Definition
Primate phylogeny is the evolutionary tree of the order Primates — the branching pattern of descent connecting prosimians (lemurs, lorises, tarsiers), New World monkeys, Old World monkeys, lesser apes (gibbons), and great apes (orangutans, gorillas, chimpanzees, bonobos, humans). It situates humans within a much larger mammalian clade and identifies our nearest living relatives.
Within the great apes, molecular data has resolved a once-contested topology: the human lineage split from the chimp-bonobo lineage around 6–8 million years ago, after both had separated from gorillas (~9 mya) and orangutans (~14 mya). Humans and chimps are sister taxa.
Why it matters
How it works
Early primate phylogenies were built from anatomy alone — skull shape, dental formulae, limb proportions. These produced reasonable but uncertain trees. The arrival of molecular phylogenetics from the 1960s onward transformed the field: protein sequences, then mitochondrial DNA, then nuclear genomes, each with thousands of independent characters, converged on a robust topology.
For the deep nodes, fossils and molecules now broadly agree. For the most recent splits — humans, chimps, bonobos — genome-scale data even resolves which parts of our genome are more like chimp than bonobo and vice versa, a fine-grained reading no morphology could provide.