scholarly journals The genetic basis of reproductive isolation: Insights from Drosophila

2005 ◽  
Vol 102 (Supplement 1) ◽  
pp. 6522-6526 ◽  
Author(s):  
H. A. Orr
Keyword(s):  
Reproductive Isolation ◽  
Genetic Basis

The potential for rapid speciation in plants

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 203-210 ◽  
Author(s):  
Mark R. Macnair
Keyword(s):  
Reproductive Isolation ◽  
Genetic Architecture ◽  
Genetic Basis ◽  
Natural Populations ◽  
Direct Result ◽  
Epistatic Interactions ◽  
Genetic Changes ◽  
Rapid Speciation ◽  
Genetic Revolution ◽  
Self Fertilization

Speciation involves both ecological adaptation and reproductive isolation. This paper reviews various ways in which plants could achieve reproductive isolation as a direct result of adaptation to prevailing conditions, particularly through changes in flowering time, the adoption of self-fertilization, and changes in flower morphology so that different pollinators are attracted. These characters are likely to have a relatively simple genetic architecture, and there must frequently be genetic variance for them in natural populations. It is argued that speciation could thus be initiated swiftly in plants, without any need for a "genetic revolution" or the fixation of genes with strongly epistatic interactions. Postmating barriers also often have a simple genetic basis in plants, and so could also evolve swiftly if associated with an adaptive response. The nature of the genetic changes associated with speciation in a number of recent speciation events in Layia, Stephanomeria, and Mimulus is reviewed.Key words: Speciation, adaptation, reproductive isolation.

scholarly journals The Genetic Basis of Prezygotic Reproductive Isolation Between Drosophila santomea and D. yakuba Due to Mating Preference

Genetics ◽  
2006 ◽  
Vol 173 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Amanda J. Moehring ◽  
Ana Llopart ◽  
Susannah Elwyn ◽  
Jerry A. Coyne ◽  
Trudy F. C. Mackay
Keyword(s):  
Reproductive Isolation ◽  
Genetic Basis ◽  
Mating Preference

scholarly journals Sympatric, parapatric or allopatric: the most important way to classify speciation?

2008 ◽  
Vol 363 (1506) ◽  
pp. 2997-3007 ◽  
Author(s):  
Roger K Butlin ◽  
Juan Galindo ◽  
John W Grahame
Keyword(s):  
Reproductive Isolation ◽  
Local Adaptation ◽  
Genetic Basis ◽  
Environmental Gradients ◽  
Sympatric Speciation ◽  
Model System ◽  
Littorina Saxatilis ◽  
The Past ◽  
Intertidal Gastropod

The most common classification of modes of speciation begins with the spatial context in which divergence occurs: sympatric, parapatric or allopatric. This classification is unsatisfactory because it divides a continuum into discrete categories, concentrating attention on the extremes, and it subordinates other dimensions on which speciation processes vary, such as the forces driving differentiation and the genetic basis of reproductive isolation. It also ignores the fact that speciation is a prolonged process that commonly has phases in different spatial contexts. We use the example of local adaptation and partial reproductive isolation in the intertidal gastropod Littorina saxatilis to illustrate the inadequacy of the spatial classification of speciation modes. Parallel divergence in shell form in response to similar environmental gradients in England, Spain and Sweden makes this an excellent model system. However, attempts to demonstrate ‘incipient’ and ‘sympatric’ speciation involve speculation about the future and the past. We suggest that it is more productive to study the current balance between local adaptation and gene flow, the interaction between components of reproductive isolation and the genetic basis of differentiation.

scholarly journals Conspecific sperm precedence is reinforced but sexual selection weakened in sympatric populations ofDrosophila

2016 ◽  
Author(s):  
Dean M. Castillo ◽  
Leonie C. Moyle
Keyword(s):  
Sexual Selection ◽  
Reproductive Isolation ◽  
Sperm Competition ◽  
Competitive Ability ◽  
Genetic Basis ◽  
Direct Selection ◽  
Sperm Precedence ◽  
Sympatric Populations ◽  
Selection For ◽  
The Cost

