scholarly journals HISTORICAL SEPARATION AND PRESENT GENE FLOW THROUGH A ZONE OF SECONDARY CONTACT IN PONDEROSA PINE

Evolution ◽  
1999 ◽  
Vol 53 (3) ◽  
pp. 769-776 ◽  
Author(s):  
Robert G. Latta ◽  
Jeffry B. Mitton
Keyword(s):  
Gene Flow ◽  
Ponderosa Pine ◽  
Secondary Contact ◽  
Flow Through ◽  
Present Gene

scholarly journals Genomic impacts of chromosomal inversions in parapatric Drosophila species

2012 ◽  
Vol 367 (1587) ◽  
pp. 422-429 ◽  
Author(s):  
Suzanne E. McGaugh ◽  
Mohamed A. F. Noor
Keyword(s):  
Gene Flow ◽  
Secondary Contact ◽  
Chromosome 2 ◽  
Chromosomal Inversions ◽  
The Face ◽  
Flow Through ◽  
Drosophila Persimilis ◽  
Suppressed Recombination ◽  
Or Gene ◽  
Double Crossovers

Chromosomal inversions impact genetic variation and facilitate speciation in part by reducing recombination in heterokaryotypes. We generated multiple whole-genome shotgun sequences of the parapatric species pair Drosophila pseudoobscura and Drosophila persimilis and their sympatric outgroup ( Drosophila miranda ) and compared the average pairwise differences for neutral sites within, just outside and far outside of the three large inversions. Divergence between D. pseudoobscura and D. persimilis is high inside the inversions and in the suppressed recombination regions extending 2.5 Mb outside of inversions, but significantly lower in collinear regions further from the inversions. We observe little evidence of decreased divergence predicted to exist in the centre of inversions, suggesting that gene flow through double crossovers or gene conversion is limited within the inversion, or selection is acting within the inversion to maintain divergence in the face of gene flow. In combination with past studies, we provide evidence that inversions in this system maintain areas of high divergence in the face of hybridization, and have done so for a substantial period of time. The left arm of the X chromosome and chromosome 2 inversions appear to have arisen in the lineage leading to D. persimilis approximately 2 Ma, near the time of the split of D. persimilis–D. pseudoobscura–D. miranda , but likely fixed within D. persimilis much more recently, as diversity within D. persimilis is substantially reduced inside and near these two inversions. We also hypothesize that the inversions in D. persimilis may provide an empirical example of the ‘mixed geographical mode’ theory of inversion origin and fixation, whereby allopatry and secondary contact both play a role.

High gene flow through pollen partially compensates spatial limited gene flow by seeds for a Neotropical tree in forest conservation and restoration areas

2021 ◽  
Author(s):  
Patricia Sanae Sujii ◽  
Evandro Vagner Tambarussi ◽  
Carolina Grando ◽  
Ellida de Aguiar Silvestre ◽  
João Paulo Gomes Viana ◽  
...  
Keyword(s):  
Gene Flow ◽  
Forest Conservation ◽  
Neotropical Tree ◽  
High Gene Flow ◽  
High Gene ◽  
Limited Gene Flow ◽  
Flow Through

Asymmetric acoustic signal recognition led to asymmetric gene flow between two parapatric frogs

2020 ◽  
Author(s):  
Yu-Wei Hsiao ◽  
Hui-Yun Tseng ◽  
Hung Ngoc Nguyen ◽  
Si-Min Lin
Keyword(s):  
Gene Flow ◽  
Contact Region ◽  
Character Displacement ◽  
Secondary Contact ◽  
Genetic Introgression ◽  
Genetic Integrity ◽  
Signal Recognition ◽  
Reproductive Character Displacement ◽  
Reproductive Character ◽  
Behavioural Experiments

Abstract Correct discrimination between courtship signals could help to maintain genetic integrity between closely related species. However, asymmetric usage of signals might cause asymmetric gene flow across the contact zone. Buergeria choui and B. otai are sibling-species with a parapatric distribution pattern in Taiwan, having two narrow contact zones on the east and west sides of the island. Combining behavioural experiments with genome-wide RAD-seq analyses, we test whether the ability of signal recognition influences genetic introgression across their species boundary. The playback experiments show that all B. choui populations respond strongest to their own ‘cricket’ trills, while the western population of B. otai have evolved a strong level of reproductive character displacement by showing the inclusive usage of the unique ‘chicken’ signals. In contrast, the eastern B. otai population uses both ‘chicken’ and ‘cricket’ trills, and has a stronger preference for the latter. The weak reproductive character displacement in the eastern population has led to asymmetry genetic introgression from B. choui toward B. otai. Our results support the prediction that a more specialized signal-user, compared to its sibling, generalized signal-user, might have a higher probability of maintaining their genetic integrity in the secondary contact region.

scholarly journals Secondary contact followed by gene flow between divergent mitochondrial lineages of a widespread Neotropical songbird (Zonotrichia capensis)

2014 ◽  
Vol 111 (4) ◽  
pp. 863-868 ◽  
Author(s):  
Leonardo Campagna ◽  
Cecilia Kopuchian ◽  
Pablo L. Tubaro ◽  
Stephen C. Lougheed
Keyword(s):  
Gene Flow ◽  
Secondary Contact ◽  
Zonotrichia Capensis

