relationships of this species, photos, illustrations, and a distribution map. This work is part of a monograph of the genus Chaetogastra in Brazil, which showed a great species richness and also the necessity of several taxonomic adjustments.

A model for character displacement based on competition between species

1974 ◽  
Vol 6 (01) ◽  
pp. 1-3
Author(s):  
M. G. Bulmer
Keyword(s):  
Related Species ◽  
Character Displacement ◽  
Geographical Range ◽  
Full Account ◽  
Closely Related Species ◽  
Displacement Based

When two closely-related species have a partially-overlapping geographical range, it sometimes happens that populations of the two species are very similar in the non-overlapping parts of the range where only one species is present, but that they diverge and are easily distinguishable in the area of overlap where both species occur together. This phenomenon is known as character displacement. One of the best known examples occurs in two species of Rock Nuthatches (Sitta neumayer and S. tephronota) in their area of overlap in Iran (Vaurie (1951)). A plausible explanation of this phenomenon is that it is due to competition between the two species. The purpose of this paper is to construct a model for character displacement based on this idea. A full account of this work will be published elsewhere (Bulmer (1973)).

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.

scholarly journals The outcomes of most aggressive interactions among closely related bird species are asymmetric

2016 ◽  
Author(s):  
Paul R Martin ◽  
Cameron Freshwater ◽  
Cameron K Ghalambor
Keyword(s):  
Related Species ◽  
Selective Pressure ◽  
Statistical Tests ◽  
Bird Species ◽  
Evolutionary Strategies ◽  
Published Data ◽  
Closely Related Species ◽  
Aggressive Interactions ◽  
Species Pairs ◽  
Using Data

Aggressive interactions among closely related species are common. These can play an important role as a selective pressure shaping species, traits and assemblages. The nature of this selective pressure depends on whether the outcomes of aggressive contests are asymmetric between species (i.e., one species is consistently dominant), yet few studies have estimated the prevalence of asymmetric versus symmetric outcomes to aggressive contests. Here we use previously published data involving 26,656 interactions between 270 species pairs of birds from 26 taxonomic families to address the question: How often are aggressive interactions among closely related bird species asymmetric? We define asymmetry using (i) the proportion of contests won by one species, and (ii) statistical tests for asymmetric outcomes of aggressive contests. We calculate these asymmetries using data summed across different sites for each species pair, and compare results to asymmetries calculated using data separated by location. We find that 80% of species pairs had aggressive outcomes where one species won 80% or more of aggressive contests. We also find that the majority of aggressive interactions among closely related species show statistically significant asymmetries, and above a sample size of 52 interactions, all outcomes are asymmetric following binomial tests. Results using data partitioned by location showed similar patterns. Species pairs with dominance data from multiple sites showed the same dominance relationship across locations in 93% of the species pairs. Overall, our results suggest that the outcome of aggressive interactions among closely related species are usually consistent and asymmetric, and should thus favor ecological and evolutionary strategies specific to the position of a species within a dominance hierarchy.

Do Closely Related Species Influence Each Other's Sexual Size Dimorphism?

2018 ◽  
Author(s):  
Chloe Boynton
Keyword(s):  
Body Size ◽  
Related Species ◽  
Species Interactions ◽  
Sexual Size Dimorphism ◽  
Birds Of Prey ◽  
Closely Related Species ◽  
Size Dimorphism ◽  
Group I ◽  
Males And Females ◽  
Range Overlap

Size differences between males and females (sexual size dimorphism) are often seen in a variety of species. In birds of prey in particular, a phenomenon occurs where the female is larger than the male. One of the main hypotheses attempting to explain sexual size dimorphism in birds of prey is that the female and male differ in size to partition resources, like prey. There is also evidence that predator and prey body size are correlated, so predators of similar size may be in direct competition. It has been shown that when two closely related species interact in the same area, they are likely to be in competition for similar resources, like prey. This study is looking at sexual size dimorphism and closely related species interactions, which has never been looked at before in birds of prey. I am using the subfamily Buteoninae (Buteo Hawks) as my focal group. I will be using sexual size dimorphism ratios, estimates of genetic distance between closely related species and proportion of range overlap between different closely related lineages within the subfamily. I am expecting to see that if species are closely related and inhabit the same area they will have a decreased sexual size dimorphism. This is because both species are likely to be competing for the same resources, and to avoid competition the species will diverge in body size from one another. This will cause the male and female of each species to converge in size, reducing their sexual size dimorphism.

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