{"id":{"repo_id":"hull","oai_identifier":"oai:hull-repository.worktribe.com:4212242"},"canonical_url":"https://search.dev.ndltd.org/etd/hull/oai:hull-repository.worktribe.com:4212242","repository":{"repo_id":"hull","name":"University of Hull","base_url":"https://hull-repository.worktribe.com/oaiprovider"},"display":{"title":"Genetic structure and colonisation history of European and UK population of Gammarus pulex","abstract":"The structure of populations has been studied for many years and there have been three main factors that have been suggested as the cause for present-day distributions of species, those being environment, biology and history. With the use of molecular data and advanced phylogeographic approaches it is now possible to distinguish between the main causes of population structuring. The present study considers the extent of population structure in G. pulex on regional (UK) and large geographic (Europe) scales using studies of molecular genetic (allozymes, mtDNA sequencing and microsatellites) and morphological variation.Molecular analysis of Gammarus pulex in Europe revealed more diversity than previously thought. This was thought to be a consequence of two separate waves of colonisation after the formation of the major drainages in the Miocene. The UK appears to have been colonised once from either the Elbe, Mosel and Rhine drainages separately or cumulatively across the drainage basins late in the Pleistocene before a land bridge connection to mainland Europe was submerged. Limited molecular variation in the UK is thought to be a result of reduced genetic variation in the colonising individuals. This in turn was caused by repeated founder events during population expansion and contraction from European refugia.A detailed analysis of a transplantation experiment in 1950 in the Isle of Man revealed little genetic impoverishment of the introduced population when compared to the source. In contrast, morphological variation increased in the introduced population. Unlike in mainland Europe there was no historical explanation for the diversity recorded (as the introduced population was so young) and, in the absence of fragmentation, speciation and colonisation the contemporary forces of gene flow, selection and limited genetic drift are thought to be the determining factors in population structure.","abstract_html":"The structure of populations has been studied for many years and there have been three main factors that have been suggested as the cause for present-day distributions of species, those being environment, biology and history. With the use of molecular data and advanced phylogeographic approaches it is now possible to distinguish between the main causes of population structuring. The present study considers the extent of population structure in G. pulex on regional (UK) and large geographic (Europe) scales using studies of molecular genetic (allozymes, mtDNA sequencing and microsatellites) and morphological variation.Molecular analysis of Gammarus pulex in Europe revealed more diversity than previously thought. This was thought to be a consequence of two separate waves of colonisation after the formation of the major drainages in the Miocene. The UK appears to have been colonised once from either the Elbe, Mosel and Rhine drainages separately or cumulatively across the drainage basins late in the Pleistocene before a land bridge connection to mainland Europe was submerged. Limited molecular variation in the UK is thought to be a result of reduced genetic variation in the colonising individuals. This in turn was caused by repeated founder events during population expansion and contraction from European refugia.A detailed analysis of a transplantation experiment in 1950 in the Isle of Man revealed little genetic impoverishment of the introduced population when compared to the source. In contrast, morphological variation increased in the introduced population. Unlike in mainland Europe there was no historical explanation for the diversity recorded (as the introduced population was so young) and, in the absence of fragmentation, speciation and colonisation the contemporary forces of gene flow, selection and limited genetic drift are thought to be the determining factors in population structure.","abstract_has_math":false,"creators":["Hadfield, Simon John"],"institution":"University of Hull","degree_name":"PhD","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Carvalho, Gary R."],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-24T02:33:28Z","subjects":["Biological sciences"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:hull-repository.worktribe.com:4212242"],"render_values":[{"text":"oai:hull-repository.worktribe.com:4212242","href":null,"code":true}]}]},"links":{"outbound_url":"https://hull-repository.worktribe.com/4212242/1/Thesis","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Carvalho, Gary R."]