Toward a phylogenetic classification of Primates based on DNA evidence complemented by fossil evidence.

A highly resolved primate cladogram based on DNA evidence is congruent with extant and fossil osteological evidence. A provisional primate classification based on this cladogram and the time scale provided by fossils and the model of local molecular clocks has all named taxa represent clades and assigns the same taxonomic rank to those clades of roughly equivalent age. Order Primates divides into Strepsirhini and Haplorhini. Strepsirhines divide into Lemuriformes and Loriformes, whereas haplorhines divide into Tarsiiformes and Anthropoidea. Within Anthropoidea when equivalent ranks are used for divisions within Platyrrhini and Catarrhini, Homininae divides into Hylobatini (common and siamang gibbon) and Hominini, and the latter divides into Pongina for Pongo (orangutans) and Hominina for Gorilla and Homo. Homo itself divides into the subgenera H. (Homo) for humans and H. (Pan) for chimpanzees and bonobos. The differences between this provisional age related phylogenetic classification and current primate taxonomies are discussed.

Primate phylogeny: morphological vs. molecular results.

Our comparative study of morphological (our data on selected living primates) and molecular characters (from the literature) confirms that, overall, phylogenetic reconstructions of Primates, and consequently their classifications, are more similar than dissimilar. When data from fossil Primates are incorporated, there may be several possible relationships among living Primates; the difference between most of them hinges mainly on the position of Tarsius. In one hypothesis, tarsiers are closely related to lemurs and lorises, and thus Primates is divided into Prosimii [lorises, lemurs, and tarsiers] and Anthropoidea [Platyrrhini and Catarrhini, i.e., monkeys, apes, and humans]. Two additional alternatives are that Tarsius is a sister group to the clade embracing lorises + lemurs and Anthropoidea and that in which all three lineages (Tarsius, lorises + lemurs, and Anthropoidea) form a polychotomy. In another hypothesis, tarsiers are closely related to anthropoids, giving these two branches: Strepsirhini [lemurs, lorises] and Haplorhini [tarsiers and Anthropoidea (Platyrrhini, the New World monkeys, and Catarrhini, Old World monkeys and Hominoidea)]. The first three alternatives gain some support from the fossil record, and the fourth from morphology of the living Tarsius and molecular data. It is emphasized that the morphological characters employed in this study for Tarsius are based on the only surviving genus of once-diverse tarsiiform primates known from the Eocene, and, although considered a "living fossil," it cannot represent all of them. Furthermore, Tarsius embodies derived features of its own which may affect its systematic position, but not necessarily the position of Tarsiiformes. Although the early Tertiary adapoids might have more nearly resembled anthropoids in their biochemistry and placental developments, this hypothesis is not testable from fossils, and any inferred relationships here must be based on characters of skeletal anatomy. Alternatively, anthropoids may be derived from certain omomyids or from some as yet undiscovered Eocene African taxon. Close relationships among Homo, Pan, and Gorilla have been confirmed during recent decades; Pongo is the sister group to this trichotomy. With increasing molecular data, Homo and Pan appear to be closer to each other than to any other living hominid taxon. Gorilla is a sister group to the Homo-Pan clade and Pongo is a sister group to all of them. Morphologists have given limited evidence for such a dichotomous grouping. In this study, we support the Homo-Pan clade, although with characters not as strong as for other clades.

Karyotype polymorphism in the slender loris (Loris tardigradus).

Three wild-caught Sri Lankan and two captive-bred slender lorises (Loris tardigradus) in Adelaide Zoo, South Australia, were karyotyped from leucocyte cultures. The founder male and one of the founder females were of the grey subspecies L. tardigradus grandis, of which L. tardigradus nordicus is probably a synonym. The other founder female was a small red-brown L. tardigradus tardigradus. All three wild-caught individuals were karyotypically distinct from each other and their offspring showed the expected heterozygosity. The L. tardigradus tardigradus karyotype was no more distinct from the grey subspecies karyotypes than they were from each other. On present evidence, Indian and Sri Lanka lorises appear to be chromosomally distinct.

Systematic relationships of gorillas from Kahuzi Tshiaberimu and Kayonza.

Previous classifications of gorillas from Mt. Kahuzi, Mt. Tshiaberimu and the Kayonza Forest, placing them in Gorilla gorilla graueri or G.g. beringei, somewhat over-simplify a complex situation. Both Kahuzi and Tshiaberimu gorillas are close to graueri and should be placed in that subspecies, but each (in different ways) shows some approach to beringei, either through independent adaptation to extreme montane conditions, or because they may be points along a (now disrupted) cline from one race to the other. A hypothesis for the dispersal of beringei is presented, making use of geophysical data on the movement of the African plate over the Virunga 'hot-spot'.