scholarly journals Counteracting Forces of Introgressive Hybridization and Interspecific Competition Shape the Morphological Traits of Cryptic Lberian Eptesicus Bats

Author(s):  
Pedro Horta ◽  
Helena Raposeira ◽  
Adrián Baños ◽  
Carlos Ibáñez ◽  
Orly Razgour ◽  
...  

Abstract Cryptic species that coexist in sympatry are likely to simultaneously experience strong competition and hybridization. The first phenomenon would lead to character displacement, whereas the second can potentially promote morphological similarity through adaptive introgression. The main goal of this work was to investigate the effect of introgressive hybridization on the morphology of cryptic Iberian Eptesicus bats when facing counteracting evolutionary forces from interspecific competition. We found substantial overlap both in dentition and in wing morphology traits, though mainly in individuals in sympatry. The presence of hybrids contributes to a fifth of this overlap, with hybrids showing traits with intermediate morphometry. Thus, introgressive hybridization may contribute to species adaptation to trophic and ecological space responding directly to the macro-habitats characteristics of the sympatric zone and to local prey availability. On the other hand, fur shade tended to be browner and brighter in hybrids than parental species. Colour differences could result from partitioning of resources as an adaptation to environmental factors such as roost and microhabitats. We argue that a balance between adaptive introgression and niche partitioning shapes species interactions with the environment through affecting morphological traits under selection.

2015 ◽  
Author(s):  
Anna M. O’Brien ◽  
Ruairidh J.H. Sawers ◽  
Jeffrey Ross-Ibarra ◽  
Sharon Y. Strauss

AbstractThe outcomes of many species interactions are conditional on the environments in which they occur. A common pattern is that outcomes grade from being more positive under stressful conditions to more antagonistic or neutral under benign conditions. The evolutionary implications of conditionality in interactions have received much less attention than the documentation of conditionality itself, with a few notable exceptions. Here, we predict patterns of adaptation and co-adaptation between partners along abiotic gradients, positing that when interactions become more positive in stressful environments, fitness outcomes for mutations affecting interactions align across partners and selection should favor greater mutualistic adap-tation and co-adaptation between interacting species. As a corollary, in benign environments, if interactions are strongly antagonistic, we predict antagonistic co-adaptation resulting in Red Queen or arms-race dynamics, or reduction of antagonism through character displacement and niche partitioning. We predict no adaptation if interactions are more neutral. We call this the CoCoA hypothesis: (Co)-adaptation and Conditionality across Abiotic gradients. We describe experimental designs and statistical models that allow testing predictions of CoCoA, with a focus on positive interactions. While only one study has included all the elements to test CoCoA, we briefly review the literature and summarize study findings relevant to CoCoA and highlight opportunities to test CoCoA further.


2021 ◽  
Author(s):  
Abraham Morales-Cruz ◽  
Jonas Aguirre-Liguori ◽  
Yongfeng Zhou ◽  
Andrea Minio ◽  
Summaira Riaz ◽  
...  

ABSTRACTIntrogressive hybridization can introduce adaptive genetic variation into a species or population. To evaluate the evolutionary forces that contribute to introgression, we studied six Vitis species that are native to the Southwestern United States and potentially useful for breeding grapevine (V. vinifera) rootstocks. By creating a reference genome from one wild species, V. arizonica, and by resequencing 130 accessions, we focused on identifying putatively introgressed regions (pIRs) between species. We found that up to ~8% of extant genome is attributable to introgression between species. The pIRs tended to be gene poor, located in regions of high recombination and enriched for genes implicated in disease resistance functions. To assess potential pIR function, we explored SNP associations to bioclimatic variables and to bacterial levels after infection with the causative agent of Pierce’s Disease. pIRs were enriched for SNPs associated with both climate and bacterial levels, suggesting potential drivers of adaptive events. Altogether, this study yields insights into the genomic extent of introgression, potential pressures that shape adaptive introgression, and the history of economically important wild relatives of a critical crop.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina Petalas ◽  
Thomas Lazarus ◽  
Raphael A. Lavoie ◽  
Kyle H. Elliott ◽  
Mélanie F. Guigueno

