Ancient primate shifts human origins
2 Sep 2009 by Evoluted New Media
Did our evolutionary ancestors come from Asia and not Africa?
Did our evolutionary ancestors come from Asia and not Africa?
A group of scientists claim that the common ancestor of humans, monkeys and apes originated in Asia, and not in Africa.
The international team of paleontologists has shown that these primates, which are 37 million years old and named Ganlea megacanina, had an ability observed today in modern monkeys - they pried open and ate seeds in a specific way by using their greatly enlarged canine teeth.
Why is this so important? Well, this ability is one of the reasons that justify species being placed in the family of anthropoid primates – the lineage that gave rise to humans.
“Ganlea megacanina shows that the first anthropoids originated in Asia rather than in Africa,” said French paleontologist Professor Laurent Marivaux who together with Professor Jean-Jacques Jaeger led the research.
In primates, there exist two major lineages - anthropoid primates (monkeys, apes and humans) and prosimians, considered to be more primitive and whose best-known representatives today are lemurs. Until now, scientists assumed that anthropoid primates originated in Africa.
Working together with several colleagues, Marivaux and Jaeger have for the past 20 years been carrying out excavations in Asia, specifically in China, Thailand, Pakistan and Myanmar (formerly Burma), where they started exploring in 1999. In November 2005, the researchers discovered several fossils in central Myanmar dating from 37 million years ago and belonging to a new species of primate - Ganlea megacanina. In November 2008, part of the lower jaw of one member of this species was discovered – a find that provided the paleontologists with powerful evidence supporting an Asian origin for anthropoid primates.
The new primate has greatly enlarged canine teeth which show heavy abrasion, indicating that Ganlea megacanina used them to pry open the tough exteriors of tropical fruit in order to extract the nutritious seeds contained inside. This is an unusual form of feeding adaptation that has never been observed in prosimian primates such as lemurs.
Ganlea and its closest relatives inhabited Myanmar 37 million years ago during the Eocene period, in a tropical flood plain that was very similar to the modern Amazon Basin. They belonged to an extinct family of Asian anthropoid primates, the Amphipithecidae. Four other amphipithecids had previously been discovered in Asia - two in Myanmar, one in Thailand and one in Pakistan. A detailed analysis of their evolutionary relationships shows that they are closely related to today's anthropoid primates, and that the Myanmar forms evolved from a single common ancestor.
The expeditions were the fruit of a long-lasting collaboration between scientists from several academic institutions in Myanmar with the University of Poitiers via IPHEP, ISEM, the Carnegie Museum of Natural History in Pittsburgh, and the Department of Mineral Resources in Bangkok, Thailand.
