Vista normal Vista MARC Vista ISBD

Naturally rare versus newly rare: demographic inferences on two timescales inform conservation of Galápagos giant tortoises.

Por:

Garrick, Ryan C

Colaborador(es):

Tipo de material:

ArtículoIdioma: Inglés Tema(s):

Clasificación CDD:

22 597.9246

Recursos en línea:

Haga clic para acceso en línea

En: Ecology and Evolution Vol. 5, no. 3 (December 2014), p. 676-694Tema: Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (Ne) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galapagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ~100 generations, ~2500 years) and deep (pre-Holocene, >10 thousandyears ago) timescales. At the deep timescale, three populations showed strong signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical Ne of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary Ne were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, Ne generally represented ~0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this distinction should facilitate prioritization of management action.

Etiquetas de esta biblioteca: No hay etiquetas de esta biblioteca para este título.

Existencias ( 2 )
Notas de título ( 2 )

Existencias
Imagen de cubierta	Tipo de ítem	Biblioteca actual	Biblioteca de origen	Colección	Ubicación en estantería	Signatura topográfica	Materiales especificados	Info Vol	URL	Copia número	Estado	Notas	Fecha de vencimiento	Código de barras	Reserva de ítems	Prioridad de la cola de reserva de ejemplar	Reservas para cursos
	Artículo	Corley Smith Library Artículos		Galápagos		597.9246 GAR (Navegar estantería(Abre debajo))					Disponible			2017-2131
	Documento electrónico	Corley Smith Library Colección PDF		Galápagos		597.9246 GAR 2014 (Navegar estantería(Abre debajo))					Disponible			2021-1829

Navegando Corley Smith Library estanterías,Ubicación en estantería: Colección PDF,Colección: Galápagos Cerrar el navegador de estanterías (Oculta el navegador de estanterías)

Previo								Siguiente
Previo	597.924 TAP 2015 Giant tortoises hatch on Galapagos island /	597.924 TOW 1925 The Galapagos tortoises in their relation to the whaling industry :	597.9246 FRO 2014 The ecological consequences of megafaunal loss:	597.9246 GAR 2014 Naturally rare versus newly rare:	597.9246 GIB 2014 Demographic Outcomes and Ecosystem Implications of Giant Tortoise Reintroduction to Española Island, Galapagos.	597.9246 LOI 2013 Population genomics of the endangered giant Galápagos tortoise.	597.9246 MAR 2013 Hasta siempre solitario Jorge.	Siguiente

Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (Ne) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galapagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ~100 generations, ~2500 years) and deep (pre-Holocene, >10 thousandyears ago) timescales. At the deep timescale, three populations showed strong
signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical Ne of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary Ne were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, Ne generally represented ~0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this
distinction should facilitate prioritization of management action.

English