scholarly journals Postzygotic Isolation Evolves before Prezygotic Isolation between Fresh and Saltwater Populations of the Rainwater Killifish, Lucania parva

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Genevieve M. Kozak ◽  
Arthur B. Rudolph ◽  
Beatrice L. Colon ◽  
Rebecca C. Fuller
Keyword(s):  
Reproductive Isolation ◽  
Fresh Water ◽  
Salt Water ◽  
Postzygotic Isolation ◽  
Hybrid Inviability ◽  
Prezygotic Isolation ◽  
Divergent Natural Selection ◽  
Postzygotic Barriers ◽  
Species Population ◽  
Stable Populations

Divergent natural selection has the potential to drive the evolution of reproductive isolation. The euryhaline killifish Lucania parva has stable populations in both fresh water and salt water. Lucania parva and its sister species, the freshwater L. goodei, are isolated by both prezygotic and postzygotic barriers. To further test whether adaptation to salinity has led to the evolution of these isolating barriers, we tested for incipient reproductive isolation within L. parva by crossing freshwater and saltwater populations. We found no evidence for prezygotic isolation, but reduced hybrid survival indicated that postzygotic isolation existed between L. parva populations. Therefore, postzygotic isolation evolved before prezygotic isolation in these ecologically divergent populations. Previous work on these species raised eggs with methylene blue, which acts as a fungicide. We found this fungicide distorts the pattern of postzygotic isolation by increasing fresh water survival in L. parva, masking species/population differences, and underestimating hybrid inviability.

scholarly journals Patterns of reproductive isolation in a haplodiploid mite, Amphitetranychus viennensis: prezygotic isolation, hybrid inviability and hybrid sterility

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yukie Sato ◽  
Satoshi Fujiwara ◽  
Martijn Egas ◽  
Tomoko Matsuda ◽  
Tetsuo Gotoh
Keyword(s):  
Reproductive Isolation ◽  
Genetic Distance ◽  
Spider Mite ◽  
Hybrid Sterility ◽  
Fertilization Rate ◽  
Spider Mites ◽  
Reproductive Barriers ◽  
Hybrid Female ◽  
Hybrid Inviability ◽  
Prezygotic Isolation

Abstract Background Evolution of reproductive isolation is an important process, generating biodiversity and driving speciation. To better understand this process, it is necessary to investigate factors underlying reproductive isolation through various approaches but also in various taxa. Previous studies, mainly focusing on diploid animals, supported the prevalent view that reproductive barriers evolve gradually as a by-product of genetic changes accumulated by natural selection by showing a positive relationship between the degree of reproductive isolation and genetic distance. Haplodiploid animals are expected to generate additional insight into speciation, but few studies investigated the prevalent view in haplodiploid animals. In this study, we investigate whether the relationship also holds in a haplodiploid spider mite, Amphitetranychus viennensis (Zacher). Results We sampled seven populations of the mite in the Palaearctic region, measured their genetic distance (mtDNA) and carried out cross experiments with all combinations. We analyzed how lack of fertilization rate (as measure of prezygotic isolation) as well as hybrid inviability and hybrid sterility (as measures of postzygotic isolation) varies with genetic distance. We found that the degree of reproductive isolation varies among cross combinations, and that all three measures of reproductive isolation have a positive relationship with genetic distance. Based on the mtDNA marker, lack of fertilization rate, hybrid female inviability and hybrid female sterility were estimated to be nearly complete (99.0–99.9% barrier) at genetic distances of 0.475–0.657, 0.150–0.209 and 0.145–0.210, respectively. Besides, we found asymmetries in reproductive isolation. Conclusions The prevalent view on the evolution of reproductive barriers is supported in the haplodiploid spider mite we studied here. According to the estimated minimum genetic distance for total reproductive isolation in parent population crosses in this study and previous work, a genetic distance of 0.15–0.21 in mtDNA (COI) appears required for speciation in spider mites. Variations and asymmetries in the degree of reproductive isolation highlight the importance of reinforcement of prezygotic reproductive isolation through incompatibility and the importance of cytonuclear interactions for reproductive isolation in haplodiploid spider mites.

scholarly journals Patterns of reproductive isolation in a haplodiploid mite, Amphitetranychus viennensis: prezygotic isolation, hybrid inviability and hybrid sterility

2021 ◽  
Author(s):  
Yukie Sato ◽  
Satoshi Fujiwara ◽  
Martijn Egas ◽  
Tomoko Matsuda ◽  
Tetsuo Gotoh
Keyword(s):  
Reproductive Isolation ◽  
Genetic Distance ◽  
Spider Mite ◽  
Hybrid Sterility ◽  
Fertilization Rate ◽  
Spider Mites ◽  
Reproductive Barriers ◽  
Hybrid Female ◽  
Hybrid Inviability ◽  
Prezygotic Isolation

