scholarly journals When hybrids are not hybrids: a case study of a putative hybrid zone betweenCattleya coccineaandC. brevipedunculata(Orchidaceae)

2016 ◽  
Vol 181 (4) ◽  
pp. 621-639 ◽  
Author(s):  
Bárbara S. S. Leal ◽  
Cleber J. N. Chaves ◽  
Samantha Koehler ◽  
Eduardo L. Borba
Keyword(s):  
Hybrid Zone ◽  
Putative Hybrid

scholarly journals Intraspecific Molecular Variation of Allium ursinum (Amaryllidaceae) Across the Border of Two Subspecies Distribution Ranges

2015 ◽  
Vol 57 (1) ◽  
pp. 31-43
Author(s):  
Kaja Rola ◽  
Anna Lenart-Boroń ◽  
Piotr Boroń ◽  
Piotr Osyczka
Keyword(s):  
Genetic Variability ◽  
Hybrid Zone ◽  
Mantel Test ◽  
Genetic Group ◽  
Secondary Contact ◽  
Putative Hybrid ◽  
Morphological Pattern ◽  
The Third ◽  
Allium Ursinum ◽  
Distribution Ranges

Abstract The study investigates the genetic differentiation among two subspecies of Allium ursinum L., namely A. ursinum subsp. ursinum and subsp. ucrainicum as well as their putative hybrid that is represented by individuals with intermediate morphology. Inter-Simple Sequence Repeats (ISSR) were applied to determine the status of intermediate morphotypes in terms of their genetic pattern and to assess the level of genetic variability within and between various populations of A. ursinum. The study comprises 144 specimens from nine populations along the east-west transect in Poland, which includes localities of both subspecies and their putative hybrid. Among the examined populations, 48 bands were amplified, of which 45 were found to be polymorphic. The principal coordinate analysis (PCoA), the neighbour-net analysis and Mantel test showed a strong correlation between genetic variability and geographic distance. Analysis of molecular variance (AMOVA) revealed that a greater proportion of total genetic variation resided within populations rather than among them. The Structure Bayesian clustering analysis revealed the presence of three distinct genetic groups within studied populations, where ‘eastern’ genotypes correspond to A. ursinum subsp. ucrainicum, and ‘western’ to subsp. ursinum; whereas the third genetic group has the largest share in the individuals occurring at the border of the distribution ranges of both subspecies. The emergence of the third genetic group is probably an effect of hybridization events occurring within the secondary contact zone. Typical morphologically intermediate populations occur only in a relatively narrow geographical zone, but the hybrid zone revealed by molecular markers is actually much wider than it is suggested by the morphological pattern of individuals. The current distribution pattern of both subspecies of A. ursinum and their hybrid zone is related to the two main directions of postglacial migration of Fagus sylvatica to the area of Poland. The hybrid zone arose as an effect of the secondary contact of two divergent lineages of A. ursinum.

scholarly journals Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos

2019 ◽  
Vol 110 (5) ◽  
pp. 523-534 ◽  
Author(s):  
Brendan J Pinto ◽  
James Titus-McQuillan ◽  
Juan D Daza ◽  
Tony Gamble
Keyword(s):  
Reproductive Isolation ◽  
Hybrid Zone ◽  
Sequence Data ◽  
Strong Support ◽  
Climatic Variables ◽  
Putative Hybrid ◽  
Hybrid Zones ◽  
Intermediate Phenotypes ◽  
Genetic Mechanisms ◽  
Stable Hybrid

Abstract Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone between Sphaerodactylus nicholsi and Sphaerodactylus townsendi in Puerto Rico, initially described in 1984. First, we addressed discrepancies in the literature on the validity of both species. Second, we sampled a 10-km-wide transect across the putative hybrid zone and tested explicit predictions about its dynamics using cline models. Third, we investigated potential causes for the hybrid zone using species distribution modeling and simulations; namely, whether unique climatic variables within the hybrid zone might elicit selection for intermediate phenotypes. We find strong support for the species-level status of each species and no evidence of movement, or unique climatic variables near the hybrid zone. We suggest that this narrow hybrid zone is geographically stable and is maintained by a combination of dispersal and selection. Thus, this work has identified an extant model system within geckos that that can be used for future investigations detailing genetic mechanisms of reproductive isolation in an understudied vertebrate group.