SUMMARYSexual selection is well recognized as a driver of reproductive isolation between lineages. However, selection for increased reproductive isolation could reciprocally change the outcomes of sexual selection, when these processes share a genetic basis. Direct selection for reproductive isolation occurs in the context of ‘reinforcement’, where selection acts to increase prezygotic barriers to reduce the cost of heterospecific matings. Many studies of reinforcement focus on premating reproductive barriers, however postmating traits-such as conspecific sperm precedence (CSP)-can also respond to reinforcing selection. We tested whether i) CSP responded to reinforcing selection, and ii) this response in sympatric populations altered intraspecific sperm competition (ISC) and the strength of sexual selection, with the sister speciesDrosophila pseudoobscuraandD. persimilis. We used sperm competition experiments to evaluate differences in CSP and ISC between two sympatric and two allopatric populations ofD. pseudoobscura. Using multiple genotypes for each population allowed us to estimate not only patterns of phenotype divergence, but also the opportunity for sexual selection within each population. Consistent with a pattern of reinforcement, the sympatric populations had higher mean CSP. Moreover, ISC was altered in sympatric populations, where we observed decreased average offensive sperm competitive ability against conspecific males, allowing less opportunity for sexual selection to operate within these populations. These data demonstrate that strong reinforcing selection for reproductive isolation can have consequences for sexual selection and sexual interactions within species, in these important postmating sperm competition traits.

scholarly journals The Genetic Basis of Postzygotic Reproductive Isolation Between Drosophila santomea and D. yakuba Due to Hybrid Male Sterility

Genetics ◽  
2006 ◽  
Vol 173 (1) ◽  
pp. 225-233 ◽  
Author(s):  
Amanda J. Moehring ◽  
Ana Llopart ◽  
Susannah Elwyn ◽  
Jerry A. Coyne ◽  
Trudy F. C. Mackay
Keyword(s):  
Reproductive Isolation ◽  
Male Sterility ◽  
Genetic Basis ◽  
Hybrid Male ◽  
Hybrid Male Sterility ◽  
Postzygotic Reproductive Isolation

scholarly journals How Important Are Structural Variants for Speciation?

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1084
Author(s):  
Linyi Zhang ◽  
Radka Reifová ◽  
Zuzana Halenková ◽  
Zachariah Gompert
Keyword(s):  
Reproductive Isolation ◽  
Statistical Methods ◽  
Genetic Basis ◽  
Structural Changes ◽  
Underlying Mechanism ◽  
Structural Variants ◽  
Research Directions ◽  
New Research ◽  
Empirical Approaches

Understanding the genetic basis of reproductive isolation is a central issue in the study of speciation. Structural variants (SVs); that is, structural changes in DNA, including inversions, translocations, insertions, deletions, and duplications, are common in a broad range of organisms and have been hypothesized to play a central role in speciation. Recent advances in molecular and statistical methods have identified structural variants, especially inversions, underlying ecologically important traits; thus, suggesting these mutations contribute to adaptation. However, the contribution of structural variants to reproductive isolation between species—and the underlying mechanism by which structural variants most often contribute to speciation—remain unclear. Here, we review (i) different mechanisms by which structural variants can generate or maintain reproductive isolation; (ii) patterns expected with these different mechanisms; and (iii) relevant empirical examples of each. We also summarize the available sequencing and bioinformatic methods to detect structural variants. Lastly, we suggest empirical approaches and new research directions to help obtain a more complete assessment of the role of structural variants in speciation.

scholarly journals Varying Intensities of Introgression Obscure Incipient Venom-Associated Speciation in the Timber Rattlesnake (Crotalus horridus)

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 782
Author(s):  
Mark J. Margres ◽  
Kenneth P. Wray ◽  
Dragana Sanader ◽  
Preston J. McDonald ◽  
Lauren M. Trumbull ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Genetic Basis ◽  
Spatial Scales ◽  
Demographic History ◽  
Type A ◽  
Ecological Speciation ◽  
Type B ◽  
Crotalus Horridus ◽  
Timber Rattlesnake ◽  
Evolutionary Forces

Ecologically divergent selection can lead to the evolution of reproductive isolation through the process of ecological speciation, but the balance of responsible evolutionary forces is often obscured by an inadequate assessment of demographic history and the genetics of traits under selection. Snake venoms have emerged as a system for studying the genetic basis of adaptation because of their genetic tractability and contributions to fitness, and speciation in venomous snakes can be associated with ecological diversification such as dietary shifts and corresponding venom changes. Here, we explored the neurotoxic (type A)–hemotoxic (type B) venom dichotomy and the potential for ecological speciation among Timber Rattlesnake (Crotalus horridus) populations. Previous work identified the genetic basis of this phenotypic difference, enabling us to characterize the roles geography, history, ecology, selection, and chance play in determining when and why new species emerge or are absorbed. We identified significant genetic, proteomic, morphological, and ecological/environmental differences at smaller spatial scales, suggestive of incipient ecological speciation between type A and type B C. horridus. Range-wide analyses, however, rejected the reciprocal monophyly of venom type, indicative of varying intensities of introgression and a lack of reproductive isolation across the range. Given that we have now established the phenotypic distributions and ecological niche models of type A and B populations, genome-wide data are needed and capable of determining whether type A and type B C. horridus represent distinct, reproductively isolated lineages due to incipient ecological speciation or differentiated populations within a single species.

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