A recent paper in Nature Communications discusses specimens recovery from Flores, Indonesia and describes a particularly small adult limb bone. Ranging between 700,000 years, these new discoveries help in understanding more about the evolutionary process of Homo floresiensis or the ‘Hobbits’ as found in Flores, Liang Bua cave since 2003 under the discovery team of archaeologist, Professor Mike Morwood (1950-2013).
Linguistic and morphological studies imply that these pygmies having a lower brain capacity than modern humans lived in Liang Bua until as late as 50,000 years ago when the Homo sapiens had colonization Australia which is to the south of Flores.
This is true according to the details regarding the subject origin of Homo floresiensis that has been widely discussed. First preconceptions as to Homo floresiensis, based on Ardi, was that Homo floresiensis was a small bodied, relict population of early Asian Homo erectus. Another theory suggested that the ‘Hobbit’ could be a neotenic individual who might be delayed in development or a female like Neanderthals or the result of hybrids with homo sapiens or, in fact, could be a late surviving species from Africa like homo habilis or Australopithecus afarensis ‘Lucy’.
Other than Liang Bua, there are only reported hominin fossils on Flores coming from Mata Menge, an open air site that is approximately 75km to the east of the cave in So’a Basin. Previoulsly, research conducted at this site has recovered several hominin fossils, such as a jaw fragment and six teeth, from the played sandstone aged at about 700 000 years. These fossils are 650000 years older than the Liang Bua hominins and represent at least three individuals with even smaller jaws and teeth than the Homo floresiensis, hence implying early attainment of small body size in Flores hominins.
Still, there was no possibility to clarify some facts concerning the body size of these hominins because, despite the numerous remains of the Mata Menge, postcranial elements were missing (the bones located below the head). The new study by Prof Yousuke Kaifu of the University of Tokyo, Iwan Kurniawan of the Center for Geological Survey in Indonesia and the University of Wollongong’s Associate Prof Gerrit van den Bergh has unearthed three more apparent hominins at Mata Menge, an increase by a distal shaft of an adult humerus, the lower half of the upper arm bone.
This find is critical in understanding the evolutionary history and the beginning of Homo floresiensis. When observing its microstructure by the help of digital microscope, it is revealed that the fossil is of the adult. By applying the estimated length of the bone to the rest of the limb proportions and using a brachial index of 0.77, the team hoped weight and height estimate of the hominin was around 100 cm high, which if true is 6cm under the height of the 60 000-year-old Homo floresiensis discovered in the Liang Bua cave in Indonesia.
’This Right, a 700,000-year-old adult humerus is not only significantly smaller compared to the humerus of Homo floresiensis but also the shortest upper arm bone discovered thus far in the entire hominid fossils records globally’ said Professor Adam Brumm from Griffith University’s Australian Research Centre for Human Evolution a co-author of the paper. For our working theory that Homo floresiensis’ forebears were morphologically neo-Darwinian ‘bantamised’ that is: much diminished in body size this new find vindicates our hypothesis, Nevertheless, the diminutive stature of this limb bone indicates that the early direct antecedents of the ‘Hobbit’ may well have been potentially even tinier than as formerly estimated.
Two more homin teeth found in Mata Menge also belong to small statured specimen indicating that this creature was an early Homo erectus of Java and the theory that Homo floresiensis is evolved from early, primitive homin does not hold good.
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