Evolutionary Relationships Among the Gibbons: A Biogeographic Perspective

Abstract

The debate regarding gibbon taxonomy and phylogeny has flourished for well over one hundred years. The first gibbon, Homo lar, was described by Linnaeus (1771); the siamang as Simia syndactyla by Raffles (1821); the first concolor gibbon as Simia concolor by Harlan (1826); and the hoolock as Simia hoolock by Harlan (1834) (Groves 1972, 2001). Throughout the 19th century, gibbon nomenclature diversified until, by the end of the century, most of the taxonomic names and divisions recognized today had been established. Phylogenetic relationships amongst these taxa have continued to cause discussion and debate, with the advent of molecular methods only serving to accelerate the discourse. In contrast, there has been startlingly little research into the biogeographic history of gibbons, largely due to their incredibly sparse fossil record. This chapter will outline current views regarding gibbon taxonomy, phylogeny, and biogeography, providing an overview of the main areas of consensus and continuing debate.