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Museum DNA reveals the demographic history of the endangered Seychelles warbler.

Spurgin LG, Wright DJ, van der Velde M, Collar NJ, Komdeur J, Burke T, Richardson DS - Evol Appl (2014)

Bottom Line: We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure.Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices.Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of East Anglia Norwich, Norfolk, UK ; Behavioural Ecology and Self-organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen Groningen, The Netherlands.

ABSTRACT
The importance of evolutionary conservation - how understanding evolutionary forces can help guide conservation decisions - is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) - an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral N e of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation.

No MeSH data available.


Related in: MedlinePlus

Expected heterozygosity (black dots and solid bars) and allelic richness (grey dots and dashed bars) averaged over 12 microsatellite loci in museum (M) and contemporary Seychelles warbler populations. Error bars represent standard error.
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fig02: Expected heterozygosity (black dots and solid bars) and allelic richness (grey dots and dashed bars) averaged over 12 microsatellite loci in museum (M) and contemporary Seychelles warbler populations. Error bars represent standard error.

Mentions: Pairwise FST estimates between museum and contemporary samples were moderately large and highly significant (all FST > 0.1, P < 0.001; Table2), but there was no significant differentiation between the 1997 and 2011 populations (FST = 0.001, P = 0.2; Table2). A PCA suggested that the Cousin and Marianne museum samples formed two separate clusters, with the contemporary samples forming a separate third cluster (Fig.2). STRUCTURE analyses indicated three and two genetic clusters using the log likelihood and ΔK methods, respectively, which corresponded closely to the results from the PCA (Figure S1). The only difference between the PCA and STRUCTURE analyses was that STRUCTURE, when K = 2, grouped the Marianne samples with the Cousin museum samples (Figure S1) – however, this is most likely the result of the low sample size on Marianne (Kalinowski 2011).


Museum DNA reveals the demographic history of the endangered Seychelles warbler.

Spurgin LG, Wright DJ, van der Velde M, Collar NJ, Komdeur J, Burke T, Richardson DS - Evol Appl (2014)

Expected heterozygosity (black dots and solid bars) and allelic richness (grey dots and dashed bars) averaged over 12 microsatellite loci in museum (M) and contemporary Seychelles warbler populations. Error bars represent standard error.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231601&req=5

fig02: Expected heterozygosity (black dots and solid bars) and allelic richness (grey dots and dashed bars) averaged over 12 microsatellite loci in museum (M) and contemporary Seychelles warbler populations. Error bars represent standard error.
Mentions: Pairwise FST estimates between museum and contemporary samples were moderately large and highly significant (all FST > 0.1, P < 0.001; Table2), but there was no significant differentiation between the 1997 and 2011 populations (FST = 0.001, P = 0.2; Table2). A PCA suggested that the Cousin and Marianne museum samples formed two separate clusters, with the contemporary samples forming a separate third cluster (Fig.2). STRUCTURE analyses indicated three and two genetic clusters using the log likelihood and ΔK methods, respectively, which corresponded closely to the results from the PCA (Figure S1). The only difference between the PCA and STRUCTURE analyses was that STRUCTURE, when K = 2, grouped the Marianne samples with the Cousin museum samples (Figure S1) – however, this is most likely the result of the low sample size on Marianne (Kalinowski 2011).

Bottom Line: We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure.Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices.Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of East Anglia Norwich, Norfolk, UK ; Behavioural Ecology and Self-organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen Groningen, The Netherlands.

ABSTRACT
The importance of evolutionary conservation - how understanding evolutionary forces can help guide conservation decisions - is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) - an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral N e of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation.

No MeSH data available.


Related in: MedlinePlus