The maintenance of hybrid zones across a disturbance gradient.

Details

Serval ID
serval:BIB_D43289CA7EA6
Type
Article: article from journal or magazin.
Collection
Publications
Title
The maintenance of hybrid zones across a disturbance gradient.
Journal
Heredity
Author(s)
Dorken M.E., Pannell J.R.
ISSN
0018-067X (Print)
ISSN-L
0018-067X
Publication state
Published
Issued date
2007
Peer-reviewed
Oui
Volume
99
Number
1
Pages
89-101
Language
english
Abstract
The parapatric distribution of genetically divergent lineages in hybrid zones can be maintained by ecological differences (dispersal-independent 'ecotonal' hybrid zones), by frequency- and density-dependent interference when they intermingle and mate (dispersal-dependent 'tension' hybrid zones), or by both processes acting together. One potentially important ecological factor that has received little theoretical attention is gradients in habitat disturbance. Such gradients may be particularly important in contact zones in which the interacting lineages differ in their sexual system (e.g., self-fertile versus obligately outcrossing) because self-fertility promotes the colonization of open patches. Here we use a spatially explicit metapopulation model to examine the dynamics of a dispersal-dependent ecotonal hybrid zone across a gradient in the rate of habitat disturbance, where competing lineages differ in their sexual system. We found that self-fertility promoted the maintenance of one lineage over its outcrossing counterpart at high extinction rates, predominantly because self-fertility confers reproductive assurance. Additionally, greater seed and pollen production promoted a lineage's persistence by reducing the seed fertility of its counterpart through hybridization. Our results draw attention to the joint effects of ecological and endogenous selection in regulating the location of hybrid zones. Our study also casts new light on the maintenance of the parapatric distribution of incompatible lineages of Spanish populations of the plant Mercurialis annua. In particular, we expect the rate of movement of a contact zone in eastern Spain to increase as it moves further south, contrary to earlier predictions.
Keywords
Chimera, Environment, Euphorbiaceae/genetics, Hybridization, Genetic, Models, Biological, Pollen/physiology, Reproduction, Seeds/physiology
Pubmed
Web of science
Open Access
Yes
Create date
20/09/2011 7:39
Last modification date
20/08/2019 15:54
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