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.

New Measurements of Distribution of Homoplasy and Reliability of Parsimonious Cladograms

Tao Sang
Taxon
Vol. 44, No. 1 (Feb., 1995), pp. 77-82
DOI: 10.2307/1222680
Stable URL: http://www.jstor.org/stable/1222680
Page Count: 6
  • Read Online (Free)
  • Download ($14.00)
  • 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.
New Measurements of Distribution of Homoplasy and Reliability of Parsimonious Cladograms
Preview not available

Abstract

Levels of homoplasy, measured by consistency index (CI) or retention index (RI), have been commonly used as indicators of reliability of parsimonious cladograms. Less attention has been paid to distribution of homoplasy which, however, may be another important parameter for estimating the reliability of cladograms. Average unit character consistency (AUCC), measuring distribution of homoplasy among the characters on parsimonious cladograms, is defined as the average of total unit character consistencies. When cladograms with the same CI are compared, the one with the largest AUCC also has the most asymmetric distribution of homoplasy, i.e., it is compatible with the largest portion of the characters, and homoplasy is concentrated in the smallest portion of cladistically unreliable or fast evolved characters of this cladogram. Homoplasy distribution index (HDI) is defined as the difference between the AUCC and CI, and can be used to compare distribution of homoplasy among cladograms with similar levels of homoplasy. A new measurement of the reliability of parsimonious cladograms, homoplasy distribution ratio (HDR), is defined as the ratio of the HDI to the homoplasy index (HI).

Page Thumbnails

  • Thumbnail: Page 
77
    77
  • Thumbnail: Page 
78
    78
  • Thumbnail: Page 
79
    79
  • Thumbnail: Page 
80
    80
  • Thumbnail: Page 
81
    81
  • Thumbnail: Page 
82
    82