The discovery of Homo naledi, another human species that preceded humans!
A paradigm that overturns stereotypes about human origins and evolution
Netflix original documentary series [Unknown: The Bone Cavern]

What comes to mind when faced with the topic of human origins and evolution? Perhaps we think of "The March of Progress," a widely known illustration often used as a reference in textbooks and other books, and "Homo sapiens," our ancestors. For a long time, we understood and explained human evolution as a linear progression from apes to modern humans, culminating in Homo sapiens, our ancestors.
But it's half right and half wrong.
We never evolved in a straight line, like a march of progress, and our relatives evolved along a branching tree rather than a linear line.
Especially during the latter half of human evolutionary history, during the last 3 million years, numerous characters belonging to the genus Homo (human) appeared and disappeared on the stage.


However, in 2013, a new species of human, Homo naledi, whose existence had been unknown because it was buried deep in a cave, was discovered as a fossil in Africa, where Homo sapiens, also known as 'modern humans', is known to have emerged.
Several lines of evidence have also been discovered showing that behaviors once thought to be exclusive to Homo sapiens are not exclusive to Sapiens.
"Cave of Bones" explores why and how the discovery of Homo naledi, a momentous event, brought such a shock and controversy to the history of human evolution, and seeks to define and examine the existence of this new species of human, Homo naledi.


Above all, what sets this book apart from other anthropology books is that it vividly portrays the cave excavation process and struggles of the paleoanthropologists who discovered Naledi and worked to spread its value.
This book, which offers the fun of reading an archaeological adventure, will make you feel like the main character of [Indiana Jones], regardless of age or gender.
As you experience the sensation of being sucked into a dark, narrow, and deep cave, you will encounter a new and exciting experience where the story of human evolution and the origins of humanity, which you usually found boring, comes to you.

This time, I was about to enter the Dinaledi cave myself.
In recent months, our expedition has uncovered what appears to be a remarkable clue that could revolutionize the search for human origins.
It seemed that we were finally standing on the threshold of understanding our distant cousins, the paleohumans, and of recognizing who we, the humans living today, are.
So, I decided to take the risk and leave the command center, bravely pass through the suit, and step into the amazing underground space.
(…) The Rising Star cave system rewrote the human family tree with thousands of fossil bones.
And it changed the course of my life.
--- p.10, from "Prologue"

The 'March of Progress' is a symbol of human evolution.
It is a symbol that can be seen everywhere.
And it's the wrong symbol.
We did not evolve in a straight line.
Our relatives discovered as fossils do not form a straight line, but rather a branching family tree.
Even in the 1960s, when Prehistoric Man was published, paleoanthropologists already knew that our ancestors and relatives branched out in various ways within the family tree.
Of course, scientists have had numerous challenges figuring out exactly how the various fossil hominins are related to one another, and much remains a mystery.
But no one thought that all fossil humans could be lined up in a line from ancestor to descendant.
--- p.30, Chapter 2.
From “The Family Tree of Humanity”

However, this species was a strange creature, relatively tall and thin compared to other ancestors, yet strong, as evidenced by muscle traces and joint size.
On top of this long-legged, hunchbacked body was a small head with a brain slightly larger than that of a modern chimpanzee.
By classifying this creature, whose body shape resembles a nail, as Homo, we have broken the lower limit of brain size that most scientists thought was acceptable for Homo.
(…) The way the bodies of the rising star hominins adapted to their environment generally pointed in the same direction as other Homo species.
Therefore, we conclude that this species must belong to the genus Homo.

--- p.65, Chapter 3.
From "In Search of Homo Naledi"

Based on scientific evidence, we have established a precise date range for Homo naledi and estimated the age of the Rising Star fossil to be between 335,000 and 236,000 years ago.
This regiment was a shock.
Given Naledi's anatomical structure, it is surprisingly recent, but it also represents a significant period in the evolutionary history of Africa and humanity as a whole.
(…) Until then, most researchers assumed that there were no other humans in Africa when Homo sapiens first evolved.
But now another species has emerged: Homo naledi.
Could this species have been capable of sophisticated behaviors that scientists thought were unique to our species?
--- p.71~72, 「Chapter 4.
From "The World Meets Naledi"

Within days of our first expedition, we had reason to suspect that Naledi had used the Dinaledi Cave as a repository for his remains.
Nothing discovered since then has disproved that hypothesis.
On the contrary, accumulated evidence has ruled out several competing hypotheses.
However, intentional disposal of a body is very different from burial.
(…) Therefore, to bury a person means not only to understand the concept of death being eternal, which is largely a concept originating only in the human mind, but also to have taught and learned the rituals related to burial procedures.

--- p.108, Chapter 9.
From "The Store's Clue"

I hurried to the burial site and took a look.
Photographs and maps can never capture the clarity of seeing these tombs in person.
You could see where Naledi had actually moved the dirt, how the edges were uneven, and how he had moved the mounds and then put them back in place.
Naledi had dug an oval pit, apparently larger than the body, and filled part of it with disturbed soil.
I examined the bones, each clearly identified as a part of the body, and imagined how the skeleton might have collapsed as the body decomposed in the tomb.
(…) It was a miracle that all these bones had survived for over 200,000 years and still exist today.
--- p.207~208, 「Chapter 17.
Among "More Covers"

Suddenly another implication occurred to me.
One remnant of the idea of ​​the march of progress was the notion that only later hominins used fire.
Archaeologists are confident that this hypothesis will help them determine what kind of fire was used in ancient times.
Considering the evidence of fire use that has been discovered between 2 million and 500,000 years ago, they estimate that Homo erectus was the first species to use fire.
Neanderthals and modern humans who appeared later adopted fire used by erectus and developed more complex uses such as heat-processing tools.
Evidence for the widespread use of fire appears only within the last 300,000 years.
No one would have expected that during this period there would be other types of paper used to make fire.
If fire and Homo naledi could be linked, this generally accepted timeline would undoubtedly be greatly contested.
--- p.237~238, 「Chapter 20.
From "Scorched Bones"

We've always viewed places like the Rising Star Cave and the Dinaledi Cave as unrelated places, places where we'd find entirely different pieces to complete the Naledi story.
But the Rising Star Cave's hearth taught us that the entire cave system, all its spaces, must be studied together to determine whether and how they are connected.
The answers behind this study will go beyond just painting a more complete picture of Naledi.
The development of the Naledi culture may provide a key to solving the mystery of how our ancestors, the hominins who existed before Homo sapiens, ultimately became humans.

--- p.249~250, 「Chapter 21.
From "In Search of Traces of Culture"