A test of the size-constraint hypothesis for a limit to sexual dimorphism in plants.

Details

Serval ID
serval:BIB_29C580E60044
Type
Article: article from journal or magazin.
Collection
Publications
Title
A test of the size-constraint hypothesis for a limit to sexual dimorphism in plants.
Journal
Oecologia
Author(s)
Labouche A.M., Pannell J.R.
ISSN
1432-1939 (Electronic)
ISSN-L
0029-8549
Publication state
Published
Issued date
07/2016
Peer-reviewed
Oui
Volume
181
Number
3
Pages
873-884
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
In flowering plants, many dioecious species display a certain degree of sexual dimorphism in non-reproductive traits, but this dimorphism tends to be much less striking than that found in animals. Sexual size dimorphism in plants may be limited because competition for light in crowded environments so strongly penalises small plants. The idea that competition for light constrains the evolution of strong sexual size dimorphism in plants (the size-constraint hypothesis) implies a strong dependency of the expression of sexual size dimorphism on the neighbouring density as a result of the capacity of plants to adjust their reproductive effort and investment in growth in response to their local environment. Here, we tested this hypothesis by experimentally altering the context of competition for light among male-female pairs of the light-demanding dioecious annual plant Mercurialis annua. We found that males were smaller than females across all treatments, but sexual size dimorphism was diminished for pairs grown at higher densities. This result is consistent with the size-constraint hypothesis. We discuss our results in terms of the tension between selection on size acting in opposite directions on males and females, which have different optima under sexual selection, and stabilizing selection for similar sizes in males and females, which have similar optima under viability selection for plasticity in size expression under different density conditions.

Keywords
Angiosperms, Animals, Biological Evolution, Euphorbiaceae, Reproduction, Sex Characteristics
Pubmed
Create date
14/04/2016 17:39
Last modification date
20/08/2019 14:09
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