scholarly journals Continental variation in wing pigmentation in Calopteryx damselflies is related to the presence of heterospecifics

2014 ◽  
Author(s):  
Christopher Hassall
Keyword(s):  
Character Displacement ◽  
Step Change ◽  
Strong Variation ◽  
Closely Related Species ◽  
Wing Pigmentation ◽  
Primary Driver ◽  
Potential Benefits ◽  
Southern Border ◽  
Calopteryx Maculata ◽  
Discrete Populations

Wing pigmentation in Calopteryx damselflies, caused by the deposition of melanin, is energetically expensive to produce and enhances predation risk. However, patterns of melanisation are used in species identification, greater pigmentation is an accurate signal of male immune function in at least some species, and there may be a role for pigment in thermoregulation. This study tested two potential hypotheses to explain the presence of, and variation in, this pigmentation based on these three potential benefits using 907 male specimens of Calopteryx maculata collected from 49 sites (34 discrete populations) across the geographical range of the species in North America: (i) pigmentation varies with the presence of the closely related species, Calopteryx aequabilis, and (ii) pigment increases at higher latitudes as would be expected if it enhances thermoregulatory capacity. No gradual latitudinal pattern was observed, as might be expected if pigmentation was involved in thermoregulation. However, strong variation was observed between populations that were sympatric or allopatric with C. aequabilis. This variation was characterised by dark wings through allopatry in the south of the range and then a step change to much lighter wings at the southern border of sympatry. Pigmentation then increased further north into the sympatric zone, finally returning to allopatry levels at the northern range margin. These patterns are qualitatively similar to variation in pigmentation in C. aequabilis, meaning that the data are consistent with what would be expected from convergent character displacement. Overall, the results corroborate recent research that has suggested sexual selection as a primary driver behind the evolution of wing pigmentation in this group.

scholarly journals Continental variation in wing pigmentation in Calopteryx damselflies is related to the presence of heterospecifics

2014 ◽  
Author(s):  
Christopher Hassall
Keyword(s):  
Character Displacement ◽  
Step Change ◽  
Strong Variation ◽  
Closely Related Species ◽  
Wing Pigmentation ◽  
Primary Driver ◽  
Potential Benefits ◽  
Southern Border ◽  
Calopteryx Maculata ◽  
Discrete Populations

Wing pigmentation in Calopteryx damselflies, caused by the deposition of melanin, is energetically expensive to produce and enhances predation risk. However, patterns of melanisation are used in species identification, greater pigmentation is an accurate signal of male immune function in at least some species, and there may be a role for pigment in thermoregulation. This study tested two potential hypotheses to explain the presence of, and variation in, this pigmentation based on these three potential benefits using 907 male specimens of Calopteryx maculata collected from 49 sites (34 discrete populations) across the geographical range of the species in North America: (i) pigmentation varies with the presence of the closely related species, Calopteryx aequabilis, and (ii) pigment increases at higher latitudes as would be expected if it enhances thermoregulatory capacity. No gradual latitudinal pattern was observed, as might be expected if pigmentation was involved in thermoregulation. However, strong variation was observed between populations that were sympatric or allopatric with C. aequabilis. This variation was characterised by dark wings through allopatry in the south of the range and then a step change to much lighter wings at the southern border of sympatry. Pigmentation then increased further north into the sympatric zone, finally returning to allopatry levels at the northern range margin. These patterns are qualitatively similar to variation in pigmentation in C. aequabilis, meaning that the data are consistent with what would be expected from convergent character displacement. Overall, the results corroborate recent research that has suggested sexual selection as a primary driver behind the evolution of wing pigmentation in this group.

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.

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.

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 Drivers of inter-population variation in the gut microbiomes of sister species of Phanaeus dung beetles

2021 ◽  
Author(s):  
Claire C. Winfrey ◽  
Kimberly S. Sheldon
Keyword(s):  
Microbial Communities ◽  
Niche Partitioning ◽  
Dung Beetle ◽  
Character Displacement ◽  
Climatic Conditions ◽  
Population Variation ◽  
Sister Species ◽  
Closely Related Species ◽  
Temperature And Precipitation ◽  
Symbiotic Microbiota

ABSTRACTThe microbiome plays key roles in host physiology and ecology, but how the microbiome varies among populations of hosts is not well understood. However, different abiotic and biotic selection pressures across a species’ range likely lead to variation in the microbiome. In addition, symbiotic microbiota may differ more between closely-related species in sympatry than in allopatry if selection favors the reduction of interspecific competition. We investigated variation in the maternally-transmitted, beneficial gut microbiomes of Phanaeus vindex and P. difformis, sister species of dung beetle that compete for the same resources in sympatry and occur across diverse climatic conditions. We sampled and sequenced bacterial/archaeal 16S rDNA from guts of P. difformis and P. vindex collected across 17 sympatric and allopatric sites. Gut microbial communities were best predicted by temperature and precipitation, cattle present at sites, and spatial relationships among sites. Contrary to our hypotheses, we did not find that the gut microbial communities of P. vindex and P. difformis differed more in sympatry than in allopatry, nor that P. vindex, the more broadly distributed of the two species, exhibited greater microbiome turnover among populations. However, the gut microbiome of P. vindex shifted more between sympatric and allopatric populations than did that of P. difformis, suggesting character displacement. While more research is needed, it is possible that differences in gut microbial communities allow P. vindex and P. difformis to partition their niches in sympatry. Our work argues for further exploration of the gut microbiome’s potential role in niche partitioning and local adaptation.

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.

Zur innerartlichen Gliederung und zur Artgeschichte von Chamaeleo quadricornis TORNIER, 1899 (Sauria: Chamaeleonidae)

1980 ◽  
Vol 1 (3) ◽  
pp. 313-328 ◽  
Author(s):  
Charles J. J. Klaver ◽  
Wolfgang Böhme
Keyword(s):  
Related Species ◽  
Character Displacement ◽  
The Other ◽  
Museum Collections ◽  
Closely Related Species ◽  
Historical Interpretation ◽  
History Of ◽  
The One ◽  
Phylogenetic Affinities ◽  
Geographical Characteristics

AbstractIn this paper all material of Chamaeleo quadricornis, present in museum collections, has been studied. Using morphological and geographical characteristics two subspecies are recognized, one of which is new: Chamaeleo quadricornis gracilior ssp. n. The history of the species has been reconstructed, using schemes of the orographic profile of West Cameroon, which furnishes a historical interpretation for the new subspecies. The closely related species C. eisentrauti and C. montium have also been discussed in this context. The assumed phylogenetic affinities are represented in a phylogram. This leads us to the following hypotheses: - in the Tchabal Mbabo mountains, which have hardly been explored faunistically, there probably lives a chameleon, that resembles C. quadricornis. - the differentiation in characteristics between C. montium and the sympatric C. eisentrauti and C. q. quadricornis (both being mutually allopatric) on the one hand and the allopatric C. q. gracilior ssp. n. on the other hand can be explained by "character displacement".

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