A new ancient human that had lived for 50,000 years ago was found in the Callo Cave in the Philippines. The species dubbed as Homo luzonensis named after the island of Luzon in the country was found to be not directly related to other modern day human but rather an ancient relative.
The new discovery published in Nature raises questions about human evolution such as how the species arrived in the island and who are its ancestors.
"The remarkable discovery...will no doubt ignite plenty of scientific debate over the coming weeks, months and years," said Matthew Tocheri, associate professor of anthropology at Canda's Lakehead University in a review commissioned by Nature.
In the same cave, researchers from France, Philipines, and Australia found bones dating back 67,000 years in 2007. The type of the early human the bone which it came from is unknown. However, currently, the researchers discovered seven teeth and five different bones at the same site, dating back between 50,000 and 67,000 years. Based on their evidence, the discovered remains came from the unknown type of human.
"From the beginning, we realized the unusual characteristics of the fossils," said Florent Detroit, co-author of the study. "We completed the comparisons and it confirmed that this was something special, unlike any previously described species of homonins in the homo genus," he added.
They also observed that the teeth which they have found are a combination of elements from different early humans.
"It's a mixture that we haven't seen in other species," said Detroit, "and that was what told us, among other things, that this doesn't correspond to what we know totally, so we have described a new species."
Different questions and concerns about the discovery were raised such as how the Homo luzonensis got to the island which for researchers required a substantial sea crossing in order to get in the mainland.
Before, the discovery of Homo erectus which dispersed from Africa between 1.5 million to two million years ago was believed to stayed put in Africa. However, eight new discoveries changed the whole picture and showed that the new found human specie does not descend from it like the Homo Fluresiensis found in Indonesia in 2004, according to National Geographic.
For Tocheri, the discovery of Homo luzonensis provides more evidence that hints H.erectus is not the only the globe-trotting early hominin. Both the island-dwelling human species share almost the same characteristics with old human species in Africa, such as its foot bone that resembles those species existed in Africa around two to three million years ago.
They also found out that the Homo luzonensis might be climbing trees given that they had curved finger and toe bones. Nonetheless, for Detroit, it walked upright which proves it did not live on trees. Moreover, the remains also suggest that it is less than four feet tall.
The peculiar features of both the Homo luzonensis and that of the fluorosiensis from Indonesia are considered to be due to its environment. Further tests are needed to be conducted to confirm this theory and as of now efforts to extract DNA from it has been unsuccessful.
"One thing can be said for certain. Our picture of homonins evolution in Asia just got messier, more complicated and a whole lot more interesting," stated Tocheri.