Selection, recombination, and hybrid evolution Hybridization is an important force in evolution. The effects of hybridization across the whole genome are not understood. Using a fine-scale genetic map, Schumer et al. examined local ancestry replicate natural populations swordtail fish. Each parental species contributes different proportions material to genomes their descendants. Genes from “minor” (less well-represented) parent occur regions that subject higher recombination rates where...

Hybridization has long been considered a process that prevents divergence between species. In contrast to this historical view, an increasing number of empirical studies claim show evidence for hybrid speciation without ploidy change. However, the importance hybridization as route is poorly understood, and many claims have made with insufficient played role in process. We propose criteria determine strength homoploid speciation. Based on evaluation literature using framework, we conclude...

Swordtail fish (Poeciliidae: genus Xiphophorus ) are a paradigmatic case of sexual selection by sensory exploitation. Female preference for males with conspicuous “sword” ornament is ancestral, suggesting that male morphology has evolved in response to preexisting bias. The perceptual mechanisms underlying female mate choice have not been identified, complicating efforts understand the pressures acting on design. We consider two alternative models receiver behavior, each consistent previous...

Although private communication is considered an important diversifying force in evolution, there little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling northern swordtails (Xiphophorus) affords a channel for not accessible their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field experiments with (X. nigrensis) predators (A. mexicanus) demonstrate male UV ornamentation significantly increases attractiveness females...

It is well established that changes to the chemical environment can impair development, physiology and reproductive biology; by contrast, impacts on communication have not been widely reported. This surprising given most used sensory modality in nature, variation composition of rule, exception. Here, we show chemically mediated species recognition a swordtail fish, Xiphophorus birchmanni, be hindered anthropogenic disturbance signalling environment. Females strong preference for conspecific...

Hybridization is increasingly being recognized as a widespread process, even between ecologically and behaviorally divergent animal species. Determining phylogenetic relationships in the presence of hybridization remains major challenge for evolutionary biologists, but advances sequencing technology techniques are beginning to address these challenges. Here we reconstruct among swordtails platyfishes (Xiphophorus: Poeciliidae), group species characterized by remarkable morphological...

Hybridization is increasingly being recognized as a common process in both animal and plant species. Negative epistatic interactions between genes from different parental genomes decrease the fitness of hybrids can limit gene flow However, little known about number genome-wide distribution genetic incompatibilities separating To detect interacting genes, we perform high-resolution genome scan for linkage disequilibrium unlinked genomic regions naturally occurring hybrid populations swordtail...

Studies of highly diverged species have revealed two mechanisms by which meiotic recombination is directed to the genome—through PRDM9 binding or targeting promoter-like features—that lead dramatically different evolutionary dynamics hotspots. Here, we identify orthologs from genome and transcriptome data in 225 species. We find complete ortholog across distantly related vertebrates but, despite this broad conservation, infer a minimum six partial three losses. Strikingly, taxa carrying are...

Mapping vertebrate incompatibility alleles Deleterious gene interactions may underlie the observed hybrid incompatibilities. However, few genes underlying incompatibilities have been identified, and most of these involve species that do not hybridize in natural conditions. Powell et al. used genome sequencing to map likely responsible for reduce fitness naturally occurring swordtail fish. These combinations result malignant melanoma, which is found hybridizing populations but present...

Despite its role in homogenizing populations, hybridization has also been proposed as a means to generate new species. The conceptual basis for this idea is that can result novel phenotypes through recombination between the parental genomes, allowing hybrid population occupy ecological niches unavailable Here we present an alternative model of evolution reproductive isolation populations occurs simple consequence selection against genetic incompatibilities. Unlike previous models speciation,...

A rapidly increasing body of work is revealing that the genomes distinct species often exhibit hybrid ancestry, presumably due to postspeciation hybridization between closely related species. Despite growing number documented cases, we still know relatively little about how evolve and stabilize following hybridization, what extent functionally relevant. Here, examine case Xiphophorus nezahualcoyotl, a teleost fish whose genome exhibits significant ancestry. We show was ancient unlikely be...

The emergence of new species is driven by the establishment mechanisms that limit gene flow between populations. A major challenge reconciling theoretical and empirical importance assortative mating in speciation with ease which it can fail. Swordtail fish have an evolutionary history hybridization fragile prezygotic isolating mechanisms. Hybridization two swordtail likely arose via pollution-mediated breakdown 1990s. Here we track unusual genetic patterns one hybrid population over past...

Abstract Development consists of growth and differentiation, which can be partially decoupled affected by environmental factors to different extents. In amphibians, variation in the larval environment influences development causes changes post‐metamorphic shape. We examined consequences, both morphological locomotory, alterations development. reared tadpoles two phylogenetically ecologically distant frog species (the red‐eyed treefrog Agalychnis callidryas African clawed Xenopus laevis )...

Natural hybrid zones provide opportunities to study a range of evolutionary phenomena from speciation the genetic basis fitness-related traits. We show that widespread hybridization has occurred between two neo-tropical stream fishes with partial reproductive isolation. Phylogenetic analyses mitochondrial sequence data showed swordtail fish Xiphophorus birchmanni is monophyletic and X. malinche part an independent clade other species. Using informative single nucleotide polymorphisms in one...

Rapid technical advances in the field of computer animation (CA) and virtual reality (VR) have opened new avenues animal behavior research. Animated stimuli are powerful tools as they offer standardization, repeatability, complete control over stimulus presented, thereby "reducing" "replacing" animals used, "refining" experimental design line with 3Rs. However, appropriate use these technologies raises conceptual questions. In this review, we guidelines for common considerations related to...

Abstract Local adaptation is often invoked to explain hybrid zone structure, but empirical evidence of this generally rare. Hybrid zones between two poeciliid fishes, Xiphophorus birchmanni and X. malinche, occur in multiple tributaries with independent replication upstream‐to‐downstream gradients morphology allele frequencies. Ecological niche modelling revealed that temperature a central predictive factor the spatial distribution pure parental species their hybrids explains temporal...

Sexually dimorphic traits in many mate recognition systems have evolved response to preexisting female biases. These biases are often quite general form and likely be shared by predators, thereby imposing a cost on male trait expression. The Mexican tetra Astyanax mexicanus (Pisces: Characidae), visual predator of swordtail fishes, exhibits the same preferences for body size morphs as do females. Furthermore, tetras populations where swordtails absent prefer males with sword ornaments over...

Species recognition can often play a key role in female mating preferences. Far less is known about conspecific mate from the male perspective. In many closely related taxa, females exhibit few obvious visual differences and males might have to attend chemical cues recognition, possibility that has rarely been explored vertebrates. Here, we examine species via odor swordtail fish, Xiphophorus birchmanni. dichotomous choice experiments first tested whether respond cues. We found were...