Comments on the Manhattan Stratigraphic Measure

POL, D.; NORELL, M.A.

CLADISTICS (PRINT)

Academic Press

Lugar: Oxford; Año: 2001 vol. 17 p. 285 - 289

0748-3007

The Manhattan Stratigraphic Measure was proposed as a measure of congruence between temporal information retrieved from the fossil record and a phylogenetic hypothesis. This index is based on the fit of a Sankoff character representing the stratigraphic ages of terminal taxa, and is calculated in a way analogous to the consistency index. Sample cases are analyzed in which this measure is insensitive to increasing amounts of conflict between stratigraphic and topological temporal information. A simple modification of the step matrix upon which the measure is based is proposed. The modified index, MSM*, overcomes the observed problem and is based on the measurement of the number and extent of ghost lineages.