Dispersal, Gene Flow, and Allelic Diversity between Local Populations of Thomomys bottae Pocket Gophers in the Coastal Ranges of California

Evolution ◽  
1990 ◽  
Vol 44 (5) ◽  
pp. 1283 ◽  
Author(s):  
Joanne C. Daly ◽  
J. L. Patton
Keyword(s):  
Gene Flow ◽  
Allelic Diversity ◽  
Pocket Gophers ◽  
Local Populations ◽  
Thomomys Bottae

Intact genetic structure and high levels of genetic diversity in bottlenecked sockeye salmon (Oncorhynchus nerka) populations of the Fraser River, British Columbia, Canada

2000 ◽  
Vol 57 (10) ◽  
pp. 1985-1998 ◽  
Author(s):  
Ruth E Withler ◽  
Khai D Le ◽  
R John Nelson ◽  
Kristina M Miller ◽  
Terry D Beacham
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Allelic Diversity ◽  
Lower Proportion ◽  
Fraser River ◽  
Rare Alleles ◽  
Genetic Bottlenecks

Analysis of six microsatellite loci in 5800 sockeye salmon (Oncorhynchus nerka) from 29 Fraser River populations provided little evidence of genetic bottlenecks or mass straying in upper Fraser sockeye salmon resulting from reduced abundances following 1913-1914 rockslides in the Fraser canyon and successive decades of high exploitation. Upper Fraser populations were not characterized by a paucity of rare alleles, a sensitive indicator of populations in which effective size has been recently reduced. Heterozygosity and allelic diversity did not differ consistently between lower and upper Fraser populations. Throughout the watershed, early-migrating populations had lower allelic diversity and a lower proportion of rare alleles than did late-migrating ones. Genetic differentiation between upper and lower Fraser populations and heterogeneity among lower Fraser populations supported the suggestion that Fraser sockeye salmon are descendants of at least two postglacial "races." Variation among lakes within regions was the strongest component of genetic structure, accounting for five times the variation among populations within lakes and more than two times the variation among regions. Extensive historical transplants of eggs and juveniles apparently resulted in lit tle gene flow among regions, but three populations were reestablished or rebuilt as the result of more recent transplants.

Genetic structure of the arboreal squirrels (Glaucomys sabrinus and Tamiasciurus hudsonicus) in the North American Black Hills

2012 ◽  
Vol 90 (9) ◽  
pp. 1191-1200 ◽  
Author(s):  
A.M. Kiesow ◽  
E.M. Monroe ◽  
H.B. Britten
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Management Practices ◽  
Allelic Diversity ◽  
Black Hills ◽  
Tamiasciurus Hudsonicus ◽  
Glaucomys Sabrinus ◽  
Red Squirrel ◽  
Isolated Populations ◽  
Red Squirrels

We selected two isolated mammalian populations, the Black Hills northern flying squirrel ( Glaucomys sabrinus (Shaw, 1801)) and red squirrel ( Tamiasciurus hudsonicus (Erxleben, 1777)), to elucidate their genetic structure. We trapped both squirrels from 2005 to 2007, in three regions of the Black Hills, differing in geology and vegetation, to collect ear samples for genetic analyses. Microsatellite loci (northern flying (9) and red squirrel (13)) were used to examine genetic structure. Data analyses estimated genetic variability, substructure, and gene flow. Northern flying and red squirrel populations have allelic diversity and observed heterozygosity similar to other isolated populations. Each species shows weak substructure from STRUCTURE and GENELAND analyses, suggesting squirrel movements may be inhibited by topography or unsuitable habitat. Recent gene flow estimates from BAYESASS indicate that both species experience some within population gene flow and red squirrels may be more structured than northern flying squirrels because of lower migration rates. Concordant patterns of genetic structure in northern flying and red squirrels indicate that other species’ movements in the Black Hills may be affected by topography and habitat. Because their habitat is isolated in the Black Hills, management practices and conservation measures are recommended to promote viability and survival of each species.

Subsurface Stone Lines, Stone Zones, Artifact-Manuport Layers, and Biomantles Produced by Bioturbation via Pocket Gophers (Thomomys Bottae)

1989 ◽  
Vol 54 (2) ◽  
pp. 370-389 ◽  
Author(s):  
Donald L. Johnson
Keyword(s):  
Laboratory Tests ◽  
Fine Fraction ◽  
Archaeological Site ◽  
Site Formation ◽  
Maximum Diameter ◽  
Field Observations ◽  
Pocket Gophers ◽  
Subsurface Zone ◽  
Thomomys Bottae ◽  
Gravelly Soil

A prominent subsurface zone (layer) of large stones with diameters greater than 6-7 cm occurs in gravelly soil on colluvial aprons in the Lompoc area of California. The soil is mounded and churned by botta pocket gophers (Thomomys bottae). Sedimentological analyses show that the soil within and above the stone zone—and within the gopher mounds—is relatively homogeneous in fine fraction and forms a biomantle. None of the mounds contained stones with long-axis diameters greater than the maximum diameter of gopher burrows, about 6-7 cm. Larger stones gradually subside and form a stone zone. Both field observations and laboratory tests confirm that gopher bioturbation produces stone zones in coarse gravelly soil. This finding, and similar findings in two other recent studies, have important implications for interpreting archaeological site formation, and for interpreting geologic-pedologic processes inasmuch as artifact layers (and nonartifact layers) in some sites entirely may be due to nonanthropic, nongeologic, postdepositional biological agents.

