7-8-2024 (JAKARTA) Researchers have unearthed fossilised fragments of a diminutive upper arm bone on Indonesia’s Flores island, solving the long-standing mystery of the origins of Homo floresiensis, colloquially known as ‘The Hobbit’.
The incomplete humerus, measuring a mere 88 millimetres in length, was initially misidentified as a crocodile bone fragment when excavated at the Mata Menge site in Flores’ So’a Basin. However, subsequent analysis revealed its true significance as the smallest known limb bone of any member of the human evolutionary lineage.
Dating back approximately 700,000 years, this fossil, along with two teeth found at the same location, has provided crucial evidence supporting the theory that Homo floresiensis descended from Homo erectus, a larger-bodied human ancestor that originated in Africa and later spread across Asia.
Professor Yousuke Kaifu, a palaeoanthropologist at the University of Tokyo and lead author of the study published in Nature Communications, explained, “This discovery indicates that Homo floresiensis underwent a dramatic reduction in body size from its Homo erectus ancestors, whose stature was similar to modern humans.”
The fossils bear striking similarities to Homo erectus remains found on the nearby island of Java, dating from 1.1 million to 800,000 years ago. This connection strongly suggests that a group of Homo erectus individuals somehow reached Flores, possibly over a million years ago, and subsequently experienced a process known as island dwarfism.
Dr Adam Brumm, an archaeology professor at Griffith University’s Australian Research Centre for Human Evolution and co-author of the study, elaborated on this evolutionary phenomenon: “Island dwarfism is a process where larger mammals, including humans in this case, gradually reduce in size over generations when isolated on islands. This adaptation is likely driven by periodic food shortages, making smaller body size advantageous for survival.”
Based on the size of the humerus, researchers estimate that this early Homo floresiensis individual stood at approximately one metre tall, slightly shorter than the famous 60,000-year-old Homo floresiensis specimen discovered in 2003 at the Liang Bua cave site.
The find at Mata Menge represents the first Hobbit bone beyond the cranium identified at this location. In total, ten Homo floresiensis fossils from at least four individuals have been excavated from the site’s sandstone deposits, along with stone tools. Intriguingly, these earlier specimens suggest that the Hobbit’s ancestors were even smaller than their descendants.
Professor Gerrit van den Bergh, a palaeontologist from the University of Wollongong and study co-author, noted the significance of this size progression: “The Mata Menge fossils provide a crucial snapshot of the evolutionary process that led to the Homo floresiensis we know from later periods.”
The extinction of Homo floresiensis coincides with the arrival of our own species, Homo sapiens, in the region. Dr Brumm speculates that our ancestors may have played a role in the Hobbit’s demise: “The timing of their disappearance shortly after Homo sapiens established a presence in the area seems unlikely to be mere coincidence.”
