Differences in (G+C) content between species: a commentary on Forsdyke's "chromosomal viewpoint" of speciation.

Journal Article (Journal Article)

Forsdyke (1999) has recently argued that differences in (G+C)%, or G+C content, may trigger new species formation. He further argues that the genic model has shortcomings that can be overcome by his "chromosomal" (hereafter, "G+C") model. We disagree on several counts. First, we do not accept that the genic model has the shortcomings suggested by Forsdyke. There is an abundance of empirical support for the contribution of individual genes, as well as of mapped chromosomal regions, to post-zygotic reproductive isolation (and Haldane's rule). Further, we argue that the G+C model suffers from the same theoretical difficulties as other speciation models based on underdominance. We also question the evidence Forsdyke uses to support his model. Finally, we describe analyses of G+C content in a well-studied model system of speciation (the Drosophila melanogaster species complex), the results of which are incompatible with the G+C model. Thus, while Forsdyke's G+C model cannot be explicitly ruled out, it is not directly supported by empirical data. In contrast, the genic model is well supported by empirical data, holds up on theoretical grounds, and does not require any assistance from the G+C model.

Full Text

Duke Authors

Cited Authors

  • Kliman, RM; Rogers, BT; Noor, MA

Published Date

  • March 2001

Published In

Volume / Issue

  • 209 / 2

Start / End Page

  • 131 - 140

PubMed ID

  • 11401455

Pubmed Central ID

  • 11401455

Electronic International Standard Serial Number (EISSN)

  • 1095-8541

International Standard Serial Number (ISSN)

  • 0022-5193

Digital Object Identifier (DOI)

  • 10.1006/jtbi.2000.2242


  • eng