Role of selection and gene flow in population differentiation at the edge vs. interior of the species range differing in climatic conditions

2016 ◽  
Vol 25 (7) ◽  
pp. 1449-1464 ◽  
Author(s):  
S. Volis ◽  
D. Ormanbekova ◽  
I. Shulgina
Keyword(s):  
Gene Flow ◽  
Population Differentiation ◽  
Climatic Conditions ◽  
Species Range

scholarly journals Gene flow on ice: the role of sea ice and whaling in shaping Holarctic genetic diversity and population differentiation in bowhead whales (Balaena mysticetus)

2012 ◽  
Vol 2 (11) ◽  
pp. 2895-2911 ◽  
Author(s):  
S. Elizabeth Alter ◽  
Howard C. Rosenbaum ◽  
Lianne D. Postma ◽  
Peter Whitridge ◽  
Cork Gaines ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Sea Ice ◽  
Population Differentiation ◽  
Balaena Mysticetus ◽  
Bowhead Whales

scholarly journals Characteristics of Phomopsis juglandina (Sacc.) Hohn. Associated with Dieback of Walnut in the Climatic Conditions of Southern Romania

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin
Keyword(s):  
Growth Temperature ◽  
Potential Evapotranspiration ◽  
Optimal Growth ◽  
Climatic Conditions ◽  
Cultural Characteristics ◽  
Optimal Growth Temperature ◽  
Conidial State ◽  
Optimal Ph

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

scholarly journals Molecular Signatures of Reticulate Evolution within the Complex of European Pine Taxa

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak
Keyword(s):  
Gene Flow ◽  
Reticulate Evolution ◽  
Modeling Framework ◽  
Closely Related Species ◽  
Interspecific Gene Flow ◽  
Nucleotide Sequence Variation ◽  
History Of ◽  
Best Fitting ◽  
Species Integrity

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

Patterns of population differentiation in annual killifishes from the Paraná-Uruguay-La Plata Basin: the role of vicariance and dispersal

2012 ◽  
Vol 39 (9) ◽  
pp. 1707-1719 ◽  
Author(s):  
Graciela García ◽  
Verónica Gutiérrez ◽  
Julia Vergara ◽  
Pablo Calviño ◽  
Alejandro Duarte ◽  
...  
Keyword(s):  
Population Differentiation ◽  
La Plata ◽  
La Plata Basin

scholarly journals Gene flow increases fitness at the warm edge of a species' range

2011 ◽  
Vol 108 (28) ◽  
pp. 11704-11709 ◽  
Author(s):  
J. P. Sexton ◽  
S. Y. Strauss ◽  
K. J. Rice
Keyword(s):  
Gene Flow ◽  
Species Range

HAS PSYCHOLOGIC MALNUTRITION TAKEN THE PLACE OF RICKETS AND SCURVY IN CONTEMPORARY PEDIATRIC PRACTICE?

PEDIATRICS ◽  
1963 ◽  
Vol 31 (6) ◽  
pp. 909-918
Author(s):  
Nathan B. Talbot
Keyword(s):  
Sixteenth Century ◽  
Lemon Juice ◽  
Climatic Conditions ◽  
Northern Europe ◽  
Scientific Medicine ◽  
Pediatric Practice ◽  
Therapeutic Value ◽  
High Prevalence ◽  
The Baltic

WHILE MEDICAL HISTORIANS cannot provide us with accurate statistics concerning the incidence of rickets and scurvy in centuries past, they leave little room for doubt about the high prevalence of these disorders prior to the advent of modern scientific medicine. Thus, Castiglione has written that in the sixteenth century scurvy raged throughout northern Europe, in Scandinavia, on the shores of the Baltic, and in the interior of Germany. It is interesting to note, however, that Jacques Cartier, whose sailors had been ravaged by scurvy, learned in 1536 from the Indians that the malady could be cured by juices of the almeda tree. This was 200 years before James Lind demonstrated the curative effects of lemon juice in his treatise on scurvy published in 1753 and almost 400 years before ascorbic acid, which was isolated by Szent-Gyorgi in 1928, was recognized to be vitamin C by Waugh and King in 1932. Rickets, likewise, was occurring in a large portion of children prior to the discovery of the existence of vitamin D by Hess, Steinbock, and Windaus in 1918, of its therapeutic value by Mellanby in 1919, of the equivalent role of sunlight by Hess in 1921, and of the chemical composition of the vitamins by Windaus in 1922. But 200 years earlier Friedrick Hoffman had the answer to the control of this disease almost in hand. He attached much importance to climatic conditions as a factor in rickets, noting that if anything is specially powerful in producing this affliction, it is a surrounding atmosphere of cold foggy air. He cited as striking evidence of this the famous emporium of England, London, which he found to be specially apt to produce and foster this disease.

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