Predecessors of Early Humans Known as 'Hobbits' Shrunk Their Bodies to Adjust to Their Surroundings: Study

Human history, despite being one of the most analyzed subjects, has continued to surprise researchers at every turn. Homo floresiensis, also known as "Hobbit," was first discovered by researchers two decades ago through remains found in Liang Bua, a large cave in the highlands of the Indonesian island of Flores, CNN reported.

This discovery completely altered the understanding experts had regarding human evolution. A new study published in Nature Communications shares more revelations about the predecessors of Homo floresiensis.

The remains in Liang Bua were not of the primitive humans nor the Homo sapiens, CNN reported. The discovery showcased that there might be stages in the middle, that researchers had no idea about prior to the findings in 2003. The feature that captivated the researchers, the most about the remains, was its body size. The skeletal structure's body size was so small that people gave Homo floresiensis, the nickname, "Hobbit" a fictional race of diminutive beings in JRR Tolkien’s Lord of the Rings. 

Analysis revealed to experts that the remains were of a female specimen with a height of just over three feet and a weight of 66 pounds, CNN reported.

"We were all surprised by the fossil, because after cleaning it could be seen that the teeth had all grown and were intact. The skull bones also showed that it was an adult bone, not a child’s skull," said Indonesian archaeologist Thomas Sutikna, who was involved in the project.

The discovery by Sutikna and his team encouraged other archaeologists to delve deep into the Indonesian islands to search for more such remains of hominins, CNN reported.

A group of researchers recently published in their study about finding what they believe to be the smallest adult arm bone on record, on the island of Flores in Indonesia, along with two teeth fossils. Further analysis of the arm reveals that this being was even smaller than the one found in Liang Bua. The experts stated that the ancient human to whom this specimen belonged must have been around 6cm shorter than Homo floresiensis.

Digital microscopy of the fossil revealed that the remains were of an adult, as per the study. The complete humerus would have been 21.1 centimeters to 22 centimeters (8.3 inches to 8.7 inches) in length, the smallest human limb bone fossil ever found, CNN reported.

The group of researchers believe the specimen to be descended from another extinct human species known as Homo erectus. The findings prove that in the insular environment of islands, the species underwent extreme body size reductions, according to the study. 

The researchers believe that this size reduction occurred as a response to the conditions. "Perhaps, there was no need to be large-bodied, which requires more food and takes longer to grow and breed," said lead study author Yousuke Kaifu, professor at the University of Tokyo, CNN reported.

"The isolated island of Flores had no mammalian predators and other hominin species, so small-body size was OK." In their opinion, Homo erectus came large-bodied on the island and then went through size reduction to fit into the environment.

According to researchers, the size disparity between Homo erectus and Homo floresiensis, was fairly constant and points towards a natural variation as a means to adapt to the surrounding condition. Despite, being in the company of predators, the species was able to thrive on the islands for almost a million years, as per the study. Their small size, in all probability, helped in this achievement.

"The early dramatic reduction and subsequent stability of body size indicated that having a smaller body size on this isolated island was of benefit to the survival of these archaic humans," the study authors said in a statement, CNN reported.

Recent discovery of other small-bodied and small-brained hominins, Homo naledi in South Africa and Homo luzonensis in the Philippines, and the much larger, Denisovan has led experts to believe that more diverse species of humans existed before Homo sapiens, and many might have been coexisting with them.

Prior to the discovery of Homo floresiensis, the common belief was that only one species of human had evolved through time, with regional variation.

Matt Tocheri, Canada research chair in human origins at Lakehead University in Ontario hopes for more research on such remains to understand more about human evolution, CNN reported. In his opinion, these findings are important to figure out how the human species reached its present state.

"Every tiny fragment of Homo floresiensis or any other hominin is incredibly important," Tocheri said. "These fossils are our window to the shared evolutionary past of our species. Without them, we have no idea what was happening in the past."