AbstractSympatric species must sufficiently differentiate aspects of their ecological niche to alleviate complete interspecific competition and stably coexist within the same area. Seabirds provide a unique opportunity to understand patterns of niche segregation among coexisting species because they form large multi-species colonies of breeding aggregations with seemingly overlapping diets and foraging areas. Recent biologging tools have revealed that colonial seabirds can differentiate components of their foraging strategies. Specifically, small, diving birds with high wing-loading may have small foraging radii compared with larger or non-diving birds. In the Gulf of St-Lawrence in Canada, we investigated whether and how niche differentiation occurs in four incubating seabird species breeding sympatrically using GPS-tracking and direct field observations of prey items carried by adults to chicks: the Atlantic puffin (Fratercula arctica), razorbill (Alca torda), common murre (Uria aalge), and black-legged kittiwake (Rissa tridactyla). Although there was overlap at foraging hotspots, all species differentiated in either diet (prey species, size and number) or foraging range. Whereas puffins and razorbills consumed multiple smaller prey items that were readily available closer to the colony, murres selected larger more diverse prey that were accessible due to their deeper diving capability. Kittiwakes compensated for their surface foraging by having a large foraging range, including foraging largely at a specific distant hotspot. These foraging habitat specialisations may alleviate high interspecific competition allowing for their coexistence, providing insight on multispecies colonial living.


2015 ◽  
Vol 282 (1808) ◽  
pp. 20150520 ◽  
Author(s):  
Jay J. Falk ◽  
Hannah M. ter Hofstede ◽  
Patricia L. Jones ◽  
Marjorie M. Dixon ◽  
Paul A. Faure ◽  
...  

Many predators and parasites eavesdrop on the communication signals of their prey. Eavesdropping is typically studied as dyadic predator–prey species interactions; yet in nature, most predators target multiple prey species and most prey must evade multiple predator species. The impact of predator communities on prey signal evolution is not well understood. Predators could converge in their preferences for conspicuous signal properties, generating competition among predators and natural selection on particular prey signal features. Alternatively, predator species could vary in their preferences for prey signal properties, resulting in sensory-based niche partitioning of prey resources. In the Neotropics, many substrate-gleaning bats use the mate-attraction songs of male katydids to locate them as prey. We studied mechanisms of niche partitioning in four substrate-gleaning bat species and found they are similar in morphology, echolocation signal design and prey-handling ability, but each species preferred different acoustic features of male song in 12 sympatric katydid species. This divergence in predator preference probably contributes to the coexistence of many substrate-gleaning bat species in the Neotropics, and the substantial diversity in the mate-attraction signals of katydids. Our results provide insight into how multiple eavesdropping predator species might influence prey signal evolution through sensory-based niche partitioning.


2019 ◽  
Author(s):  
Sadoune Ait Kaci Azzou ◽  
Liam Singer ◽  
Thierry Aebischer ◽  
Madleina Caduff ◽  
Beat Wolf ◽  
...  

SummaryCamera traps and acoustic recording devices are essential tools to quantify the distribution, abundance and behavior of mobile species. Varying detection probabilities among device locations must be accounted for when analyzing such data, which is generally done using occupancy models. We introduce a Bayesian Time-dependent Observation Model for Camera Trap data (Tomcat), suited to estimate relative event densities in space and time. Tomcat allows to learn about the environmental requirements and daily activity patterns of species while accounting for imperfect detection. It further implements a sparse model that deals well will a large number of potentially highly correlated environmental variables. By integrating both spatial and temporal information, we extend the notation of overlap coefficient between species to time and space to study niche partitioning. We illustrate the power of Tomcat through an application to camera trap data of eight sympatrically occurring duiker Cephalophinae species in the savanna - rainforest ecotone in the Central African Republic and show that most species pairs show little overlap. Exceptions are those for which one species is very rare, likely as a result of direct competition.


Author(s):  
Benjamin A. Turschak ◽  
Charles R. Bronte ◽  
Sergiusz J. Czesny ◽  
Brandon S. Gerig ◽  
Austin Happel ◽  
...  

