Phenotypic divergence during the invasion of Phyla canescens in Australia and France: evidence for selection-driven evolution.
Rapid adaptive evolution has been advocated as a mechanism that promotes invasion. Demonstrating adaptive evolution in invasive species requires rigorous analysis of phenotypic shifts driven by selection. Here, we document selection-driven evolution of Phyla canescens, an Argentine weed, in two invaded regions (Australia and France). Invasive populations possessed similar or higher diversity than native populations, and displayed mixed lineages from different sources, suggesting that genetic bottlenecks in both countries might have been alleviated by multiple introductions. Compared to native populations, Australian populations displayed more investment in sexual reproduction, whereas French populations possessed enhanced vegetative reproduction and growth. We partitioned evolutionary forces (selection vs. stochastic events) using two independent methods. Results of both analyses suggest that the pattern of molecular and phenotypic variability among regions was consistent with selection-driven evolution, rather than stochastic events. Our findings indicate that selection has shaped the evolution of P. canescens in two different invaded regions.
CSIRO Entomology, 120 Meiers Road, Indooroopilly, QLD 4068, Australia.
Cheng-Yuan
CY
Xu
Mic H
MH
Julien
Mohammad
M
Fatemi
Christophe
C
Girod
Rieks D
RD
Van Klinken
Caroline L
CL
Gross
Stephen J
SJ
Novak
D000222:Adaptation, Physiological; D001315:Australia; D005075:Biological Evolution; D005602:France; D014644:Genetic Variation; D010641:Phenotype; D010802:Phylogeny; D011157:Population Dynamics; D012098:Reproduction; D012641:Selection, Genetic; D029648:Verbenaceae / Q000145:classification / Q000235:genetics / Q000502:physiology*