Reflections

More Shaggy Cousins
by Robert Silverberg

I continue to be fascinated by the idea that human beings who were not members of the species Homo sapiens, but can properly be regarded nevertheless as human, actually walked the earth at the same time as our ancestors. It has been the subject of several of these columns over the years. Up till now they have mainly discussed Neanderthal man, about whom we are learning more and more and whose resemblance to our species gets ever closer, though with some differences significant enough to require a separate species identity. The very primitive Homo erectus (which used to be called Pithecanthropus) and the massive Homo heidelbergensis (known only from the sketchiest of fossil evidence) lived and died out, so far as we know, long before the first Homo sapiens evolved. But Homo neanderthalensis shared the world with us until quite recent times, and there is increasing evidence of interbreeding between the two human species. In fact, recent genetic studies show that we have one or two percent of Neanderthal DNA in our genomes. We can regard them as our shaggy cousins, more closely related to us than once was thought.

And now comes news of another member of our genus who was not a member of our species–a very strange one indeed, who quite probably co-existed with the earliest members of Homo sapiens. (The first beings who can be regarded as Homo sapiens are thought to have evolved in Africa about 300,000 years ago. This new fossil hominid’s remains have been dated to the period between 335,000 and 243,000 years ago, which allows plenty of room for overlap between the two species.) It has been given the name of Homo naledi, a name derived from the word meaning “star” in Sesotho, an indigenous South African language. (Like so many early hominids, Homo naledi’s fossil remains have been unearthed in South Africa. Rising Star Cave, some twenty-five miles east of Johannesburg, yielded 1800 bones of this mysterious species, representing the remains of about two dozen individuals, in excavations beginning in 2013.)

Homo naledi was a rather small creature, five feet tall at most and weighing about a hundred pounds, with long arms, curved fingers, feet, and teeth very much like ours, and–the big difference—a skull only about a third the size of ours, which would have contained a brain the size of an orange. The skeletal evidence indicates that Homo naledi walked upright, as we do and Neanderthal man did. So it would be plausible to regard him as an extinct primate, a species of ape, somewhat more advanced, evolutionarily speaking, than today’s chimpanzees and gorillas, but, having such a small brain, hardly to be considered human.

But–but–

The evidence from Rising Star Cave shows some very unusual features, features that can’t really be associated with any sort of ape living or extinct. The presence of bones of so many different individuals in a single place is a huge cultural marker, indicating that Homo naledi appears to have shown some concern for the dead, bringing bodies together in what we can readily assume must have been a kind of sacred place. Chimps and gorillas do not have graveyards. Maintaining a special place for the dead–and that is what such a site surely seems to have been–is a specifically human trait, and the oldest known graves, before the Homo naledi discovery, can be dated back only about seventy-eight thousand years. They are associated only with Homo sapiens, not with any other species of prehistoric man. Nor does it seem as though the Homo naledi bodies were simply dumped in the cave. Several of them were found lying in oval depressions, surrounded by layers of orange mud that was neatly deposited in a way that suggests careful burial.

But there is more, much more, which makes these humanoid creatures with such tiny brains all the more perplexing. They needed to have the use of fire–torches—in order to penetrate the depths of Rising Star Cave, and there are clear signs that they did. (And the caves contain the charred bones of several sorts of animals, indicating that the Naledi people either enjoyed feasts at their funeral events or made sacrificial burnt offerings to the dead, or even–who knows?–to their gods.) Not only did they bury their dead in caves, they seem to have decorated the gravesites with crosshatch markings on the walls, some executed with charcoal and some carved into the stone. It is only recently that paleoanthropologists have determined that the Neanderthals, whose brains were actually larger than ours, practiced any sort of art. Yet here are beings with brains the size of oranges at work, at least a quarter of a million years ago, at what can readily be interpreted as funereal decorations!

“This is the Star Trek moment,” said Lee Berger, a paleoanthropologist at the University of Witwatersrand in Johannesburg who has been in charge of the Rising Star excavation. “You go out, you meet a species, it’s not human, but it’s equally complex to humans. What do you do? That’s our moment, right now.”

