Evidence for adaptive radiation from a phylogenetic study of plant defenses.

Détails

ID Serval
serval:BIB_F3E4819E679B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Evidence for adaptive radiation from a phylogenetic study of plant defenses.
Périodique
Proceedings of the National Academy of Sciences of the United States of America
Auteur(s)
Agrawal A.A., Fishbein M., Halitschke R., Hastings A.P., Rabosky D.L., Rasmann S.
ISSN
1091-6490 (Electronic)
ISSN-L
0027-8424
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
106
Numéro
43
Pages
18067-18072
Langue
anglais
Résumé
One signature of adaptive radiation is a high level of trait change early during the diversification process and a plateau toward the end of the radiation. Although the study of the tempo of evolution has historically been the domain of paleontologists, recently developed phylogenetic tools allow for the rigorous examination of trait evolution in a tremendous diversity of organisms. Enemy-driven adaptive radiation was a key prediction of Ehrlich and Raven's coevolutionary hypothesis [Ehrlich PR, Raven PH (1964) Evolution 18:586-608], yet has remained largely untested. Here we examine patterns of trait evolution in 51 North American milkweed species (Asclepias), using maximum likelihood methods. We study 7 traits of the milkweeds, ranging from seed size and foliar physiological traits to defense traits (cardenolides, latex, and trichomes) previously shown to impact herbivores, including the monarch butterfly. We compare the fit of simple random-walk models of trait evolution to models that incorporate stabilizing selection (Ornstein-Ulenbeck process), as well as time-varying rates of trait evolution. Early bursts of trait evolution were implicated for 2 traits, while stabilizing selection was implicated for several others. We further modeled the relationship between trait change and species diversification while allowing rates of trait evolution to vary during the radiation. Species-rich lineages underwent a proportionately greater decline in latex and cardenolides relative to species-poor lineages, and the rate of trait change was most rapid early in the radiation. An interpretation of this result is that reduced investment in defensive traits accelerated diversification, and disproportionately so, early in the adaptive radiation of milkweeds.
Mots-clé
Asclepias/genetics, Genetic Speciation, Multifactorial Inheritance, Phylogeny, Selection, Genetic
Pubmed
Web of science
Open Access
Oui
Création de la notice
03/10/2011 14:39
Dernière modification de la notice
20/08/2019 17:20
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