Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones
The Quaternary climate oscillations had a major role in shaping the genetic architecture of living species. In the marine realm, the apparent lack of physical barriers to dispersal allows organisms to track optimum physiological conditions by displacing their distribution ranges. The European anchov...
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ftunivalgarve:oai:sapientia.ualg.pt:10400.1/6817 2023-05-15T17:35:57+02:00 Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones Silva, Gonçalo Jorge Franco Castilho, Rita 2014 http://hdl.handle.net/10400.1/6817 eng eng FRH/BD/36600/2007 http://hdl.handle.net/10400.1/6817 101254180 openAccess Biologia Teoria evolutiva Anchova Mundo antigo Seleção natural Filogeografia Biogeografia Migrações Dispersão Colonização doctoralThesis 2014 ftunivalgarve 2022-05-30T08:46:41Z The Quaternary climate oscillations had a major role in shaping the genetic architecture of living species. In the marine realm, the apparent lack of physical barriers to dispersal allows organisms to track optimum physiological conditions by displacing their distribution ranges. The European anchovy Engraulis encrasicolus is a small pelagic fish that has a broad distribution range in the Atlantic Ocean. Despite the high ability for dispersal, this species exhibit an unusual population structure and two mitochondrial clades clinally distributed along the eastern Atlantic and the Mediterranean. In the present thesis, we investigated North Atlantic anchovy’s response to climate cycles at the leading edges of the distribution range. These small pelagic fishes massively followed suitable thermal conditions cyclically over the Pleistocene and therefore were able to preserve high levels of genetic diversity. We further explored the variation of the mitochondrial clades of the European anchovy and found that the anti-tropically distributed clade is under positive selection, suggesting that temperature is shaping the contemporary distribution of mtDNA clade frequencies. The Old World Anchovies (OWA) complex, of which the European anchovy is part, has taxa distributed in the Pacific and Atlantic oceans. This complex originated at 3.16 Ma in the Indo-Pacific during the late Pliocene and split in two groups, one that remained in the Pacific Ocean and one that colonized the Atlantic Ocean during the Pleistocene (0.62 Ma). The genetic patterns among the OWA indicate no genetic diferentiation between putative species from the Atlantic Ocean, and low levels of ongoing geneflow between Atlantic and Pacific anchovies. Within the Pacific Ocean, two well supported mitochondrial clades reveal ancient trans- Equatorial migrations, while nuclear loci support contemporary admixture. As oscilações climáticas do Quaternário tiveram um papel fundamental na modelação da arquitectura genética das espécies vivas. No meio marinho a ... Doctoral or Postdoctoral Thesis North Atlantic Universidade do Algarve: Sapienta Pacific |
institution |
Open Polar |
collection |
Universidade do Algarve: Sapienta |
op_collection_id |
ftunivalgarve |
language |
English |
topic |
Biologia Teoria evolutiva Anchova Mundo antigo Seleção natural Filogeografia Biogeografia Migrações Dispersão Colonização |
spellingShingle |
Biologia Teoria evolutiva Anchova Mundo antigo Seleção natural Filogeografia Biogeografia Migrações Dispersão Colonização Silva, Gonçalo Jorge Franco Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
topic_facet |
Biologia Teoria evolutiva Anchova Mundo antigo Seleção natural Filogeografia Biogeografia Migrações Dispersão Colonização |
description |
The Quaternary climate oscillations had a major role in shaping the genetic architecture of living species. In the marine realm, the apparent lack of physical barriers to dispersal allows organisms to track optimum physiological conditions by displacing their distribution ranges. The European anchovy Engraulis encrasicolus is a small pelagic fish that has a broad distribution range in the Atlantic Ocean. Despite the high ability for dispersal, this species exhibit an unusual population structure and two mitochondrial clades clinally distributed along the eastern Atlantic and the Mediterranean. In the present thesis, we investigated North Atlantic anchovy’s response to climate cycles at the leading edges of the distribution range. These small pelagic fishes massively followed suitable thermal conditions cyclically over the Pleistocene and therefore were able to preserve high levels of genetic diversity. We further explored the variation of the mitochondrial clades of the European anchovy and found that the anti-tropically distributed clade is under positive selection, suggesting that temperature is shaping the contemporary distribution of mtDNA clade frequencies. The Old World Anchovies (OWA) complex, of which the European anchovy is part, has taxa distributed in the Pacific and Atlantic oceans. This complex originated at 3.16 Ma in the Indo-Pacific during the late Pliocene and split in two groups, one that remained in the Pacific Ocean and one that colonized the Atlantic Ocean during the Pleistocene (0.62 Ma). The genetic patterns among the OWA indicate no genetic diferentiation between putative species from the Atlantic Ocean, and low levels of ongoing geneflow between Atlantic and Pacific anchovies. Within the Pacific Ocean, two well supported mitochondrial clades reveal ancient trans- Equatorial migrations, while nuclear loci support contemporary admixture. As oscilações climáticas do Quaternário tiveram um papel fundamental na modelação da arquitectura genética das espécies vivas. No meio marinho a ... |
author2 |
Castilho, Rita |
format |
Doctoral or Postdoctoral Thesis |
author |
Silva, Gonçalo Jorge Franco |
author_facet |
Silva, Gonçalo Jorge Franco |
author_sort |
Silva, Gonçalo Jorge Franco |
title |
Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
title_short |
Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
title_full |
Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
title_fullStr |
Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
title_full_unstemmed |
Study of genetic gradients among populations of Atlantic anchovy (Engraulis encrasicolus L.) located along marine ecotones |
title_sort |
study of genetic gradients among populations of atlantic anchovy (engraulis encrasicolus l.) located along marine ecotones |
publishDate |
2014 |
url |
http://hdl.handle.net/10400.1/6817 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
FRH/BD/36600/2007 http://hdl.handle.net/10400.1/6817 101254180 |
op_rights |
openAccess |
_version_ |
1766135267677175808 |