Study Finds Humans More Closely Related to Orangutans

The latest issue of the Journal of Biogeography holds one of the most interesting hypotheses of this year – namely the theory that humans are not as much related to chimpanzees as previously stated, but rather to orangutans. The new paper, written by scientists at the University of Pittsburgh and the Buffalo Museum of Science, also argues that fossil evidence does not support the popular belief that we share a common evolutionary root with chimps. Despite DNA evidence, which points to the contrary, we are more different from chimpanzees than we are from orangutans, the team says.

“They have good morphological evidence in support of their interpretation, so that must be taken seriously, and if it reopens the debate between molecular biologists and morphologists, so much the better. They are going against accepted interpretations of human and ape relationships, and there's no doubt their conclusions will be challenged. But I hope it will be done in a constructive way, for science progresses by asking questions and testing results,” the former head of the Human Origins department at the London Natural History Museum, Anthropologist Peter Andrews, says of the new research.

The study was led by UP School of Arts and Sciences Anthropology Professor and President of the World Academy of Art and Science, Jeffrey H. Schwartz, working in collaboration with the Buffalo Museum Director of Science John Grehan. According to it, fossil evidence, as well as measurements conducted on living primates, seem to indicate that humans, orangutans and other early apes belong to an evolutionary group that is different from that including gorillas and chimpanzees. This naturally means that we cannot share the same root as chimps do, as we, as a species, evolved differently.

In an analysis of 63 physical characteristics, which were taken as reference points between humans, chimps, gorillas and orangutans, the researchers discovered that we shared 28 of them with orangutans, only two with chimps, and seven with gorillas. When taken as a single group, the three primates share three traits with humans. To put things into perspective, gorillas and chimps share 11 physical similarities.

“Palaeoanthropology is based solely on morphology, and there is no scientific justification to favor DNA over morphological data. Yet the human-chimp relationship, generated by molecular data, has been accepted without any scrutiny. Grehan and Schwartz are not just suggesting an orangutan–human relationship – they're reaffirming an established scientific practice of questioning data,” Arizona State University (ASU) International Institute for Species Exploration researcher Malte Ebach concludes. “They criticize molecular data where criticism is due.”