Evaluating Phylogenetic Tree Shape: Two Modifications to Fusco & Cronk's Method
✍ Scribed by ANDY PURVIS; ARIS KATZOURAKIS; PAUL-MICHAEL AGAPOW
- Book ID
- 102613529
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 196 KB
- Volume
- 214
- Category
- Article
- ISSN
- 0022-5193
No coin nor oath required. For personal study only.
✦ Synopsis
Measurement of the degree of asymmetry in phylogenetic trees is important because a tree's shape re#ects the process by which it has grown. For example, highly asymmetric trees are evidence that species have had di!erent potential for diversi"cation. Of the tree shape measures in the literature, that proposed by Fusco & Cronk (J. theor. Biol. 175, 235}243) appears to be particularly useful, because it does not require fully-resolved trees whose terminals are of equal taxonomic rank. The value of the asymmetry or imbalance at a node is intended to be independent of the number of species ultimately descended from the node. In this paper, however, we point out that the value does depend upon species number. We propose two modi"cations that remove the dependency and so increase the measure's usefulness. We illustrate the use of the modi"ed measures, which are implemented in a freelyavailable program, MESA.