PHYLOGENETIC-RELATIONSHIPS AND ORTHOGENETIC EVOLUTION OF COAT COLOR AMONG TAMARINS (GENUS SAGUINUS)

Orthogenetic evolutionary patterns may appear within taxa as a result of developmental constraints on the expression of genetic variation. M etachromism is a theory of variation in mammalian coat color that pred icts an orthogenetic evolutionary pattern. This theory was based in pa rt on studies of interspecific and geographic variation in the coat co lors of New World monkeys. We tested the theory of metachromism in tam arins (Saguinus) using phylogenetic information derived from mitochond rial DNA sequences. Parsimony analysis of mitochondrial DNA sequences from the D-loop and cytochrome b genes supports recognition of Saguinu s as a monophyletic genus composed of two major clades. Coat colors fo r 16 chromogenetic regions of the tamarin coat were examined using the molecular phylogeny to test predictions of the metachromatic theory. Our results support the hypothesis of an orthogenetic evolutionary pat tern for coat color in tamarins.