Abrupt deceleration of molecular evolution linked to the origin of arborescence in ferns.

Journal Article

Molecular rate heterogeneity, whereby rates of molecular evolution vary among groups of organisms, is a well-documented phenomenon. Nonetheless, its causes are poorly understood. For animals, generation time is frequently cited because longer-lived species tend to have slower rates of molecular evolution than their shorter-lived counterparts. Although a similar pattern has been uncovered in flowering plants, using proxies such as growth form, the underlying process has remained elusive. Here, we find a deceleration of molecular evolutionary rate to be coupled with the origin of arborescence in ferns. Phylogenetic branch lengths within the “tree fern” clade are considerably shorter than those of closely related lineages, and our analyses demonstrate that this is due to a significant difference in molecular evolutionary rate. Reconstructions reveal that an abrupt rate deceleration coincided with the evolution of the long-lived tree-like habit at the base of the tree fern clade. This suggests that a generation time effect may well be ubiquitous across the green tree of life, and that the search for a responsible mechanism must focus on characteristics shared by all vascular plants. Discriminating among the possibilities will require contributions from various biological disciplines,but will be necessary for a full appreciation of molecular evolution.

Full Text

Duke Authors

Cited Authors

  • Korall, P; Schuettpelz, E; Pryer, KM

Published Date

  • September 2010

Published In

Volume / Issue

  • 64 / 9

Start / End Page

  • 2786 - 2792

PubMed ID

  • 20394660

Electronic International Standard Serial Number (EISSN)

  • 1558-5646

Digital Object Identifier (DOI)

  • 10.1111/j.1558-5646.2010.01000.x

Language

  • eng

Conference Location

  • United States