Genetic differentiation of populations of the copepod sea louse Lepeophtheirus salmonis (Krøyer) ectoparasitic on wild and farmed salmonids around the coasts of Scotland: Evidence from RAPD markers

1997 ◽  
Vol 210 (2) ◽  
pp. 251-274 ◽  
Author(s):  
C.D. Todd ◽  
A.M. Walker ◽  
K. Wolff ◽  
S.J. Northcott ◽  
A.F. Walker ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Rapd Markers ◽  
Lepeophtheirus Salmonis ◽  
Genetic Differentiation Of Populations

scholarly journals Population structuring of the endemic black-cheeked gnateater, Conopophaga melanops melanops (Vieillot, 1818) (Aves, Conopophagidae), in the Brazilian Atlantic Forest

2007 ◽  
Vol 67 (4 suppl) ◽  
pp. 867-872 ◽  
Author(s):  
VO. Lunardi ◽  
MR. Francisco ◽  
PM. Galetti Jr.
Keyword(s):  
Genetic Differentiation ◽  
Atlantic Forest ◽  
Rapd Markers ◽  
Nonparametric Test ◽  
Brazilian Atlantic Forest ◽  
Randomly Amplified Polymorphic Dna ◽  
Molecular Variance ◽  
Local Populations ◽  
Population Structuring ◽  
Significant Genetic Divergence

Randomly amplified polymorphic DNA (RAPD) markers were used to analyze genetic differentiation among three populations of the endemic Black-cheeked Gnateater (Conopophaga melanops melanops) within a larger pristine reminiscent of the Brazilian Atlantic Forest. Analyses of molecular variance (AMOVA) (phiST = 0.13149, P < 0.0001) and the nonparametric test for homogeneity of the molecular variance (HOMOVA) (B = 0.32337; P = 0.0019) showed a statistically significant genetic divergence among the three Black-cheeked Gnateater populations in a continuous transect of 250 km. Some hypothetic explanations for these results are the sedentary nature of the species and the historical isolation of the populations in refuges during the Pleistocene. The present results suggest that the local populations were naturally differentiated along the entire original range before the recent process of massive deforestation.

Biochemical Genetic Variation, Growth and Regeneration of the Sea Anemone, Metridium, of British Shores

1985 ◽  
Vol 65 (1) ◽  
pp. 141-157 ◽  
Author(s):  
Ann Bucklin
Keyword(s):  
Genetic Differentiation ◽  
Taxonomic Status ◽  
Sea Anemone ◽  
Sea Anemones ◽  
The United Kingdom ◽  
Metridium Senile ◽  
Genetic Differentiation Of Populations ◽  
Biochemical Genetic ◽  
Enormous Number ◽  
Interesting System

Sessile organisms capable of asexual reproduction may be expected to show much genetic differentiation among local populations: mating between distant individuals is unlikely and genetic drift will contribute to differentiation since habitats can be colonized by one or a few individuals. This study investigates genetic differentiation of populations of the sea anemone Metridium senile (L.) in Great Britain. Individuals of M. senile are sessile and reproduce both sexually, by free-spawning of gametes, and asexually, by regeneration of fragments torn from the pedal disc. Metridium senile is one of the most common and widespread of British sea anemones (Manuel, 1981); reports place it at an enormous number and variety of sites around Britian (unpublished results of surveys by the Underwater Conservation Society of the United Kingdom). The extensive geographic range and variability of the species have confounded attempts to determine the taxonomic status of the ecological and morphological forms, but make it an interesting system for genetic analysis.

scholarly journals Phylogeography of the widespread white-eared hummingbird (Hylocharis leucotis): pre-glacial expansion and genetic differentiation of populations separated by the Isthmus of Tehuantepec

2020 ◽  
Vol 130 (2) ◽  
pp. 247-267
Author(s):  
Luz E Zamudio-Beltrán ◽  
Yuyini Licona-Vera ◽  
Blanca E Hernández-Baños ◽  
John Klicka ◽  
Juan Francisco Ornelas
Keyword(s):  
Genetic Differentiation ◽  
Haplotype Network ◽  
Suitable Habitat ◽  
Glacial Cycles ◽  
Niche Modelling ◽  
Climatic Fluctuations ◽  
History Of ◽  
Genetic Differentiation Of Populations ◽  
Isthmus Of Tehuantepec ◽  
Glacial Expansion

Abstract The Pleistocene glacial cycles had a strong influence on the demography and genetic structure of many species, particularly on northern-latitude taxa. Here we studied the phylogeography of the white-eared hummingbird (Hylocharis leucotis), a widely distributed species of the highlands of Mexico and Central America. Analysis of mitochondrial DNA (mtDNA) sequences was combined with ecological niche modelling (ENM) to infer the demographic and population differentiation scenarios under present and past conditions. Analyses of 108 samples from 11 geographic locations revealed population structure and genetic differentiation among populations separated by the Isthmus of Tehuantepec (IT) and the Motagua-Polochic-Jocotán (MPJ) fault barriers. ENM predicted a widespread distribution of suitable habitat for H. leucotis since the Last Inter Glacial (LIG), but this habitat noticeably contracted and fragmented at the IT. Models for historical dispersal corridors based on population genetics data and ENM revealed the existence of corridors among populations west of the IT; however, the connectivity of populations across the IT has changed little since the LIG. The shallow geographic structure on either side of the isthmus and a star-like haplotype network, combined with the long-term persistence of populations across time based on genetic data and potential dispersal routes, support a scenario of divergence with migration and subsequent isolation and differentiation in Chiapas and south of the MPJ fault. Our findings corroborate the profound effects of Pleistocene climatic fluctuations on the evolutionary history of montane taxa but challenge the generality of expanded suitable habitat (pine-oak forests) during glacial cycles.

Genetic differentiation of populations of Greenlandic Arctic fox

2001 ◽  
Vol 20 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Pia G. Meinke ◽  
Christian M. O. Kapel ◽  
Peter Arctander
Keyword(s):  
Genetic Differentiation ◽  
Arctic Fox ◽  
Genetic Differentiation Of Populations

scholarly journals Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae)

2000 ◽  
Vol 23 (3) ◽  
pp. 639-648 ◽  
Author(s):  
Cecilia Bessega ◽  
Beatriz O. Saidman ◽  
Juan C. Vilardi
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Rapd Markers ◽  
Random Amplified Polymorphic Dna ◽  
Mantel Test ◽  
Prosopis Glandulosa ◽  
Geographical Distance ◽  
Taxonomic Studies

Allozyme and random amplified polymorphic DNA (RAPD) techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm < 1) estimates. When only P. glandulosa populations were analyzed, isozyme data yielded higher gene flow estimates (Nm > 1), in agreement with that expected for conspecific populations. However, in RAPD data the expected reduction in F DT and the increase in Nm were not observed. Correlation between F DT and geographical distance matrices (Mantel test) for all populations was significant (P = 0.02) when based on isozymes, but not so (P = 0.33) when based on RAPDs. No significant associations among genetic and geographical or climatic variables were observed. Two isoenzyme systems (GOT and PRX) enabled us to distinguish between P. glandulosa and P. velutina, but no diagnostic band for recognition of populations or species studied here were detected by RAPD. However, RAPD markers showed higher values for genetic differentiation among conspecific populations of P. glandulosa and a lower coefficient of variation than those obtained from isozymes.

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