0000000000017596
AUTHOR
Noora Poikela
Strength of sexual and postmating prezygotic barriers varies between sympatric populations with different histories and species abundances.
The impact of different reproductive barriers on species or population isolation may vary in different stages of speciation depending on evolutionary forces acting within species and through species' interactions. Genetic incompatibilities between interacting species are expected to reinforce prezygotic barriers in sympatric populations and lead to cascade reinforcement between conspecific populations living within and outside the areas of sympatry. We tested these predictions and studied whether and how the strength and target of reinforcement between Drosophila montana and Drosophila flavomontana vary between sympatric populations with different histories and species abundances. All barri…
Experimental introgression in Drosophila : Asymmetric postzygotic isolation associated with chromosomal inversions and an incompatibility locus on the X chromosome
Interspecific gene flow (introgression) is an important source of new genetic variation, but selection against it can reinforce reproductive barriers between interbreeding species. We used an experimental approach to trace the role of chromosomal inversions and incompatibility genes in preventing introgression between two partly sympatric Drosophila virilis group species, D. flavomontana and D. montana. We backcrossed F1 hybrid females from a cross between D. flavomontana female and D. montana male with the males of the parental species for two generations and sequenced pools of parental strains and their reciprocal 2nd generation backcross (BC2mon and BC2fla) females. Contrasting the obser…
Adaptation and ecological speciation in seasonally varying environments at high latitudes: Drosophila virilis group
Living in high latitudes and altitudes sets specific requirements on species’ ability to forecast seasonal changes and to respond to them in an appropriate way. Adaptation into diverse environmental conditions can also lead to ecological speciation through habitat isolation or by inducing changes in traits that influence assortative mating. In this review, we explain how the unique time-measuring systems of Drosophila virilis group species have enabled the species to occupy high latitudes and how the traits involved in species reproduction and survival exhibit strong linkage with latitudinally varying photoperiodic and climatic conditions. We also describe variation in reproductive barriers…
Strength of sexual and postmating prezygotic barriers varies between sympatric populations with different histories and species abundances
The impact of different reproductive barriers on species or population isolation may vary in different stages of speciation depending on evolutionary forces acting within species and through species’ interactions. Genetic incompatibilities between interacting species are expected to reinforce prezygotic barriers in sympatric populations and lead to cascade reinforcement between conspecific populations living within and outside the areas of sympatry. We tested these predictions and studied whether and how the strength and target of reinforcement between Drosophila montana and Drosophila flavomontana vary between sympatric populations with different histories and species abundances. All barri…
Reinforcement targets sexual or postmating prezygotic reproductive barriers depending on species abundance and population history
AbstractThe impact of different reproductive barriers on species or population isolation may vary in different stages of speciation depending on evolutionary forces acting within species and through species’ interactions. Genetic incompatibilities between interacting species are expected to reinforce prezygotic barriers in sympatric populations and create character displacement between conspecific populations living within and outside the area of sympatry. The outcome of reinforcement has been suggested to be affected by the strength of postzygotic barriers, the history of species coexistence, and the impact of species abundancies on females’ discrimination against heterospecific males. We …
Additional file 1 of Multiple paths to cold tolerance: the role of environmental cues, morphological traits and the circadian clock gene vrille
Additional file 1: Table S1. Information on fly collecting sites and years, and the exact coordinates (latitude, longitude) and altitudes for each collecting site. Table S2. A List of 19 bioclimatic variables used in the PCA (WorldClim database v2.1, 2.5 min spatial resolutions; current data 1970–2000; Fick and Hijmans 2017; www.worldclim.org ). Table S3. 19 bioclimatic variables for each site were extracted from WorldClim database v2.1. Table S4. Principal components with their variance, cumulative variance and Eigenvalues. Table S5. Contributions (loadings) of the altitude and 19 bioclimatic variables on the Principal Component (PC). Table S6. The best-fit model for CCRT, CTmin, body colo…
Multiple paths to cold tolerance: the role of environmental cues, morphological traits and the circadian clock gene vrille
AbstractBackgroundTracing the association between insect cold tolerance and latitudinally and locally varying environmental conditions, as well as key morphological traits and molecular mechanisms, is essential for understanding the processes involved in adaptation. We explored these issues in two closely-related species, Drosophila montana and Drosophila flavomontana, originating from diverse climatic locations across several latitudes on the coastal and mountainous regions of North America. We also investigated the association between sequence variation in one of the key circadian clock genes, vrille, and cold tolerance in both species. Finally, we studied the impact of vrille on fly cold…
Additional file 1 of Multiple paths to cold tolerance: the role of environmental cues, morphological traits and the circadian clock gene vrille
Additional file 1: Table S1. Information on fly collecting sites and years, and the exact coordinates (latitude, longitude) and altitudes for each collecting site. Table S2. A List of 19 bioclimatic variables used in the PCA (WorldClim database v2.1, 2.5 min spatial resolutions; current data 1970–2000; Fick and Hijmans 2017; www.worldclim.org ). Table S3. 19 bioclimatic variables for each site were extracted from WorldClim database v2.1. Table S4. Principal components with their variance, cumulative variance and Eigenvalues. Table S5. Contributions (loadings) of the altitude and 19 bioclimatic variables on the Principal Component (PC). Table S6. The best-fit model for CCRT, CTmin, body colo…