Selection on a genetic polymorphism counteracts ecological speciation in a stick insect.

Details

Serval ID
serval:BIB_BC8E03390997
Type
Article: article from journal or magazin.
Collection
Publications
Title
Selection on a genetic polymorphism counteracts ecological speciation in a stick insect.
Journal
Current Biology : Cb
Author(s)
Comeault A.A., Flaxman S.M., Riesch R., Curran E., Soria-Carrasco V., Gompert Z., Farkas T.E., Muschick M., Parchman T.L., Schwander T., Slate J., Nosil P.
ISSN
1879-0445 (Electronic)
ISSN-L
0960-9822
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
25
Number
15
Pages
1975-1981
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
The interplay between selection and aspects of the genetic architecture of traits (such as linkage, dominance, and epistasis) can either drive or constrain speciation [1-3]. Despite accumulating evidence that speciation can progress to "intermediate" stages-with populations evolving only partial reproductive isolation-studies describing selective mechanisms that impose constraints on speciation are more rare than those describing drivers. The stick insect Timema cristinae provides an example of a system in which partial reproductive isolation has evolved between populations adapted to different host plant environments, in part due to divergent selection acting on a pattern polymorphism [4, 5]. Here, we demonstrate how selection on a green/melanistic color polymorphism counteracts speciation in this system. Specifically, divergent selection between hosts does not occur on color phenotypes because melanistic T. cristinae are cryptic on the stems of both host species, are resistant to a fungal pathogen, and have a mating advantage. Using genetic crosses and genome-wide association mapping, we quantify the genetic architecture of both the pattern and color polymorphism, illustrating their simple genetic control. We use these empirical results to develop an individual-based model that shows how the melanistic phenotype acts as a "genetic bridge" that increases gene flow between populations living on different hosts. Our results demonstrate how variation in the nature of selection acting on traits, and aspects of trait genetic architecture, can impose constraints on both local adaptation and speciation.
Keywords
Animals, Crosses, Genetic, Female, Genetic Speciation, Genome-Wide Association Study, Insects/genetics, Insects/physiology, Male, Mating Preference, Animal, Pigmentation, Polymorphism, Genetic, Reproductive Isolation, Selection, Genetic
Pubmed
Web of science
Open Access
Yes
Create date
28/05/2015 10:17
Last modification date
09/05/2019 0:30
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