Invited Minireview: Restoring Demographic Processes in Translocated Populations: The Case of Collared Lizards in the Missouri Ozarks Using Prescribed Forest Fires

2007 ◽  
Vol 53 (2) ◽  
pp. 179-196 ◽  
Author(s):  
Alan R. Templeton ◽  
Jennifer L. Neuwald ◽  
Hilary Brazeal ◽  
R. James Robertson
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Habitat Fragmentation ◽  
Forest Fires ◽  
Local Extinction ◽  
Management Policy ◽  
Fire Scar ◽  
Local Populations ◽  
Collared Lizard ◽  
Rocky Habitats

Habitat fragmentation is one of the more important contributors to species endangerment, but one form of fragmentation, here called dispersal fragmentation, can often go unobserved for many years after it has occurred. Many species live in naturally fragmented habitats, but the local populations are interconnected genetically and demographically by dispersal through the environmental matrix in which the habitats are embedded. Because of dispersal, the local populations are not truly fragmented evolutionarily or ecologically. However, when human activities alter the environmental matrix such that dispersal is no longer possible, the population does indeed become fragmented even though they initially are present in the same habitats. An example of dispersal fragmentation via an altered environmental matrix is provided by the eastern collared lizard (Crotaphytus collaris collaris). This lizard lives on open, rocky habitats, called glades, that are embedded in the forests of the Ozarks, a highland region located primarily in Missouri and Arkansas in the USA. Forest fire suppression has reduced this habitat, resulting in severe habitat fragmentation, disruption of gene flow, loss of genetic variation within glade populations, and local extinction without recolonization. Beginning in 1982, glade habitats were restored by clearing and burning in the Peck Ranch area of the Missouri Ozarks, a region where the lizards had gone extinct. Starting in 1984, lizard populations were translocated from other Missouri glades onto restored glades at the Peck Ranch. Although these translocated populations survived well on the restored glades, no movement was detected between glades, some just 50 m apart, and no colonization of nearby restored glades, some just 60 m away, occurred between 1984 and 1993. Fragmentation, lack of colonization, no gene flow, and loss of genetic variation still persisted despite translocation reversing some of the local extinction. Fire scar data from trees and tree stumps indicated that forest fires were common in this area prior to European settlement, so in 1994 a new management policy of prescribed burning of both the glades and their forest matrix was initiated. Once the forest had been burned, the lizards could disperse kilometers through the forest, thereby reestablishing the processes of dispersal, gene flow, colonization, and local extinction followed by recolonization. This resulted in a dramatic increase in population size and inhabited area. By incorporating a landscape perspective into the management strategy, the eastern collared lizard has been successfully reestablished in a region of historic extirpation.

The Uptake and Distribution of Buried Radionuclides by Pocket Gophers (Thomomys bottae)

2004 ◽  
Vol 39 (3) ◽  
pp. 611-625 ◽  
Author(s):  
R. L. Budd ◽  
G. J. Gonzales ◽  
P. R. Fresquez ◽  
E. A. Lopez
Keyword(s):  
Pocket Gophers ◽  
Thomomys Bottae

Geographic variability and wing plasticity in Sitona sulcifrons (Coleoptera: Curculionidae)

1994 ◽  
Vol 84 (2) ◽  
pp. 269-273
Author(s):  
Tomáš Pavlíček
Keyword(s):  
Gene Flow ◽  
Phenotypic Plasticity ◽  
Genetic Variability ◽  
Relative Size ◽  
The Other ◽  
Wing Size ◽  
Geographic Variability ◽  
Polymorphic Loci ◽  
Local Populations ◽  
Total Variability

AbstractGenetic variability in four polymorphic loci and variation in phenotypic plasticity in relation to the relative size of wings, were compared and contrasted among eight local populations of Sitonasulcifrons Thunberg from the Czech and Slovak republics. The distances between localities from which samples were taken were between 49 and 492 kilometres. The results demonstrated that: 1. The variability between populations was 5.5% and the other 94.5% of the total variability was realized within populations. 2. Significant differences in allozyme frequencies among populations existed when distances were more than 100 km. A similar trend was also found in variability of relative wing size in males among populations when distances were more than 200 km. 3. Overall, a significant deficiency of heterozygotes in relation to Hardy-Weinberg predictions existed from all samples. The results support the idea that, at least inagricultural areas, gene flow in S. sulcifrons does not seem to be strong enough to stabilize one large interbreeding population in distances over 100 kilometres.

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