New theory on Hobbit species has drastic implications for Out-of-Africa theory

A controversial new theory published in the journal Nature suggests that the remains of Homo floresiensis, nicknamed the Hobbit for its small stature, do not belong to the Homo lineage at all, but rather are descended from a more ancient pre-human group called Australopithecus. It was always assumed that Homo sapiens were the only hominid species to have left Africa. But what if other species also made the journey and left their mark on the world and perhaps even our DNA?

The ‘Hobbit Human’ was first discovered in October 2004, when an excavation of fragmentary skeletal remains from the island of Flores in Indonesia yielded what was called ‘the most important find in human evolution for 100 years.’ Its discoverers dubbed the find Homo floresiensis, a name suggesting a previously unknown species, dated to have lived between 95,000 and 17,000 years ago – that means the Hobbit lived at the same time has modern humans and appears to be the latest surviving human species, aside from our own. It is estimated to have had a height of around 3 feet 6 inches.

Cave where the remains of Homo floresiensis were discovered in 2004, Lian Bua, Flores, Indonesia. (Wikipedia)

Ever since its discovery exactly one decade ago, Homo floresiensis has been the subject of much debate and intense research to determine whether they represent a species distinct from modern humans, or whether the remains belong to a modern human (Homo sapien) with a disorder such as microcephalia, a condition characterized by a small head, short stature and some mental retardation. [Read previous: ‘Fierce scientific debate has erupted over identity of Hobbit species’]

Modern human and Homo floresiensis (‘Hobbit’). (fineartamerica.com).

Discovery News reports that the prevailing theory is that “the Hobbit was a member of our family tree, belonging to the genus Homo and having descended from a population of Homo erectus that made its way to the island and shrunk in stature over evolutionary time due to the “island effect.” (Because islands are relatively closed communities, evolution tends to lead to smaller forms.)”

A facial reconstruction of Homo floresiensis from a skull that was recovered in Flores (Wikipedia).

But now a new perspective has been thrown into the mix. According to the latest commentary in Nature, this human-like species might not have been human after all. Renowned paleoanthropologist Chris Stringer from the Natural History Museum in London, suggests that the Hobbit species did not belong to the Homo lineage but was descended from Australopithecus, a genus of hominids that evolved in eastern Africa around 4 million years ago, spread out across the continent, and eventually became extinct around 2 million years ago.

Stringer explained that the jaw and chin of the Hobbit skull resemble pre-human fossils of more than 2 million years ago, while the body shape and small cranial capacity look more primitive that those in the Homo genus. 

Skull belonging to Homo floresiensis, which Chris Stringer believes is more similar to the Australopithecus genus. (Wikipedia).

“This presents a real mind blower,” writes Discovery News. “We’ve tended to assume that only Homo sapiens left Africa, interbred with locals in Europe and Asia (like Neanderthals and Denisovans), resulting in today’s non-Africans. But what if other species, like Australopithecus, also left Africa, made it to places like Indonesia, and successfully settled there until more recent times? The plot thickens.”

If this is the cases, the Hobbit species may have also interbred with other hominids, causing further complexity to an already confusing family tree. Research last year revealed that the genome of one of our ancient ancestors, the Denisovans, contains a segment of DNA that seems to have come from an another species that was neither human nor Neanderthal. Could Homo floresiensis provide a missing piece to the puzzle? [Read related: ‘Ancient humans bred with completely unknown species’].

“If the H. floresiensis lineage had a more primitive origin than the oldest known H. erectus fossils so far identified in Asia, then we would have to re-evaluate the dominant explanation for how humans arose and spread from Africa,” Chris Stringer wrote. “It would mean that a whole branch of the human evolutionary tree in Asia had been missing.”

Featured image: Reconstruction of Homo floresiensis by Atelier Daynes Paris. Photo by Plailly/ Australian Museum

By April Holloway