By Andrea Hargraves 
Researchers have found new fossils of a metre-long hominin known as the “Hobbit” that lived on the island of Flores in Indonesia. The upper arm bone and teeth now join other rare specimens of homofloresis. Hey Stady Published in the magazine nature This Tuesday (6) also brings new evidence about the ancestors of this species.
First fossil discovery H. floresiensis That happened in 2003, when researchers found a nearly complete individual dating back about 100,000 years in Liang Bua Cave, also on Flores. The newly discovered fossils were excavated at the Mata Menge site and are even older, dating back 700,000 years.
The new evidence shows an adult individual that was six centimeters shorter than the one found at Liang Bua, the study concludes. According to Yusuke Kaifu, the author of the article and a professor at the University of Tokyo, the research points to a scenario of a significant reduction in size during the first 300,000 years of hominin presence on the island.
The tools found at the site date back to one million years ago. A possible hypothesis is that these were the products of early hominins at the site, who led to the emergence of H. Florensis – Humans are compatible with humans and their ancestors.
The rapid decrease in size was followed by a long period of stable short stature. “This may mean that small body size was good for H. floresiensis “Until their extinction,” explains Kaifu. The end of these humans coincides with the arrival of rational human Region.
The drastic reduction in size can be explained by the “rule of islands.” According to this idea, animals that colonize areas with limited resources have the advantage of being smaller. Smaller individuals do not need to feed as much and take less time to grow and start reproducing.
The fossils that resulted from the study published Tuesday were not the first to be found. H. floresiensis At the Mata Mengi site. Fragments of teeth and jaws had previously been recovered from the site. However, the discovery of an upper arm bone of an adult made it possible to calculate its height.
“The upper arm bone is not a perfect piece compared to the femur, but we can still calculate potential height using known relationships between upper arm size and height in humans and apes,” Kaifu said. However, it cannot be concluded that the species that lived 700,000 years ago were shorter than those that lived 60,000 years ago, because the sample available is small.
For researchers Mercedes Okumura and José Alexandre Diniz Filho, one of the main contributions of the article is to validate H. floresiensis As a species – they did not participate in the study.
Because of its atypical features, the first fossil discovered in 2003 sparked debate that the bone belonged to a living creature. rational human With some diseases, such as microcephaly. However, the place where the fossil was found underwent a change in dating and moved from 30 to 14 thousand years ago to 100 thousand years ago. At that time, Haa' of the wise It has not yet reached Southeast Asia.
“[O estudo] “It reinforces the idea that this species has existed for a long time and was already a dwarf species, which reinforces the idea of ruling the islands,” analyses Professor of Ecology and Evolution José Alexandre Diniz Filho, from the Federal University of Goiás (UFG).
Where does H. floresiensis come from?
Origin H. floresiensis It has also been widely discussed in science. A recently published study confirms the most widely accepted hypothesis today, according to which this species came Homo erectusthe first hominins to leave Africa. But when it occupied Flores, this species was roughly the same length as Haa' of the wiseIn addition to having a skull that is almost twice the size of the skull. H. floresiensis.
Some scholars argue that the “hobbits” came from homo habiliswhere they had similar height. You H. Habilis His skull size was also smaller than that of his. h. erectHowever, nothing remains of it. Habilis Outside Africa. In the new study, the researchers concluded that the characteristics of teeth and bones are very similar to those of h. erect.
The advantage is that Habilis And the h. erect “There are many specimens,” explains Mercedes Okumura, professor of biological sciences at the University of São Paulo (USP). “When you find a few, like the ones in H. floresiensisYou can compare with some certainty.”