scholarly journals What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies

2017 ◽  
Author(s):  
C. Mérot ◽  
C. Salazar ◽  
R. M. Merrill ◽  
C. Jiggins ◽  
M. Joron
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Habitat Isolation ◽  
Wing Pattern ◽  
Key Factor ◽  
Comparative Results ◽  
Phylogenetic Divergence

AbstractThe process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographic and phylogenetic divergence. We carry out a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius. Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern, also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it is not essential at a higher level. Additional factors including habitat isolation, hybrid sterility and chemically-mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasised the role of wing pattern, our comparative results highlight that speciation is a multidimensional process, whose completion is stabilized by many factors.

scholarly journals What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170335 ◽  
Author(s):  
C. Mérot ◽  
C. Salazar ◽  
R. M. Merrill ◽  
C. D. Jiggins ◽  
M. Joron
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Wing Pattern ◽  
Key Factor ◽  
Comparative Results ◽  
Phylogenetic Divergence ◽  
The Continuum

The process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographical, and phylogenetic divergence. Here, we report a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius . Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it may become facultative at later stages of divergence. Additional factors including habitat partitioning, hybrid sterility, and chemically mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasized the role of wing pattern, our comparative results highlight that speciation is a multi-dimensional process, whose completion is stabilized by many factors.

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

scholarly journals The role of copy-number variation in the reinforcement of sexual isolation between the two European subspecies of the house mouse

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190540 ◽  
Author(s):  
Henry L. North ◽  
Pierre Caminade ◽  
Dany Severac ◽  
Khalid Belkhir ◽  
Carole M. Smadja
Keyword(s):  
Mate Choice ◽  
Copy Number Variation ◽  
Reproductive Isolation ◽  
House Mouse ◽  
Copy Number ◽  
Structural Changes ◽  
Sexual Isolation ◽  
Number Variation ◽  
Tandem Duplications

Reinforcement has the potential to generate strong reproductive isolation through the evolution of barrier traits as a response to selection against maladaptive hybridization, but the genetic changes associated with this process remain largely unexplored. Building upon the increasing evidence for a role of structural variants in adaptation and speciation, we addressed the role of copy-number variation in the reinforcement of sexual isolation evidenced between the two European subspecies of the house mouse. We characterized copy-number divergence between populations of Mus musculus musculus that display assortative mate choice, and those that do not, using whole-genome resequencing data. Updating methods to detect deletions and tandem duplications (collectively: copy-number variants, CNVs) in Pool-Seq data, we developed an analytical pipeline dedicated to identifying genomic regions showing the expected pattern of copy-number displacement under a reinforcement scenario. This strategy allowed us to detect 1824 deletions and seven tandem duplications that showed extreme differences in frequency between behavioural classes across replicate comparisons. A subset of 480 deletions and four tandem duplications were specifically associated with the derived trait of assortative mate choice. These ‘Choosiness-associated’ CNVs occur in hundreds of genes. Consistent with our hypothesis, such genes included olfactory receptors potentially involved in the olfactory-based assortative mate choice in this system as well as one gene, Sp110 , that is known to show patterns of differential expression between behavioural classes in an organ used in mate choice—the vomeronasal organ. These results demonstrate that fine-scale structural changes are common and highly variable within species, despite being under-studied, and may be important targets of reinforcing selection in this system and others. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.

scholarly journals Testing the Role of Habitat Isolation among Ecologically Divergent Gall Wasp Populations

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Scott P. Egan ◽  
Glen R. Hood ◽  
James R. Ott
Keyword(s):  
Reproductive Isolation ◽  
Assortative Mating ◽  
Host Plants ◽  
Habitat Preferences ◽  
Habitat Isolation ◽  
Native Plant ◽  
Gall Wasp ◽  
Quercus Virginiana ◽  
Respective Host

Habitat isolation occurs when habitat preferences lower the probability of mating between individuals associated with differing habitats. While a potential barrier to gene flow during ecological speciation, the effect of habitat isolation on reproductive isolation has rarely been directly tested. Herein, we first estimated habitat preference for each of six populations of the gall waspBelonocnema treataeinhabiting eitherQuercus virginianaorQ. geminata. We then estimated the importance of habitat isolation in generating reproductive isolation betweenB. treataepopulations that were host specific to eitherQ. virginianaorQ. geminataby measuring mate preference in the presence and absence of the respective host plants. All populations exhibited host preference for their native plant, and assortative mating increased significantly in the presence of the respective host plants. This host-plant-mediated assortative mating demonstrates that habitat isolation likely plays an important role in promoting reproductive isolation among populations of this host-specific gall former.