Can we continue to neglect genomic variation in introgression rates when inferring the history of speciation? A case study in a Mytilus hybrid zone

2014 ◽  
Vol 27 (8) ◽  
pp. 1662-1675 ◽  
Author(s):  
C. Roux ◽  
C. Fraïsse ◽  
V. Castric ◽  
X. Vekemans ◽  
G. H. Pogson ◽  
...  
Keyword(s):  
Hybrid Zone ◽  
Genomic Variation ◽  
History Of

scholarly journals Molecular evidence and ecological niche modeling reveal an extensive hybrid zone among three Bursera species (section Bullockia)

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260382
Author(s):  
Eduardo Quintero Melecio ◽  
Yessica Rico ◽  
Andrés Lira Noriega ◽  
Antonio González Rodríguez
Keyword(s):  
Interspecific Hybridization ◽  
Hybrid Zone ◽  
Dna Sequences ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Molecular Data ◽  
Niche Modeling ◽  
Hybrid Origin ◽  
Putative Hybrid ◽  
Molecular Evidence

The genus Bursera, includes ~100 shrub and trees species in tropical dry forests with its center of diversification and endemism in Mexico. Morphologically intermediate individuals have commonly been observed in Mexican Bursera in areas where closely related species coexist. These individuals are assumed to result from interspecific hybridization, but no molecular evidence has supported their hybrid origins. This study aimed to investigate the existence of interspecific hybridization among three Mexican Bursera species (Bullockia section: B. cuneata, B. palmeri and B. bipinnata) from nine populations based on DNA sequences (three nuclear and four chloroplast regions) and ecological niche modeling for three past and two future scenario projections. Results from the only two polymorphic nuclear regions (PEPC, ETS) supported the hybrid origin of morphologically intermediate individuals and revealed that B. cuneata and B. bipinnata are the parental species that are genetically closer to the putative hybrids. Ecological niche modeling accurately predicted the occurrence of putative hybrid populations and showed a potential hybrid zone extending in a larger area (74,000 km2) than previously thought. Paleo-reconstructions showed a potential hybrid zone existing from the Last Glacial Maximum (~ 21 kya) that has increased since the late Holocene to the present. Future ecological niche projections show an increment of suitability of the potential hybrid zone for 2050 and 2070 relative to the present. Hybrid zone changes responded mostly to an increase in elevational ranges. Our study provides the first insight of an extensive hybrid zone among three Mexican Bursera species based on molecular data and ecological niche modeling.

scholarly journals A hybrid zone of the genus Ctenomys: a case study in southern Brazil

2012 ◽  
Vol 35 (4 suppl 1) ◽  
pp. 990-997 ◽  
Author(s):  
Camila S. Castilho ◽  
Adriana Gava ◽  
Thales R.O. de Freitas
Keyword(s):  
Hybrid Zone ◽  
Southern Brazil

scholarly journals Inference of allelic dosages and inheritance modes in tetraploids: a case study in Betula apoiensis with a putative hybrid origin

2014 ◽  
Vol 63 (1-6) ◽  
pp. 159-168
Author(s):  
Teruyoshi Nagamitsu ◽  
Takayuki Kawahara ◽  
Ayako Kanazashi
Keyword(s):  
Hybrid Origin ◽  
Null Alleles ◽  
Putative Hybrid ◽  
Double Reduction ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Nuclear Microsatellite ◽  
Polymerase Chain ◽  
Mode Of Inheritance

Abstract In tetraploids, inference of allelic dosages and inheritance modes is difficult due to the ambiguous number of allele copies and the variation between disomic and tetrasomic patterns. Considering the biases of amplification and the overlaps of stutter products in polymerase chain reactions, we inferred tetraploid genotypes at three nuclear microsatellite loci in progeny arrays from six reciprocal crosses among three parents of Betula apoiensis with a putative hybrid origin. In each cross, we assigned diploid genotypes to gametes on the basis of the tetraploid genotypes of the parents and their progeny and observed the frequencies of the gamete genotypes. Segregation patterns of the observed gamete genotypes indicated few null alleles in the progeny arrays and tetrasomic inheritance with rare double reduction. This mode of inheritance was consistent between genders and between mates in the crosses. This result suggests that our method to infer tetraploid genotypes in nuclear microsatellites is successful in family samples with few null alleles when the amplification biases and the stutter-product overlaps are accessed properly.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Culture and the plasticity of perception

2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann
Keyword(s):  
Cultural Context ◽  
Sensory Experience ◽  
Cultural Learning ◽  
The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

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