Remains of a distant about the Homo sapiens were found in Indonesia’s Isle of Flores. Researchers believe that their small size was due island dwarfism.
The discovery dates back from 2003. The first found fossils were even smaller than a kindergartner child. Scientists estimate that the humanoid species lived on the Isle around 50,000 years ago, but recent findings indicate that the species may be at least 700,000 years old. The species, known as the “Hobbit,” measured one-third of a Homo sapiens, and their brain volume was at least half as massive.
The ‘Hobbit’ species is named Homo floresiensis, and they appear to be closer related to the Homo erectus than to the Homo sapiens. Homo floresiensis had large feet and shrugged shoulders, and they were supposedly able to craft primitive tools made out of stone.
The recently-found remains were six teeth along a piece of a mandible. These were found in a place known Mata Menge, 30 miles from the cave where the original specimens were unearthed. Researchers argue that both species are closely related even though they are thousands of years apart from each other.
The evolution of the Homo floresiensis
The theory is that larger hominids managed to get to the isle of Flores and then underwent a phenomenon known as “island dwarfing,” which refers to a particular species dwarfing as it is constrained ta an island habitat.
The lack of predators and reliable food sources are the main factors behind this phenomenon, which is displayed by some elephant species, also from the Isle of Flores. ItThis would be the first time that a species of hominid is known to have suffered from island dwarfing, but if it is true, then the species had only 300,000 years to evolve a relatively short period.
Another theory has suggested that the completest Homo floresiensis individual, dated 80,000 years old and named LB1, had Down syndrome. An analysis was carried on by Karen Baab, Ph.D., from Midwestern University in Arizona. It was determined that this was not true, and the team also managed to rebuild a 3-D model of the Homo floresiensis’ skull.
Although the remains do possess some of the physical indicators related to Down syndrome, most of the soft tissue that is usually affected by the condition does not fossilize. The team managed to have an idea of the shape of the LB1’s skull vault, the size of its brain, and its chin anatomy.
It was noted that some Turkish women that suffered from Down syndrome reached a similar size to LB1’s, but managed to grow taller as they became older. The skull of LB1 appeared to be much more primitive when compared to modern humans. Its estimated brain capacity was of 400 cm, a much lesser amount than other human species. The body has not been able to be efficiently reconstructed due to the lack of fossils.
Scientists noted that LB1’s leg bones were much shorter than pygmy people from Central Africa and the Philippines, which further points towards the phenomenon of island dwarfing. Researchers have been trying to link Homo floresiensis to a pathological origin, but the efforts have failed one after another, as it was impossible to connect the remains to diagnoses of down syndrome, dwarfism, and microcephaly.
Researchers continue to look for more fossils, mainly because there are still many unanswered questions. Some complain that there should be fossil remains of larger relatives to the Homo floresiensis, which would serve as evidence to the theory that proposes the migration of these hominids from the mainland to the isle.
The species’ origin is still unknown
Lead researcher Gerrit van den Bergh commented that he and his team expected the recently found fossils to be more closely related to the Homo erectus. The teeth were smaller than the specimens found back in 2003, but CT scans and subsequent analyses revealed that they did belong to Homo floresiensis. Van den Bergh also suggested that tsunamis may have brought the first specimens of Homo floresiensis to the isle.
Geological analyses of the isle point towards a possible extinction due to a volcanic eruption, around 12,000 years ago. That same eruption would have been the one that ended the life of the elephant species of Stegodon. Local stories of the Nage people, natives to the island of Flores, suggest that the Homo floresiensis may have lived longer, as they tell of small and hairy cave-dwellers that look just like the recently-discovered species. They are believed to be existent around the 16 century.
He pointed out that there is still much work to do, as most excavations in the search of hominid remains have been performed on the mainland and not on oceanic isles. The existence of Homo floriensis means that evolution is far from unidirectional.
It is possible that the diversity of the human genus extends farther than scientist were able to speculate throughout the years. Because evolutionary factors change depending on the environment, how humans developed on oceanic isles poses a challenge for future archaeologists.
Source: Nature