scholarly journals Modular prophage interactions driven by capsule serotype select for capsule loss under phage predation

2019 ◽  
Author(s):  
Jorge A. Moura de Sousa ◽  
Amandine Buffet ◽  
Matthieu Haudiquet ◽  
Eduardo P.C. Rocha ◽  
Olaya Rendueles
Keyword(s):  
Population Dynamics ◽  
Gene Flow ◽  
Klebsiella Pneumoniae ◽  
Species Complex ◽  
Interaction Network ◽  
Lytic Cycle ◽  
Nosocomial Pathogens ◽  
Wide Range ◽  
Key Factor

ABSTRACTKlebsiella species are able to colonize a wide range of environments and include worrisome nosocomial pathogens. Here, we sought to determine the abundance and infectivity of prophages of Klebsiella to understand how the interactions between induced prophages and bacteria affect population dynamics and evolution. We identified many prophages in the species, placing these taxa among the top 5% of the most polylysogenic bacteria. We selected 35 representative strains of the Klebsiella pneumoniae species complex to establish a network of induced phage-bacteria interactions. This revealed that many prophages are able to enter the lytic cycle, and subsequently kill or lysogenize closely-related Klebsiella strains. Although 60% of the tested strains could produce phages that infect at least one other strain, the interaction network of all pairwise cross-infections is very sparse and mostly organized in modules corresponding to the strains’ capsule serotypes. Accordingly, capsule mutants remain uninfected showing that the capsule is a key factor for successful infections. Surprisingly, experiments in which bacteria are predated by their own prophages result in accelerated loss of the capsule. Our results show that phage infectiousness defines interaction modules between small subsets of phages and bacteria in function of capsule serotype. This limits the role of prophages as competitive weapons because they can infect very few strains of the species complex. This should also restrict phage-driven gene flow across the species. Finally, the accelerated loss of the capsule in bacteria being predated by their own phages, suggests that phages drive serotype switch in nature.

scholarly journals Sexual isolation with and without ecological isolation in marine isopods J. albifrons and J. praehirsuta

2018 ◽  
Author(s):  
Ambre Ribardière ◽  
Elsa Pabion ◽  
Jérôme Coudret ◽  
Claire Daguin-Thiébaut ◽  
Céline Houbin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Free Choice ◽  
First Generation ◽  
Sexual Isolation ◽  
Relative Strength ◽  
Experimental Population ◽  
Species Pair ◽  
Ecological Isolation

AbstractSexual barriers associated with mate choice are nearly always found to be associated with some level of ecological isolation between species. The independence and relative strength of sexual isolation are thus difficult to assess. Here we take advantage of a pair of isopod species (Jaera albifrons and J. praehirsuta) that show sexual isolation and coexist in populations where they share the same microhabitat or not (i.e. without or with ecological isolation). Using no-choice trials and a free-choice experimental population, we estimated the strength of sexual isolation between J. albifrons and J. praehirsuta individuals originating from these different ecological contexts. We found that sexual isolation is strong in presence and absence of ecological isolation, but that it is asymmetric and fails to prevent gene flow entirely. First-generation post-zygotic barriers were low, and there was no sexual isolation within J. praehirsuta across habitats. The J. albifrons / J. praehirsuta species pair thus provides an example where the role of sexual isolation as a barrier to gene flow i) does not depend upon current ecological isolation, ii) seems to have evolved independently of local ecological conditions, but iii) is insufficient to complete speciation entirely on its own.

scholarly journals Gene flow mediates the role of sex chromosome meiotic drive during complex speciation

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Colin D Meiklejohn ◽  
Emily L Landeen ◽  
Kathleen E Gordon ◽  
Thomas Rzatkiewicz ◽  
Sarah B Kingan ◽  
...  
Keyword(s):  
Gene Flow ◽  
Sex Chromosomes ◽  
Population Genomics ◽  
Sex Chromosome ◽  
Hybrid Sterility ◽  
Sequence Divergence ◽  
Meiotic Drive ◽  
Hybrid Male ◽  
Local Sequence

