Abstract
Molecular phylogenetic analyses have established most components of primate systematic classiications, which are signiicantly diferent from the traditional morphology-based classiications. This becomes an issue when inferring the phylogeny of extinct taxa, for which molecular data are usually unavailable. Researchers have attempted to extract phylogenetic signals from morphological characters to infer relationships between extant and extinct taxa. One of the most disruptive factors obscuring phylogenetic signals of morphological characteristics is size-related shape variation (i.e., allometry). Although some issues remain, researchers have successfully detected phylogenetic information that was previously hidden by the strong efects of allometry. Recently, the importance of morphological data and fossil evidence has been reconsidered, and the total-evidence approach has been resurrected. This approach incorporates both extinct and extant taxa and uses all available data, i.e., both molecular and morphological characters. The validity of the total-evidence approach should be evaluated under various conditions using simulation studies and tested using the actual data for various primate taxa.