Resource partitioning as a factor limiting gene flow in hybridizing populations of Dolly Varden char (Salvelinus malma) and bull trout (Salvelinus confluentus)

2001 ◽  
Vol 58 (10) ◽  
pp. 2037-2047 ◽  
Author(s):  
John Hagen ◽  
Eric B Taylor
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Secondary Contact ◽  
Life History Stage ◽  
Bull Trout ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Salvelinus Confluentus ◽  
Dolly Varden Char ◽  
Northwestern North America

Dolly Varden char (Salvelinus malma) and bull trout (Salvelinus confluentus) hybridize in areas of secondary contact in northwestern North America but maintain their genetic integrity in spite of gene flow. We examined juvenile stream ecology and adult reproductive ecology of these species in sympatry to test for specializations to alternative niches that may act as a basis for natural selection against hybrids. Juvenile Dolly Varden occupied deeper, faster water and foraged more during daytime in the drift, whereas bull trout used shallower, slower water and made more nighttime foraging attempts towards the substrate. The species showed extensive diet overlap (Schoener's index = 0.7–0.9), and we found evidence for density compensation between species among sites. Our results suggest no obvious basis for selection against hybrids at the juvenile stream-rearing life-history stage. Bull trout, however, are adfluvial, whereas Dolly Varden are permanent stream residents. Bull trout are also much larger at maturity (50–80 cm vs. 12–15 cm) and build redds in faster, deeper water using larger substrate sizes. Consequently, hybrid genotypes may be selected against in these alternative life-history niches or during reproduction owing to their intermediate size at maturity and size-dependent spawning habitat use and mate choice.

Playbacks revisited: asymmetry in behavioural response across an acoustic boundary between two parapatric bird species

Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1933-1951 ◽  
Author(s):  
Tamsin Burbidge ◽  
Thari Parson ◽  
Paula C. Caycedo-Rosales ◽  
Carlos Daniel Cadena ◽  
Hans Slabbekoorn
Keyword(s):  
Gene Flow ◽  
Response Pattern ◽  
Bird Species ◽  
Elevational Gradient ◽  
High Elevation ◽  
Secondary Contact ◽  
Potential Contribution ◽  
Asymmetric Response ◽  
Singing Style ◽  
The Impact

Behavioural barriers to gene flow can play a key role in speciation and hybridisation. Birdsong is well-known for its potential contribution to such behavioural barriers as it may affect gene flow through an effect on territorial and mating success across population boundaries. Conspecific recognition and heterospecific discrimination of acoustic variation can prevent or limit hybridization in areas where closely related species meet. Here we tested the impact of song differences on territorial response levels between two adjacent Henicorhina wood-wren species along an elevational gradient in Colombia. In an earlier study, playback results had revealed an asymmetric response pattern, with low-elevation H. leucophrys bangsi responding strongly to any conspecific or heterospecific song variant, whereas high-elevation H. anachoreta birds discriminated, responding more strongly to their own songs than to those of bangsi. However, in that study we could not exclude a role for relative familiarity to the song stimuli. In the current study we confirm the asymmetric response pattern with song stimuli recorded close to and on both sides of the distinct acoustic boundary. Furthermore, we also show a previously unnoticed divergence in singing style between these two wood-wren species, which may contribute to an acoustically guided barrier to hybridization in this secondary contact zone.

scholarly journals Extensive introgression despite Haldane’s rule: insights from grasshopper hybrid zones

2021 ◽  
Author(s):  
Linda Hagberg ◽  
Enrique Celemin ◽  
Iker Irisarri ◽  
Oliver Hawlitschek ◽  
J L Bella ◽  
...  
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Male Sterility ◽  
Secondary Contact ◽  
Hybrid Zones ◽  
Hybrid Male ◽  
Hybrid Male Sterility ◽  
Haldane’S Rule ◽  
Haldane's Rule ◽  
Species Formation

Although the process of species formation is notoriously idiosyncratic, the observation of pervasive patterns of reproductive isolation across species pairs suggests that generalities, or “rules”, underlie species formation in all animals. Haldane’s rule states that whenever a sex is absent, rare or sterile in a cross between two taxa, that sex is usually the heterogametic sex. Yet, understanding how Haldane’s rule first evolves and whether it is associated to genome wide barriers to gene flow remains a challenging task because this rule is usually studied in highly divergent taxa that no longer hybridize in nature. Here, we address these questions using the meadow grasshopper Pseudochorthippus parallelus where populations that readily hybridize in two natural hybrid zones show hybrid male sterility in laboratorial crosses. Using mitochondrial data, we infer that such populations have diverged some 100,000 years ago, surviving multiple glacial periods in isolated Pleistocenic refugia. Nuclear data shows that secondary contact has led to extensive introgression throughout the species range, including between populations showing hybrid male sterility. We find repeatable patterns of genomic differentiation across the two hybrid zones, yet such patterns are consistent with shared genomic constraints across taxa rather than their role in reproductive isolation. Together, our results suggest that Haldane’s rule can evolve relatively quickly within species, particularly when associated to strong demographic changes. At such early stages of species formation, hybrid male sterility still permits extensive gene flow, allowing future studies to identify genomic regions associated with reproductive barriers.

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