Strong reinforcing selection in a Texas wildflower.

Journal Article (Journal Article)

Reinforcement, the process of increased reproductive isolation due to selection against hybrids, is an important mechanism by which natural selection contributes to speciation [1]. Empirical studies suggest that reinforcement has generated reproductive isolation in many taxa (reviewed in [2-4]), and theoretical work shows it can act under broad selective conditions [5-11]. However, the strength of selection driving reinforcement has never been measured in nature. Here, we quantify the strength of reinforcing selection in the Texas wildflower Phlox drummondii using a strategy that weds a population genetic model with field data. Reinforcement in this system is caused by variation in two loci that affect flower color [12]. We quantify sharp clines in flower color where this species comes into contact with its congener, Phlox cuspidata. We develop a spatially explicit population genetic model for these clines based on the known genetics of flower color. We fit our model to the data using likelihood, and we searched parameter space using Markov chain Monte Carlo methods. We find that selection on flower color genes generated by reinforcement is exceptionally strong. Our findings demonstrate that natural selection can play a decisive role in the evolution of reproductive isolation through the process of reinforcement.

Full Text

Duke Authors

Cited Authors

  • Hopkins, R; Guerrero, RF; Rausher, MD; Kirkpatrick, M

Published Date

  • September 2014

Published In

Volume / Issue

  • 24 / 17

Start / End Page

  • 1995 - 1999

PubMed ID

  • 25155503

Electronic International Standard Serial Number (EISSN)

  • 1879-0445

International Standard Serial Number (ISSN)

  • 0960-9822

Digital Object Identifier (DOI)

  • 10.1016/j.cub.2014.07.027


  • eng