During speciation, sex chromosomes often accumulate interspecific genetic incompatibilities faster than the rest of the genome. The drive theory posits that sex chromosomes are susceptible to recurrent bouts of meiotic drive and suppression, causing the evolutionary build-up of divergent cryptic sex-linked drive systems and, incidentally, genetic incompatibilities. To assess the role of drive during speciation, we combine high-resolution genetic mapping of X-linked hybrid male sterility with population genomics analyses of divergence and recent gene flow between the fruitfly species, Drosophila mauritiana and D. simulans. Our findings reveal a high density of genetic incompatibilities and a corresponding dearth of gene flow on the X chromosome. Surprisingly, we find that a known drive element recently migrated between species and, rather than contributing to interspecific divergence, caused a strong reduction in local sequence divergence, undermining the evolution of hybrid sterility. Gene flow can therefore mediate the effects of selfish genetic elements during speciation.

scholarly journals Mate choice enhances post-zygotic barriers to gene flow via ancestry bundling

2021 ◽  
Author(s):  
Pavitra Muralidhar ◽  
Graham Coop ◽  
Carl Veller
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Assortative Mating ◽  
Hybrid Zones ◽  
Genetic Introgression ◽  
Genetic Isolation ◽  
Common Features ◽  
Genome Wide ◽  
Zygotic Selection

Hybridization and subsequent genetic introgression are now known to be common features of the histories of many species, including our own. Following hybridization, post-zygotic selection tends to purge introgressed DNA genome-wide. While mate choice can prevent hybridization in the first place, it is also known to play an important role in post-zygotic selection against hybrids, and thus the purging of introgressed DNA. However, this role is usually thought of as a direct one: a mating preference for conspecifics reduces the sexual fitness of hybrids, reducing the transmission of introgressed ancestry. Here, we explore a second, indirect role of mate choice as a barrier to gene flow. Under assortative mating, parents covary in their ancestry, causing ancestry to be "bundled" in their offspring and later generations. This bundling effect increases ancestry variance in the population, enhancing the efficiency with which post-zygotic selection purges introgressed DNA. Using whole-genome simulations, we show that the bundling effect can comprise a substantial portion of mate choice's overall effect as a postzygotic barrier to gene flow, and that it is driven by ancestry covariances both between and within maternally and paternally inherited genomes. Using estimates of the strength of assortative mating in avian hybrid zones, we calculate that the bundling effect of mate choice may increase the amount of purging of introgressed DNA by 40-80%, contributing substantially to the genetic isolation of species.

Mate Choice, Speciation, and Hybridization

Mate Choice ◽  
2017 ◽  
Author(s):  
Gil G. Rosenthal
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Genetic Exchange ◽  
Mating Preferences ◽  
Individual Mating ◽  
The Relationship ◽  
Isolated Species ◽  
Geographically Isolated

This chapter reviews the ample literature on mate choice and speciation, as well as the more novel topic of mate choice and genetic exchange among species. It begins by discussing the widespread support for the intuitive predictions that mate choice should promote diversification among geographically isolated species, and that mate choice should evolve to minimize drastic loss of fitness through hybridization. The role of mate choice is more complicated when there is incomplete divergence between lineages; depending on their relationship to other traits under selection, mating preferences can act to accelerate speciation through reinforcement, but they can also act to increase gene flow between divergent lineages. Finally, the chapter addresses the relationship between individual mating decisions and hybridization between species.

scholarly journals Sexual selection and magic traits in speciation with gene flow

2012 ◽  
Vol 58 (3) ◽  
pp. 510-516 ◽  
Author(s):  
Maria R. Servedio ◽  
Michael Kopp
Keyword(s):  
Sexual Selection ◽  
Gene Flow ◽  
Reproductive Isolation ◽  
A Priori ◽  
The Subject ◽  
Open Question ◽  
Shed Light ◽  
Magic Traits

Abstract The extent to which sexual selection is involved in speciation with gene flow remains an open question and the subject of much research. Here, we propose that some insight can be gained from considering the concept of magic traits (i.e., traits involved in both reproductive isolation and ecological divergence). Both magic traits and other, “non-magic”, traits can contribute to speciation via a number of specific mechanisms. We argue that many of these mechanisms are likely to differ widely in the extent to which they involve sexual selection. Furthermore, in some cases where sexual selection is present, it may be prone to inhibit rather than drive speciation. Finally, there are a priori reasons to believe that certain categories of traits are much more effective than others in driving speciation. The combination of these points suggests a classification of traits that may shed light on the broader role of sexual selection in speciation with gene flow. In particular, we suggest that sexual selection can act as a driver of speciation in some scenarios, but may play a negligible role in potentially common categories of magic traits, and may be likely to inhibit speciation in common categories of non-magic traits.

Sign in / Sign up

Export Citation Format

Share Document