More Like this

1. Multiple strong postmating and intrinsic postzygotic reproductive barriers isolate florally diverse species of Jaltomata (Solanaceae): REPRODUCTIVE ISOLATION IN JALTOMATA

   https://doi.org/10.1111/evo.13253  

   Kostyun, Jamie L. ; Moyle, Leonie C. ( June 2017 , Evolution)
2. Prezygotic reproductive barriers in precopulatory behavior of tidepool copepod species

   https://doi.org/10.1093/evolut/qpad135  

   Tsuboko-Ishii, Satomi ; Burton, Ronald S. ; Sotka, ed., Erik ; Zelditch, ed., Miriam ( July 2023 , Evolution)

   Complexity in prezygotic mating behavior can contribute to the emergence of sexual incompatibility and reproductive isolation. In this study, we performed behavioral tests with two tidepool copepod species of the genus Tigriopus to explore the possibility of precopulatory behavioral isolation. We found that interspecific mating attempts failed prior to genital contact, and that this failure occurred at different behavioral steps between reciprocal pairings. Our results suggest that prezygotic barriers may exist at multiple points of the behavioral process on both male and female sides, possibly due to interspecific differences in mate-recognition cues used at those “checkpoints.” While many copepod species are known to show unique precopulatory mate-guarding behavior, the potential contribution of prezygotic behavioral factors to their isolation is not widely recognized. The pattern of sequential mate-guarding behaviors may have allowed the diversification of precopulatory communication and contributed to the evolutionary diversity of the Tigriopus copepods.

    

   more » « less
3. Along the speciation continuum: Quantifying intrinsic and extrinsic isolating barriers across five million years of evolutionary divergence in California jewelflowers: REPRODUCTIVE ISOLATION AND GENETIC DISTANCE

   https://doi.org/10.1111/evo.13477  

   Christie, Kyle ; Strauss, Sharon Y. ( May 2018 , Evolution)
4. The effects of heterospecific mating frequency on the strength of cryptic reproductive barriers

   https://doi.org/10.1111/jeb.13495  

   Larson, Erica L. ; Brassil, Margaret M. ; Maslan, Jonathan ; Juárez, Danielle ; Lilagan, Flordeliza ; Tipton, Hallie ; Schweitzer, Andrew ; Skillman, Joe ; Monsen‐Collar, Kirsten J. ; Peterson, Merrill A. ( June 2019 , Journal of Evolutionary Biology)

   Heterospecific mating frequency is critical to hybrid zone dynamics and can directly impact the strength of reproductive barriers and patterns of introgression. The effectiveness of post‐mating prezygotic (PMPZ) reproductive barriers, which include reduced fecundity via heterospecific matings and conspecific sperm precedence, may depend on the number, identity and order of mates. Studies ofPMPZbarriers suggest that they may be important in many systems, but whether these barriers are effective at realistic heterospecific mating frequencies has not been tested. Here, we evaluate the strength of cryptic reproductive isolation in two leaf beetles (Chrysochus auratusandC. cobaltinus) in the context of a range of heterospecific mating frequencies observed in natural populations. We found both species benefited from multiple matings, but the benefits were greater inC. cobaltinusand extended to heterospecific matings. We found thatPMPZbarriers greatly limited hybrid production byC. auratusfemales with moderate heterospecific mating frequencies, but that their effectiveness diminished at higher heterospecific mating frequencies. In contrast, there was no evidence forPMPZbarriers inC. cobaltinusfemales at any heterospecific mating frequency. We show that integrating realistic estimates of cryptic isolation with information on relative abundance and heterospecific mating frequency in the field substantially improves our understanding of the strong directional bias in F1 production previously documented in theChrysochushybrid zone. Our results demonstrate that heterospecific mating frequency is critical to understanding the impact of cryptic post‐copulatory barriers on hybrid zone structure and dynamics, and that future studies of such barriers should incorporate field‐relevant heterospecific mating frequencies.

    

   more » « less
5. Intergeneric hybrids inform reproductive isolating barriers in the Antarctic icefish radiation

   https://doi.org/10.1038/s41598-019-42354-z  

   Desvignes, Thomas ; Le François, Nathalie R. ; Goetz, Laura C. ; Smith, Sierra S. ; Shusdock, Kathleen A. ; Parker, Sandra K. ; Postlethwait, John H. ; Detrich, III., H. William ( April 2019 , Scientific Reports)

   Interspecific hybridization or barriers to hybridization may have contributed to the diversification of Antarctic icefishes (Channichthyidae), but data supporting these hypotheses is scarce. To understand the potential for hybridization and to investigate reproductive isolating mechanisms among icefish species, we performedin vitrofertilization experiments using eggs from a female blackfin icefishChaenocephalus aceratusand sperm from a male of another genera, the ocellated icefishChionodraco rastrospinosus. Sequencing of genomic and mitochondrial DNA confirmed the intergeneric hybrid nature of resulting embryos which successfully developed and hatched as active larvae at about four and a half months during the Antarctic winter. This result demonstrates the compatibility of gametes of these two species and the viability of resulting zygotes and larvae. Due to logistic constraints and the slow developmental rate of icefishes, we could not test for long-term hybrid viability, fertility, fitness, or hybrid breakdown. Analysis of our fishing records and available literature, however, suggests that the strongest barriers to hybridization among parapatric icefish species are likely to be behavioral and characterized by assortative mating and species-specific courtship and nesting behaviors. This conclusion suggests that, in long-lived fish species with late sexual maturity and high energetic investment in reproduction like icefishes, pre-mating barriers are energetically more efficient than post-mating barriers to prevent hybridization.

    

   more » « less