Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Adaptation and Constraint in the Evolution of Specialization of Bahamian Anolis Lizards

Jonathan B. Losos, Duncan J. Irschick and Thomas W. Schoener
Evolution
Vol. 48, No. 6 (Dec., 1994), pp. 1786-1798
DOI: 10.2307/2410508
Stable URL: http://www.jstor.org/stable/2410508
Page Count: 13
  • Read Online (Free)
  • Download ($4.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Adaptation and Constraint in the Evolution of Specialization of Bahamian Anolis Lizards
Preview not available

Abstract

Interspecific interactions affect habitat use and subsequent morphological adaptation in Anolis lizards. We examined populations of two species of Anolis lizards that evolved in the species-rich communities of Cuba and are now widespread in the Bahamas. Because the species occupy islands in the Bahamas that vary in the number of lizard species present and other characteristics, we predicted that directional selection should have led to morphological differentiation. In particular, we expected that populations on one-species islands should have evolved toward a generalist morphology because of the lack of competitors. Divergence in both species has been adaptive; populations that use wider perches have longer legs. Nonetheless, these differences are relatively minor, and none of the populations appears to have differentiated from its ancestral "ecomorph" type toward a more generalized morphology. This stasis mirrors a trend observed in the radiation of Caribbean anoles, which exhibits repeated instances of evolutionary specialization, but few or no cases of reversion to a more generalized condition. The explanation for this directionality of evolution is not obvious but probably involves the tendency of specialized species to continue using and further adapting the niches for which they are specialized even as conditions change.

Page Thumbnails

  • Thumbnail: Page 
1786
    1786
  • Thumbnail: Page 
1787
    1787
  • Thumbnail: Page 
1788
    1788
  • Thumbnail: Page 
1789
    1789
  • Thumbnail: Page 
1790
    1790
  • Thumbnail: Page 
1791
    1791
  • Thumbnail: Page 
1792
    1792
  • Thumbnail: Page 
1793
    1793
  • Thumbnail: Page 
1794
    1794
  • Thumbnail: Page 
1795
    1795
  • Thumbnail: Page 
1796
    1796
  • Thumbnail: Page 
1797
    1797
  • Thumbnail: Page 
1798
    1798