Who are the mysterious people of history

Did this mysterious ape-man live by our side?

Warren Sharp, a geochronologist at the University of California, Berkeley, who was not involved in the study, commends the team for their thorough and careful efforts. However, he emphasizes that the team's maximum age estimate requires a model of cave radioactivity and its evolution over a long period of time - an extremely difficult proposition. Therefore, this estimate is naturally less convincing.

ANOTHER LIGHT IN THE DARK

Berger and his colleagues also announced on Tuesday that there was a second chamber with fossils in the Rising Star Cave H. naledi gives. It was discovered in 2013 during field studies by Steven Tucker and Rick Hunter - the same cave climbers who made the first find in the chamber called Dinaledi.

The second chamber is called Lesedi - the Setswana word for "light" - and is more than 90 meters away from the Dinaledi chamber, which contains more than 1,500 fossil parts of the H. naledi housed.

So far, an additional 130 parts have been recovered from the Lesedi chamber that belong to two adults and at least one child. One of the adult skeletons, presumably a male, is remarkably well preserved. It contains a skull in which a large part of the facial bones has been preserved, and thus provides important information that was missing when it was originally found. So it's no wonder the team christened the individual Neo, from the Sesotho word for “gift”.

"[Neo] is in as good a condition as the Lucy skeleton," says Hawks, referring to the famous, fully preserved 3.2 million year old skeleton of one Australopithecus afarensis from Ethiopia. "We're missing a few pieces that Lucy received, and we've got a few pieces that Lucy doesn't have."

EVIDENCE

The discovery of the Lesedi Chamber provided Berger's team with some underpinning of one of his most hotly contested hypotheses: that H. naledi somehow used the Rising Star cave system to dispose of his dead.

This bold theory arose from the general weirdness of the Dinaledi chamber, which the Lesedi chamber also exhibits. Both chambers contain almost exclusively the remains of H. naledi, which is highly unusual (although some animal remains have also been found in the Lesedi chamber). In addition, Berger and his colleagues have not yet found any further entrances to the chambers.

However, many scholars want to see more evidence before even considering this thought. “Many experts (including myself) believe that such complex behavior is unlikely in a being whose brain was about the size of a gorilla's. Even more so if you presumably have to assume that fire (for lighting) is used in a targeted manner, ”says Chris Stringer, an anthropologist at the Natural History Museum in London who has reviewed the newly published studies.

In addition, other archaeologists as well as members of the team warn that the dead should be disposed of by H. naledi does not necessarily have to be motivated by human-like rituals or reasons.

"We think of people that they are very smart and have reasons for things," says Hawks. "I'm not thinking of common sense - a very simple measure, for example, is to ensure that the corpses are not eaten by predators or exposed to the elements."

TIME AND PLACE

Berger and his team have not yet dated the remains from the Lesedi chamber, and the dates from the Dinaledi chamber do not show how long-lived H. naledi than Art actually was. The short period of time that dating offers, however, belongs to the beginning of the Middle Stone Age. In that era the genus was homo another broad, tangled bush - not the trimmed lineage of a single species as we see it today.

230,000 to 330,000 years ago there were not only ancestors of anatomically modern humans on earth: In Europe and Asia there were the Neanderthals, in Asia the Denisova humans, presumably small areas in Eurasia with our ancestors Homo erectus as well as predecessors of the H. floresiensis. In the midst of this pantheon would be H. naledi the first known species to live in Africa at the time, apart from some scattered references to archaic forms of the H. sapiens.

It is not yet clear how exactly H. naledi fits into the human family tree. Most researchers agree that the direct ancestor of the Homo sapiens Homo erectus which first appeared 1.8 million years ago. According to one of the analyzes by Berger and his colleagues, it could H. naledi however, due to its morphology, it would be a better candidate for the youngest ancestor of humans. The species may have evolved in parallel with the modern human branch after that branch emerged from it.

Other scientists believe it is more likely that the remains from the Rising Star Cave form a sub-branch of human ancestors that survived in an enclosed area - similar to H. floresiensis on his island retreat.

Berger's team also argues that when H. naledi and modern humans the stone tools from that period found in South Africa may not be the work of humans. “We assumed that [toolmaking] was a sign of modern, human complexity. In fact, this is a region of the world where naledi is the best documented hominini representative, ”said Hawks.

The Rising Star team also concludes that H. naledi could be a sign that the part of Africa south of the equator is the driving force behind the early hominini diversity. This assumption is in stark contrast to the claim that East Africa was the cradle of early human evolution. This theory is based on rich fossil records in Ethiopia, Kenya and Tanzania.

Bernard Wood, a paleoanthropologist at George Washington University, believes that the debate is about the origin of the homo-Grade could get unnecessarily heated one way or another.

"We have to make sure that we are not falling into the trap of assuming that all major events in hominini evolution happened where we were lucky enough to find fossils," says Wood. “It makes little sense to overturn one misguided Garden Eden hypothesis by another, equally misguided Garden Eden hypothesis. We should relax, take a deep breath [and] celebrate the fact that these are interesting findings. "

As it stands, the Rising Star Cave will continue to offer reason to celebrate in the years to come. Hawks suspects that less than five percent of the Dinaledi chamber has been excavated so far. The Lesedi chamber probably also contains other remains. The team is also exploring other nearby cave systems for traces of our old cousins.

“That should also motivate people not to give up hope of [new] discoveries,” says Marina Elliott, who is part of the team. "Exploration is not dead."

Jamie Shreeve contributed to the coverage. This article has been shortened for the sake of clarity.