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Full-Text Articles in Life Sciences

Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell Jan 1998

Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell

Dissertations, Theses, and Masters Projects

I examined variability in the shell form of 25 Littorina obtusata populations from Massachusetts to northern Maine. I chose this scale because the history of one of L. obtusata's principal predators, the crab Carcinus maenas, has changed dramatically in the past 100 years. Before 1900, Carcinus did not occur north of Cape Cod, Massachusetts, but by 1950 it had reached Canadian border. Moreover, in summer water temperatures during average 6-8&\sp\circ&C colder at northern locations. Shell thickness and mass increased and body mass decreased with increasing latitude. to test whether these patterns reflect plasticity in response to predators, snails from two …


Systematic And Population Genetic Analyses Of Northern Vs Southern Yellow Lady's Slippers (Cypripedium Parviflorum Vars Parviflorum, Pubescens, And Makasin): Inference From Isozyme And Morphological Data, Lisa Ellen Wallace Jan 1997

Systematic And Population Genetic Analyses Of Northern Vs Southern Yellow Lady's Slippers (Cypripedium Parviflorum Vars Parviflorum, Pubescens, And Makasin): Inference From Isozyme And Morphological Data, Lisa Ellen Wallace

Dissertations, Theses, and Masters Projects

No abstract provided.


Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill Jan 1995

Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill

Dissertations, Theses, and Masters Projects

No abstract provided.


Determination Of The Natal Origin And Genetic Stock Composition Of A Juvenile Feeding Population Of The Loggerhead Turtle (Caretta Caretta) In Chesapeake Bay, Jeffrey Worner Norrgard Jan 1995

Determination Of The Natal Origin And Genetic Stock Composition Of A Juvenile Feeding Population Of The Loggerhead Turtle (Caretta Caretta) In Chesapeake Bay, Jeffrey Worner Norrgard

Dissertations, Theses, and Masters Projects

No abstract provided.


A Correlated Lm/Sem Method For The Morphological Characterization Of Gene Expression In Xenopus Laevis, Laura Rochmis Jan 1995

A Correlated Lm/Sem Method For The Morphological Characterization Of Gene Expression In Xenopus Laevis, Laura Rochmis

Dissertations, Theses, and Masters Projects

No abstract provided.


Global Phylogeography Of Yellowfin Tuna, Thunnus Albacares, And Mackerels Of The Genus Scomber, Daniel R. Scoles Jan 1994

Global Phylogeography Of Yellowfin Tuna, Thunnus Albacares, And Mackerels Of The Genus Scomber, Daniel R. Scoles

Dissertations, Theses, and Masters Projects

Intraspecific genetic relationships within yellowfin tuna, Thunnus albacares, and three mackerels of the genus Scomber were studied by restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA). The comparison of these scombrids, with different larval distributions, adult distributions, and vagilities, served to investigate the hypothesis that population structure in marine fishes results from geographic and physical oceanographic processes that limit dispersal of early life history stages. Samples of 20 yellowfin tuna were examined from each of five Pacific locations and one Atlantic location. MtDNA analysis with 12 informative restriction endonucleases demonstrated considerable genetic variation, as evidenced by overall nucleon …


Population Genetics Of Selected Species Of Sharks, Edward J. Heist Jan 1994

Population Genetics Of Selected Species Of Sharks, Edward J. Heist

Dissertations, Theses, and Masters Projects

Molecular genetic techniques were used to elucidate genetic population structure in three species of sharks, the coastal sandbar shark (Carcharhinus plumbeus) and Atlantic sharpnose shark (Rhizoprionodon terraenovae), and the pelagic shortfin mako (Isurus oxyrinchus). Allozyme analysis and analysis of restriction fragment length polymorphisms (RFLP) of mitochondrial DNA (mtDNA) were used to test the null hypothesis that the mid-Atlantic Bight and the Gulf of Mexico sandbar sharks consist of a single gene pool. RFLP analysis of mtDNA was used to determine the pattern and level of genetic divergence in the sandbar shark between the western North Atlantic and the Eastern Indian …


Generic Identification And Patterns Of External Pigment In Larval Gobies (Pisces: Gobiidae) From The Belize Barrier Reef, Elizabeth D. Maddox Jan 1992

Generic Identification And Patterns Of External Pigment In Larval Gobies (Pisces: Gobiidae) From The Belize Barrier Reef, Elizabeth D. Maddox

Dissertations, Theses, and Masters Projects

No abstract provided.


Comparative Ecology, Morphology, And Population Genetics Of Black Triggerfish, Melichthys Niger, Kathryn D. Kavanagh Jan 1991

Comparative Ecology, Morphology, And Population Genetics Of Black Triggerfish, Melichthys Niger, Kathryn D. Kavanagh

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effect Of Tissue Culture Medium Composition On Fragile X Expression, Jennifer Anne Hyman Jan 1989

The Effect Of Tissue Culture Medium Composition On Fragile X Expression, Jennifer Anne Hyman

Dissertations, Theses, and Masters Projects

No abstract provided.


The Frequency Of The Fragile-X Chromosome In Twenty-Three Autistics From Eastern Virginia, Jennifer Morris Ferguson Jan 1984

The Frequency Of The Fragile-X Chromosome In Twenty-Three Autistics From Eastern Virginia, Jennifer Morris Ferguson

Dissertations, Theses, and Masters Projects

No abstract provided.