},{"key":"dc:creator","label":"Author","values":["Hadfield, Simon John"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2002-09-01"]},{"key":"dc:date.issued","label":"Date","values":["2002"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Hull"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://hull-repository.worktribe.com/output/4212242"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biological sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:hull-repository.worktribe.com:4212242"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hull-repository.worktribe.com/4212242/1/Thesis"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The structure of populations has been studied for many years and there have been three main factors that have been suggested as the cause for present-day distributions of species, those being environment, biology and history. With the use of molecular data and advanced phylogeographic approaches it is now possible to distinguish between the main causes of population structuring. The present study considers the extent of population structure in G. pulex on regional (UK) and large geographic (Europe) scales using studies of molecular genetic (allozymes, mtDNA sequencing and microsatellites) and morphological variation.Molecular analysis of Gammarus pulex in Europe revealed more diversity than previously thought. This was thought to be a consequence of two separate waves of colonisation after the formation of the major drainages in the Miocene. The UK appears to have been colonised once from either the Elbe, Mosel and Rhine drainages separately or cumulatively across the drainage basins late in the Pleistocene before a land bridge connection to mainland Europe was submerged. Limited molecular variation in the UK is thought to be a result of reduced genetic variation in the colonising individuals. This in turn was caused by repeated founder events during population expansion and contraction from European refugia.A detailed analysis of a transplantation experiment in 1950 in the Isle of Man revealed little genetic impoverishment of the introduced population when compared to the source. In contrast, morphological variation increased in the introduced population. Unlike in mainland Europe there was no historical explanation for the diversity recorded (as the introduced population was so young) and, in the absence of fragmentation, speciation and colonisation the contemporary forces of gene flow, selection and limited genetic drift are thought to be the determining factors in population structure."]},{"key":"dc:title","label":"Title","values":["Genetic structure and colonisation history of European and UK population of Gammarus pulex"]}]}],"canonical_facts":{"dc:contributor.advisor":["Carvalho, Gary R."],"dc:creator":["Hadfield, Simon John"],"dc:date":["2002-09-01"],"dc:date.issued":["2002"],"dc:description.abstract":["The structure of populations has been studied for many years and there have been three main factors that have been suggested as the cause for present-day distributions of species, those being environment, biology and history. With the use of molecular data and advanced phylogeographic approaches it is now possible to distinguish between the main causes of population structuring. The present study considers the extent of population structure in G. pulex on regional (UK) and large geographic (Europe) scales using studies of molecular genetic (allozymes, mtDNA sequencing and microsatellites) and morphological variation.Molecular analysis of Gammarus pulex in Europe revealed more diversity than previously thought. This was thought to be a consequence of two separate waves of colonisation after the formation of the major drainages in the Miocene. The UK appears to have been colonised once from either the Elbe, Mosel and Rhine drainages separately or cumulatively across the drainage basins late in the Pleistocene before a land bridge connection to mainland Europe was submerged. Limited molecular variation in the UK is thought to be a result of reduced genetic variation in the colonising individuals. This in turn was caused by repeated founder events during population expansion and contraction from European refugia.A detailed analysis of a transplantation experiment in 1950 in the Isle of Man revealed little genetic impoverishment of the introduced population when compared to the source. In contrast, morphological variation increased in the introduced population. Unlike in mainland Europe there was no historical explanation for the diversity recorded (as the introduced population was so young) and, in the absence of fragmentation, speciation and colonisation the contemporary forces of gene flow, selection and limited genetic drift are thought to be the determining factors in population structure."],"dc:identifier":["oai:hull-repository.worktribe.com:4212242"],"dc:identifier.uri":["https://hull-repository.worktribe.com/4212242/1/Thesis"],"dc:language":["en"],"dc:publisher.institution":["University of Hull"],"dc:relation.isreferencedby":["https://hull-repository.worktribe.com/output/4212242"],"dc:subject":["Biological sciences"],"dc:title":["Genetic structure and colonisation history of European and UK population of Gammarus pulex"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["PhD"]},"updated_at":"2026-07-24T02:33:28Z"}