Bones discovered in the cave of an island could belong to a new human species

The researchers announced on April 10 the discovery in the Philippines of fossils belonging to a species closely related to humans (Video: Rob Rownd / UPFI / UP-ASP)

Please welcome a new possible member of our group of standing monkeys: Homo Hulonensis, whose teeth and bones were discovered in the grotto of an island. The remains represent a new species, concluded the scientists in a report published Wednesday in the journal Nature. They called him Luzon, the island in the Philippines in which the remains were found.

Our kind, Homo in Homo sapiens, it contains multitudes, including neandertals of always sophisticated thick eyebrows and Homo erectus, a species of almost two million years that could be our direct predecessors.

Homo luzonensis is the fourth extinct human being and particular discovered in this century. The Homo floresiensis, so small that it was nicknamed "the hobbit", was discovered in Indonesia in 2004. The mysterious hominid of Denisovans, identified as a species through the bones of 39; a finger in 2010, lived in Siberia. The skeletons of Homo Naledi, with strange blends of primitive and modern features, were discovered in an African cave in 2013.

Together, these new species discovered showed that the evolution of the human being was extremely versatile, as groups adapted to conditions unknown in the world. Modern humans were not alone – our closest relative survived until recently. And some of our cohabitants may have gone on long voyages at sea, suggesting similar levels of intelligence.

"The evolution of our evolving group, Homo, is becoming more and more strange," he said. paleontologist Rick Potts, who leads the Smithsonian Human Origin program and did not participate in the research. Like Homo naledi, these fossils present a waste of new traits and features, Pott said. Their particular combination suggests that these humans were "previously unknown to science".

In 2007, Armand Mijares, an archaeologist at the University of the Philippines, asked his colleague Philip Piper to examine the animal bones mined by Mijares. Callao Cave in Luzon. The expansive cave is on the river plain. One of the limestone chambers is so large that it houses a Catholic chapel. A bone deposit at the entrance of the room dates back to the Pleistocene era, which began 2.6 million years ago and was completed 11,700 years ago.

Piper, a zoological archaeologist at the National University of Australia, has begun inventorying the remains of animals. "The second day, I was working with them," he says "I removed a human metatarsal". Piper immediately called Mijares to inform him of the unexpected discovery of the human foot bone by exclaiming, as he later revealed: "Oh my God, we have human bones here. "

Piper, Mijares and his team published a description of the foot bone in 2010. They knew that it was the remains of a human being who lived in the Philippines there are 67 000 years, depending on the amount of radioactive elements of uranium contained in the fossil. But the role of 2010 did not specify who owned this foot. "We did not know what it was then except that it was a human," said Piper.

Back in Callao cave, Mijares discovered other remains between 2011 and 2015. In total, scientists have extracted a dozen fossilized pieces cavity teeth, thigh bone, finger bones and feet, representing three individuals. Attempts to extract DNA samples from the remains have been in vain.

The body parts were tiny, they suggested that Homo luzonensis has not exceeded 1.20 in height. Their molars had modern forms. The way the leg muscle attaches to the femur is "typically human," Potts said.

The bones of his hands and feet were curved, "living portraits" of the bones of the feet and hands which belonged to the very old AustralopithecusPiper said. These hominids, such as Australopiteca afarensis from 3 million years ago, Lucy, had appropriate fingers to cheer.

These species lived at the same time as humans with modern anatomy, whose first fossil appeared 200,000 years ago (or maybe 350,000 years ago). "We continue to realize that a few thousand years ago, Homo Sapiens was not alone on Earth " According to the author of the study, Florent Detriot, paleontologist at the National Museum of Natural History in Paris.

Susan Anton, an anthropologist at New York University, a specialist in Homo erecus, was skeptical about the possibility that the remains came from a new species. The authors of the study "make no sense," said Anton, who has described it as "somewhat conservative and a little" lollified. "(The" lumpers ", unlike "splitters" are more reluctant to categorize fossils or living organisms as different species). The skulls, rich in anthropological details, would be more convincing.

Every difference in the shape of bones or teeth is subtle. "That's one of the reasons why we should be more careful said University of Wisconsin's expert in Madison, John Hawks, who helped direct the expedition to search the bones of Homo naledi and n? no connection with this discovery. But these differences, taken together, make the case of a new species "reasonable", he said.

The authors of the study they do not know how Homo luzonensis reached the island, With nearly 110,000 square kilometers, it is the 15th largest city in the world.

Even though these fossils are the oldest in the Philippinesthe proof of human existence is older; 700,000 years ago, ancient Luzon hunters captured rhinos with steel tools. What species were the ones that hunted is unknown.

Some "mammal species found in Luzon seem to have arrived from the mainland," said Piper. The Asian continent is located 650 kilometers or more from the Luzon Strait. But in the middle of the Pleistocene, when the glaciers solidified a large amount of water, The sea level has dropped to 122 meters, said Piper.

Strange weather events, such as tsunamis, may have allowed people to cross a prehistoric sea while clinging to debris, suggested Anton. "After climatic events or accidents, you can have particularly intelligent organisms that survive in places where they should not," he explained.

Hawks wondered if these humans were deliberately crossing the ocean. "I would say that when humans saw the land or smelled or knew the signs, like the birds that flew away from there, they looked for it," he said. "This is not a trait of Homo sapiens, it's something that our ancestors and our missing relatives had."

It is also possible that the first inhabitants of Luzon arrived of the Indonesian archipelago, jumping through chains of islands.

The cartoon version of the evolution, in which a curved monkey becomes a big and happy biped, suggests a journey with a destiny. The reality is more messy, especially when the species adapts to the islands.

The boundaries of an island can quickly cause evolutionary change; Charles Darwin saw this in finches. The small animals lengthen, the large ones narrow, the contrasts of light grow and pronounce themselves. "Think of the Galapagos Islands: each of the islands has its own kind of turtle," said Piper.

"The isolation has its games" Potts said. Homo floresiensis showed anthropologists that an island could be "a strange little laboratory of human evolution," he said. These bones reinforce this lesson.

"He's starting to look like the process of evolution is really fluid " Potts said. "And it is surprising that it is so fluid when each homo species can actually have a story or record, the result is a fusion of the modern and the old: molars that can be yours to side of the curved toes of millions of people. " of years ".

"Is it possible that other human species evolved in these island labs and that their fossils are waiting to be discovered? I would not be surprised," said Piper.

According to Hawks, anthropologists have attributed the worldwide success of Homo sapiens to our modern anatomy fifteen years ago. These new discoveries, in remote corners, suggest that Exceptionalism is not built into our brain or our skeletons.

"The archaeological record now shows us that the old human forms were much more adaptable, and I would say smart, from what we imagined, "said Hawks. This is not 'Flowers for Algernon & # 39; "Suddenly, we are super smart and everyone in the world is behind us. "The scientists now they are studying genomes that provide further clues about the survival of Homo sapiens, by observing our metabolism or our resistance to the disease." I would say that the doors have been opened and we We have not discovered where they lead. "