Abstract Background Evolution of reproductive isolation is an important process, generating biodiversity and driving speciation. To better understand this process, it is necessary to investigate factors underlying reproductive isolation through various approaches but also in various taxa. Previous studies, mainly focusing on diploid animals, supported the prevalent view that reproductive barriers evolve gradually as a by-product of genetic changes accumulated by natural selection by showing a positive relationship between the degree of reproductive isolation and genetic distance. Haplodiploid animals are expected to generate additional insight into speciation, but few studies investigated the prevalent view in haplodiploid animals. In this study, we investigate whether the relationship also holds in a haplodiploid spider mite, Amphitetranychus viennensis (Zacher). Results We sampled seven populations of the mite in the Palaearctic region, measured their genetic distance (mtDNA) and carried out cross experiments with all combinations. We analyzed how lack of fertilization rate (as measure of prezygotic isolation) as well as hybrid inviability and hybrid sterility (as measures of postzygotic isolation) varies with genetic distance. We found that the degree of reproductive isolation varies among cross combinations, and that all three measures of reproductive isolation have a positive relationship with genetic distance. Based on the mtDNA marker, lack of fertilization rate, hybrid female inviability and hybrid female sterility were estimated to be nearly complete (99.0–99.9% barrier) at genetic distances of 0.475–0.657, 0.150–0.209 and 0.138–0.204, respectively. Conclusions The prevalent view on the evolution of reproductive barriers is supported in the haplodiploid spider mite we studied here. According to the estimated minimum genetic distance for total reproductive isolation in parent population crosses in this and previous studies, a genetic distance of 0.152–0.210 in mtDNA (COI) appears required for speciation in spider mites. Due to a lack of hybrid males, we could not address Haldane’s rule, which can be extended to haplodiploids, even though we focused on a young diverging group of spider mites. Our results highlight the importance of cytonuclear interactions for reproductive isolation in haplodiploid spider mites.

scholarly journals The rate of evolution of postmating-prezygotic reproductive isolation in Drosophila

2017 ◽  
Author(s):  
David A. Turissini ◽  
Joseph A. McGirr ◽  
Sonali S. Patel ◽  
Jean R. David ◽  
Daniel R. Matute
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Biological Species ◽  
Biological Species Concept ◽  
Premating Isolation ◽  
Hybrid Inviability ◽  
Systematic Analysis ◽  
Rates Of Evolution ◽  
Postzygotic Barriers

ABSTRACTReproductive isolation (RI) is an intrinsic aspect of species, as described in the Biological Species Concept. For that reason, the identification of the precise traits and mechanisms of RI, and the rates at which they evolve, is crucial to understanding how species originate and persist. Nonetheless, precise measurements of the magnitude of reproductive isolation are rare. Previous work has measured the rates of evolution of prezygotic and postzygotic barriers to gene flow, yet no systematic analysis has carried out the study of the rates of evolution of postmating-prezygotic (PMPZ) barriers. We systematically measured the magnitude of two barriers to gene flow that act after mating occurs but before zygotic fertilization and also measured a premating (female mating rate in nonchoice experiments) and two postzygotic barriers (hybrid inviability and hybrid sterility) for all pairwise crosses of species within the Drosophila melanogaster subgroup. Our results indicate that PMPZ isolation evolves faster than hybrid inviability but slower than premating isolation. We also describe seven new interspecific hybrids in the group. Our findings open up a large repertoire of tools that will enable researchers to manipulate hybrids and explore the genetic basis of interspecific differentiation, reproductive isolation, and speciation.

scholarly journals XII. An easy method to distill fresh water from salt water at sea; by Capt. Newland

1772 ◽  
Vol 62 ◽  
pp. 90-92 ◽  
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Easy Method

The materials necessary for this process are the following; a copper or iron pot of 15 or 20 gallons, an empty cask, some sheet lead, a small jar, a few wood-ashes or soap, and billet-wood for fewel.

scholarly journals Differences in offspring size predict the direction of isolation asymmetry between populations of a placental fish

2013 ◽  
Vol 9 (5) ◽  
pp. 20130327 ◽  
Author(s):  
Matthew Schrader ◽  
Rebecca C. Fuller ◽  
Joseph Travis
Keyword(s):  
Reproductive Isolation ◽  
Offspring Size ◽  
Hybrid Inviability ◽  
Haldane’S Rule ◽  
Haldane's Rule ◽  
Asymmetric Pattern ◽  
Heterandria Formosa ◽  
Different Populations ◽  
Selection For

