Skip to Main content Skip to Navigation
Journal articles

When ecological marginality is not geographically peripheral: exploring genetic predictions of the centre-periphery hypothesis in the endemic plant Lilium pomponium

Abstract : Background: Quantifying variation of genetic traits over the geographical range of species is crucial for understanding the factors driving their range dynamics. The center-periphery hypothesis postulates, and many studies support, the idea that genetic diversity decreases and genetic differentiation increases toward the geographical periphery due to population isolation. The effects of environmental marginality on genetic variation has however received much less attention. Methods: We tested the concordance between geographical and environmental gradients and the genetic predictions of center-periphery hypothesis for endemic Lilium pomponium in the southern Alps. Results: We found little evidence for concordance between genetic variation and both geographical and environmental gradients. Although the prediction of increased differentiation at range limits is met, genetic diversity does not decrease towards the geographical periphery. Increased differentiation among peripheral populations, that are not ecologically marginal, may be explained by a decrease in habitat availability that reduces population connectivity. In contrast, a decrease of genetic diversity along environmental but not geographical gradients may be due to the presence of low quality habitats in the different parts of the range of a species that reduce effective population size or increase environmental constraints. As a result, environmental factors may affect population dynamics irrespective of distance from the geographical center of the range. In such situations of discordance between geographical and environmental gradients, the predictions of decreasing genetic diversity and increasing differentiation toward the geographical periphery may not be respected.
Document type :
Journal articles
Complete list of metadata

https://hal-amu.archives-ouvertes.fr/hal-03172039
Contributor : Michelle Leydet <>
Submitted on : Wednesday, March 17, 2021 - 1:52:26 PM
Last modification on : Friday, March 19, 2021 - 3:03:22 AM

File

Casazza et al PeerJ 2021.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

Gabriele Casazza, Carmelo Macrì, Davide Dagnino, Maria Guerrina, Marianick Juin, et al.. When ecological marginality is not geographically peripheral: exploring genetic predictions of the centre-periphery hypothesis in the endemic plant Lilium pomponium. PeerJ, PeerJ, 2021, 9, pp.e11039. ⟨10.7717/peerj.11039⟩. ⟨hal-03172039⟩

Share

Metrics

Record views

87

Files downloads

26