Stable isotope analyses offer a useful means for quantifying ecological niche dimensions, though few studies have examined isotopic response of an ecological community with respect to resource gradients such as fluctuations in prey availability. Stable carbon and nitrogen isotopes were measured for Lake Michigan salmonines and their prey collected from 2014 to 2016. Bayesian ellipse and mixing model analyses were used to quantify isotopic niche characteristics and diets, respectively, among species and years. During the three-year study period, abundance and size structure of preferred alewife prey changed substantially and offered an opportunity to explore predator isotopic niche response and diet shifts along a prey resource gradient. Results suggested increased reliance on alewives, especially small alewives, over the study period and were consistent with greater availability of this prey. However, differential use of alewife size classes and alternative prey sources by salmonine predators was apparent, which suggested possible resource partitioning. Characterization of ecological niche overlap using stable isotopes likely requires consideration of shared resource availability as well as specific prey and habitat preferences.


2020 ◽  
pp. 447-471
Author(s):  
Matthias Galipaud ◽  
Loïc Bollache ◽  
Clément Lagrue

Recent advances in molecular and genetic techniques have revealed tremendous hidden genetic diversity in plants and animals. Crustaceans are no exception and, in fact, present one of the highest levels of cryptic diversity among the metazoans. Beyond the importance of such discovery and its multiple implications for taxonomy and ecology, it is now timely to investigate the potential causes of cryptic diversity. This chapter reviews the theoretical and experimental literature, seeking evidences for a relationship between sexual selection and cryptic diversity in crustaceans. It proposes three scenarios for the role of sexual selection on the origin and maintenance of pre-mating isolation and genetic divergence among crustacean populations, and suggests ways to discriminate among them experimentally or using existing data. Assuming that taxonomic identification is largely based on differences in sexually selected morphological traits, it also reviews evidence for a cryptic action of sexual selection on crustacean phenotypes. Specifically, if sexual selection acts primarily on chemical, visual, or behavioral traits, it is likely that allopatric crustacean populations remain morphologically similar even when they are reproductively isolated. This review shows that the strength of sexual selection likely differs among allopatric populations but does not seem to consistently induce pre-mating isolation (e.g. as in copepods and amphipods). Research is now needed to try to identify general patterns and determine the role of sexual selection on pre-mating isolation after secondary contact between populations, through reinforcement and reproductive character displacement.


2020 ◽  
Author(s):  
Daniel S. Park ◽  
Ian K. Breckheimer ◽  
Aaron M. Ellison ◽  
Goia M. Lyra ◽  
Charles C. Davis

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.


1987 ◽  
Vol 119 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Daniel Coderre ◽  
Louis Provencher ◽  
Jean-Claude Tourneur

AbstractPrincipal components analysis was used to assess niche partitioning between four aphid predators on the basis of oviposition strategies. The study was conducted by sampling abundance and position of the eggs of these predators in corn monocultures in two locations of southern Quebec. The results indicated that the chrysopid Chrysopa occulata Say laid its eggs on corn leaves usually without aphid colonies, and late in the season. All other predators reacted to aphid concentrations. The syrphid Sphaerophoria philanthus (Mg.) oviposited close to the ground, early in the season, and among colonies of the aphid Rhopalosiphum padi (L.). The two coccinellids laid their eggs during July and August with a maximum during tasseling for Coleomegilla maculata lengi (Timberlake) and after pollination for Hippodamia tredecimpunctata tibialis Say. Of these two species, the latter one selected sites at higher levels on the plant, and was more abundant at the edges of the field. It is suggested that the observed niche partitioning cannot be the result of interspecific competition in variable environments such as maize monocultures.


1998 ◽  
Vol 29 (4) ◽  
pp. 451-457 ◽  
Author(s):  
Zuzana Kučerová

AbstractNew wing morphs of the synanthropic psocid Dorypteryx domestica are described, including wing morphology and body measurements. These forms are intermediate in wing length and other morphological traits between normal brachypterous and fully macropterous morphs. These individuals were reared from brachypterous parents in a laboratory culture. Aspects of alary polymorphism are discussed.


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