Crosses between populations or species often display an asymmetry in the fitness of reciprocal F 1 hybrids. This pattern, referred to as isolation asymmetry or Darwin's Corollary to Haldane's Rule, has been observed in taxa from plants to vertebrates, yet we still know little about which factors determine its magnitude and direction. Here, we show that differences in offspring size predict the direction of isolation asymmetry observed in crosses between populations of a placental fish, Heterandria formosa . In crosses between populations with differences in offspring size, high rates of hybrid inviability occur only when the mother is from a population characterized by small offspring. Crosses between populations that display similarly sized offspring, whether large or small, do not result in high levels of hybrid inviability in either direction. We suggest this asymmetric pattern of reproductive isolation is due to a disruption of parent–offspring coadaptation that emerges from selection for differently sized offspring in different populations.

scholarly journals MEASUREMENT OF INTERFACE BETWEEN FRESH WATER AND SALT WATER USING ENERGY ABSORPTION CHARACTERISTICS IN MICROWAVE

2010 ◽  
Vol 66 (2) ◽  
pp. 189-195
Author(s):  
Yuji ITO ◽  
Hideki MIYAMOTO ◽  
Masumi KORIYAMA ◽  
Jiro CHIKUSHI ◽  
Masahiro SEGUCHI
Keyword(s):  
Fresh Water ◽  
Energy Absorption ◽  
Salt Water ◽  
Absorption Characteristics

scholarly journals Morphologically cryptic Amazonian bird species pairs exhibit strong postzygotic reproductive isolation

2018 ◽  
Vol 285 (1874) ◽  
pp. 20172081 ◽  
Author(s):  
Paola Pulido-Santacruz ◽  
Alexandre Aleixo ◽  
Jason T. Weir
Keyword(s):  
Reproductive Isolation ◽  
Amazon Basin ◽  
Species Recognition ◽  
Bird Species ◽  
Hybrid Zones ◽  
Hybrid Index ◽  
Postzygotic Isolation ◽  
Genome Wide ◽  
Species Pairs ◽  
Hybrid Classes

We possess limited understanding of how speciation unfolds in the most species-rich region of the planet—the Amazon basin. Hybrid zones provide valuable information on the evolution of reproductive isolation, but few studies of Amazonian vertebrate hybrid zones have rigorously examined the genome-wide underpinnings of reproductive isolation. We used genome-wide genetic datasets to show that two deeply diverged, but morphologically cryptic sister species of forest understorey birds show little evidence for prezygotic reproductive isolation, but substantial postzygotic isolation. Patterns of heterozygosity and hybrid index revealed that hybrid classes with heavily recombined genomes are rare and closely match simulations with high levels of selection against hybrids. Genomic and geographical clines exhibit a remarkable similarity across loci in cline centres, and have exceptionally narrow cline widths, suggesting that postzygotic isolation is driven by genetic incompatibilities at many loci, rather than a few loci of strong effect. We propose Amazonian understorey forest birds speciate slowly via gradual accumulation of postzygotic genetic incompatibilities, with prezygotic barriers playing a less important role. Our results suggest old, cryptic Amazonian taxa classified as subspecies could have substantial postzygotic isolation deserving species recognition and that species richness is likely to be substantially underestimated in Amazonia.

Salt-Water Interface Near a Fresh-Water Canal

1964 ◽  
Vol 90 (6) ◽  
pp. 97-116
Author(s):  
Norbert L. Ackermann ◽  
Pachern Sridurongkatum
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Water Interface ◽  
Water Canal

The use of saline water for irrigating rice in northern Australia

1968 ◽  
Vol 8 (33) ◽  
pp. 491 ◽  
Author(s):  
RW Strickland
Keyword(s):  
Fresh Water ◽  
Saline Water ◽  
Salt Water ◽  
Growth And Yield ◽  
Soluble Salts ◽  
Reproductive Phase ◽  
Panicle Number ◽  
Soil Conductivity ◽  
Restricted Use ◽  
Reproductive Phases

A pot trial to assess the effect of salt water on growth and yield of rice in the Northern Territory of Australia was conducted in 1962-63. Two varieties were irrigated with three levels of salinity for varied durations in either the establishment or reproductive phases. Plant emergence was significantly depressed by soil conductivities in excess of 4 m-mhos/cm at 25�C. The restricted use of up to 3000 p.p.m. total soluble salts from 10 days after emergence and of up to 6000 p.p.m. from 20 days after emergence, followed by fresh water, had no effect on flowering time, vegetative or grain yields. The application of 3000 and 6000 p.p.m. total soluble salts in the reproductive phase reduced mean panicle number and grain yield of both varieties and straw yield of one variety. Use of saline water in the establishment phase followed by fresh water and drainage, reduced soil conductivity. In the reproductive phase it nullified the effect of previous fresh water flushing and tended to increase soil conductivity above original levels.

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