An Asian Genesis
In the dry, central part of Myanmar lies the Pondaung Formation, a series of geological deposits that have upended the story of human origins. For decades, the consensus was that anthropoids—the primate group including monkeys, apes, and humans—first appeared in Africa. But fossils unearthed here, dating to the late middle Eocene Epoch around 37 to 40 million years ago, suggest a different narrative. The discovery of several extinct primate species, including Pondaungia cotteri, Amphipithecus mogaungensis, and Bahinia pondaungensis, made this region a center for early primate diversification. An important find came in 2005 with the discovery of Ganlea megacanina, a 38-million-year-old primate that showed evidence for the "Out of Asia" hypothesis. This theory proposes that the earliest anthropoids evolved in Asia and later migrated to Africa. The fossils from Myanmar are older than the undisputed anthropoid fossils from Africa, challenging the long-held idea of an African genesis for our distant ancestors. These discoveries show that Asia, specifically the tropical floodplains of what is now Myanmar, was a site of primate evolution.
Dental Clues and Distant Cousins
The evidence from the Pondaung fossils comes from their teeth. Ganlea megacanina, whose name refers to the nearby village of Ganle and its own "mega canines," had exceptionally large and robust canine teeth. The crowns of these teeth show heavy, unusual wear patterns. This abrasion indicates they were not used for fighting but for prying open the hard shells of tropical fruits to eat the seeds inside. This specialized diet, known as seed predation, is seen today in modern anthropoids like South America's saki monkeys, linking Ganlea firmly to the anthropoid family tree.
Further evidence for an Asian origin comes from another small primate found in the same deposits: Afrasia djijidae. This 37-million-year-old animal, weighing only about 100 grams, is known from just four molar teeth. These teeth are important in their near-identical structure to those of Afrotarsius libycus, a primate that lived at the same time in Libya. The extreme similarity between fossils found thousands of miles apart suggests that a group of Asian anthropoids must have dispersed across the ancient Tethys Sea into Africa shortly before these animals lived. This migration likely seeded the subsequent evolution of primates on the African continent.