Resource competition has long been viewed as a major cause of phenotypic divergence within and between species. Theory predicts that arises because natural selection favors individuals are phenotypically dissimilar from their competitors. Yet, there few conclusive tests this key prediction. Drawing on data both populations controlled experiment, paper presents such test in tadpoles two species spadefoot toads (Spea bombifrons S. multiplicata). These show exaggerated trophic morphology where...

We investigated the roles of resource availability and phenotypic plasticity in promoting ecological character displacement (i.e., trait evolution stemming from competition between species). Because generates new populations that differ use, this process should only occur when exploitable resources are available. tested hypothesis two species spadefoot toads (Spea bombifrons S. multiplicata) whose tadpoles use to develop into either an omnivore morph, which specializes on detritus, or a...

Abstract The relative contributions of climate versus interspecific interactions in shaping species distributions have important implications for closely related at contact zones. When hybridization occurs within a zone, these factors regulate hybrid zone location and movement. While zone's position may depend on both between the hybridizing species, little is known about how interact to affect dynamics. Here, we utilize SDM (species distribution modeling) characterize affecting current...

Interest in ecological speciation is growing, as evidence accumulates showing that natural selection can lead to rapid divergence between subpopulations. However, whether and how the buildup of reproductive isolation remains under debate. What relative importance vs. neutral processes? How does adaptation generate isolation? Can occur despite homogenizing gene flow? These questions be addressed using genomic approaches, with development technology, will become more answerable studies wild...

Abstract With the access to draft genome sequence assemblies and whole‐genome resequencing data from population samples, molecular ecology studies will be able take truly genome‐wide approaches. This now applies an avian model system in ecological evolutionary research: Old World flycatchers of genus F icedula , for which we recently obtained a 1.1 Gb collared flycatcher assembly identified 13 million single‐nucleotide polymorphism ( SNP )s this species its sister species, pied flycatcher....

Reproductive character displacement is the adaptive evolution of traits that minimize deleterious reproductive interactions between species. When arising from selection to avoid hybridization, this process referred as reinforcement. generates divergence not only interacting species, but also conspecific populations are sympatric with heterospecifics versus those allopatric. Consequently, such can become reproductively isolated. We compared female mate preferences in, and evaluated gene flow...

Identifying the phenotypes underlying postzygotic reproductive isolation is crucial for fully understanding evolution and maintenance of species. One potential isolating barrier that has rarely been examined learning memory ability in hybrids. Learning are important fitness‐related traits, especially scatter‐hoarding species, where accurate retrieval hoarded food vital winter survival. Here, we test hypothesis can act as a by comparing these traits among two songbird black‐capped (Poecile...

Character displacement can reduce costly interspecific interactions between young species. We investigated the mechanisms behind divergence in three key traits-breeding habitat choice, timing of breeding, and plumage coloration-in Ficedula flycatchers. found that male pied flycatchers became expelled from preferred deciduous into mixed forest as superior competitor, collared flycatchers, increased numbers. The peak food abundance differs habitats, spatial segregation was paralleled by an...

How species' ranges evolve remains an enduring problem in ecology and evolutionary biology. Species' range limits are potentially set by the inability of peripheral populations to adapt range-edge habitat. Indeed, often assumed have reduced genetic diversity population sizes, which limit evolvability. However, support for this assumption is mixed, possibly because effects expansion depend on two factors: extent that habitat into occurs novel sources gene flow. Here, we used spadefoot toads,...

Abstract Character displacement – trait evolution stemming from selection to lessen resource competition or reproductive interactions between species has long been regarded as important in finalizing speciation. By contrast, its role initiating speciation received less attention. Yet because for character should act only where co‐occur, individuals sympatry will experience a different pattern of than conspecifics allopatry. Such divergent might favour reduced gene flow conspecific...

Postzygotic isolation may be important for maintaining species boundaries, particularly when premating barriers are incomplete. Little is known about the course of events leading from minor environmental mismatches affecting hybrid fitness to severe genetic incompatibilities causing sterility or inviability. We investigated whether reduced reproductive success males was caused by suboptimal sperm traits more in a zone pied ( Ficedula hypoleuca ) and collared flycatchers F. albicollis on...

Abstract Understanding how mating cues promote reproductive isolation upon secondary contact is important in describing the speciation process animals. Divergent chemical have been shown to act across many animal taxa. However, such overlooked avian speciation, particularly passerines, favor of more traditional signals as song and plumage. Here, we aim test potential for odor a mate choice cue, therefore contribute premating between black‐capped ( Poecile atricapillus ) Carolina chickadee P....

Abstract Ecological character displacement occurs when interacting species diverge in resource use and associated traits response to selection minimize competition between them. Yet, quality is asymmetric, the that monopolizes more profitable following may have higher fitness therefore be deemed ‘winner’. Here, we ask: does winner tend resident (i.e. earlier inhabitant of geographic region where occurred) or invader subsequent region)? We focus on two spadefoot toad undergone displacement....

Ecological character displacement—trait evolution stemming from selection to lessen resource competition between species—is most often inferred a pattern in which species differ resource-use traits sympatry but not allopatry, and sympatric populations within each conspecific allopatric populations. Yet, without information on population history, the presence of divergent phenotype multiple does necessarily imply that there has been repeated displacement. Instead, such may arise if...

Ecological character displacement takes place when two closely related species co-occur in only part of their geographical range, and selection to minimize competition between them promotes divergence resource-use traits sympatry but not allopatry. Because populations sympatric with the heterospecific competitor will experience a different competitive environment than conspecific allopatry, from these environments also diverge resource as an indirect consequence interspecific ecological...

Abstract Plant traits that show little variation across higher taxa are often used as diagnostic traits, but the reason for stasis of such remains unclear. Wild radish, Raphanus raphanistrum, exhibits tetradynamous stamens (four long and two short, producing a dimorphism in anther height within each flower), do vast majority more than 3000 species Brassicaceae. Here we examine hypothesis selection maintains dimorphic by investigating effects this trait on pollen removal, seed siring success,...

As DNA sequencing technology continues to rapidly improve, studies investigating the microbial communities of host organisms (i.e., microbiota) are becoming not only more popular but also financially accessible. Across many taxa, microbiomes can have important impacts on organismal health and fitness. To evaluate community composition a particular microbiome, must be successfully extracted. Fecal samples often easy collect good source gut DNA. Additionally, interest in avian preen gland...