Causes and consequences of fine-scale population structure in a critically endangered freshwater seal.
BMC Ecol
; 14: 22, 2014 Jul 09.
Article
em En
| MEDLINE
| ID: mdl-25005257
ABSTRACT
BACKGROUND:
Small, genetically uniform populations may face an elevated risk of extinction due to reduced environmental adaptability and individual fitness. Fragmentation can intensify these genetic adversities and, therefore, dispersal and gene flow among subpopulations within an isolated population is often essential for maintaining its viability. Using microsatellite and mtDNA data, we examined genetic diversity, spatial differentiation, interregional gene flow, and effective population sizes in the critically endangered Saimaa ringed seal (Phoca hispida saimensis), which is endemic to the large but highly fragmented Lake Saimaa in southeastern Finland.RESULTS:
Microsatellite diversity within the subspecies (HE = 0.36) ranks among the lowest thus far recorded within the order Pinnipedia, with signs of ongoing loss of individual heterozygosity, reflecting very low effective subpopulation sizes. Bayesian assignment analyses of the microsatellite data revealed clear genetic differentiation among the main breeding areas, but interregional structuring was substantially weaker in biparentally inherited microsatellites (FST = 0.107) than in maternally inherited mtDNA (FST = 0.444), indicating a sevenfold difference in the gene flow mediated by males versus females.CONCLUSIONS:
Genetic structuring in the population appears to arise from the joint effects of multiple factors, including small effective subpopulation sizes, a fragmented lacustrine habitat, and behavioural dispersal limitation. The fine-scale differentiation found in the landlocked Saimaa ringed seal is especially surprising when contrasted with marine ringed seals, which often exhibit near-panmixia among subpopulations separated by hundreds or even thousands of kilometres. Our results demonstrate that population structures of endangered animals cannot be predicted based on data on even closely related species or subspecies.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Variação Genética
/
Espécies em Perigo de Extinção
/
Focas Verdadeiras
/
Genética Populacional
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
Limite:
Animals
País/Região como assunto:
Europa
Idioma:
En
Revista:
BMC Ecol
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Finlândia