Not human, exactly–just a small anthropoid creature with a tiny brain–but doing such remarkably human things as burying its dead and marking the site with engraved decorations. It is a cause for wonderment. Living side by side with the earliest members of our own species, here are beings quite different in form carrying out activities that we regard as typical of our own kind–beings who can be regarded, essentially, as aliens sharing our planet with us, representing a parallel line of hominid evolution. It was one that split off from the parent stock several million years ago, pursued its own course alongside our ancestors down through the millennia, and ultimately failed to survive as bigger and bigger-brained us went on to spread throughout the entire planet and culminate in a world of automobiles, computers, and space satellites. What the Homo naledi fossils show us is that brains the size of ours were not necessarily essential to developing the rudiments of civilization, and, had they somehow survived instead of us, the world today might be populated wholly by a very different civilization made up of small, elegant people with brains the size of oranges.

It’s an interestingly challenging idea. As Ernest Hemingway said in a very different context at the end of his novel The Sun Also Rises, “Isn’t it pretty to think so?”

Of course, not every paleoanthropologist does think so. The Naledi finds have been met with skepticism in various scientific quarters. One archaeologist, Joao Zilhao of the University of Barcelona, has raised the possibility that the markings on the cave walls were done by modern humans many thousands of years after the time of Homo naledi. “The whole thing is unconvincing, to say the least,” Dr. Zilhao said, and that is something that can’t be settled until samples of the charcoal used to make the markings can undergo scientific testing–which is still some time away. Another skeptical archaeologist, Dr. Paul Pettitt of England’s Durham University, casts doubt on the idea that Rising Star Cave is an actual grave site. The bodies, he says, might simply have washed in from outside. Again, that’s something difficult to disprove, although it does seem unlikely, to me, at least, that a couple of dozen bodies could have been washed by some prehistoric storm deep into such a convoluted cave. Also, the presence of the neat deposits of orange mud carefully arranged about several of the bodies does argue in favor of some sort of burial ritual. Nor does it appear probable, at least to me, that two dozen bodies accidentally wound up deep within that cave, whose labyrinthine passageways are so narrow and intricate that Dr. Berger had to lose fifty-eight pounds before he could squeeze through them. (And even at that he had some frightening moments trying to get out again.) A cautious word, too, comes from Dr. Maria Martinon-Torres of a Spanish institution, the National Research Center on Human Evolution, who, although she finds the notion that these ancient people might have been practicing some sort of burial ritual “stunning,” calls the idea that Homo naledi actually had the high degree of intelligence needed to perform the complex tasks in evidence at Rising Star Cave a premature speculation. “I don’t see an anatomical connection, I don’t see a hole or a pit that has been intentionally dug. Hypotheses need to be built on what we have, not on what we guess,” she has said.

True enough. The scientific method requires testing, verification, further testing, further verification. I have no quarrel with that. I am not a True Believer eager to accept the wildest ideas about flying saucers, alien abductions, prehistoric monsters surviving in modern lakes, and the like. Test, verify, test again: yes, by all means. We are just in the early stages of understanding the implications of the Rising Star finds.

But I am prejudiced, in a certain sense, in favor of the extraordinary and imaginative kind of scientific development. My business is speculation, not science, and though I don’t accept everything of this sort of startling nature as a matter of course, as of now I’m on the side of those who think that little Homo naledi, that tiny-brained ape-like creature who lived so long ago, actually did have the use of fire and went to great lengths to bury its dead, with appropriate rituals, in that almost inaccessible cave, after which the walls of the cave were decorated with markings and carvings that meant something significant–what, we will never know–to the people who did them.

What the discovery of Homo naledi teaches us, if the findings of Dr. Berger and others ultimately stand up to scientific testing, is something rather humbling: that big brains are not necessarily a key to the ability to carry out complex ideation. So we hear from Dr. Dietrich Stout, a neuroscientist at Emory University who is not a part of the Rising Star research:

“I think the interesting question moving forward is what exactly big brains are needed for,” says Dr. Stout.

My brain is considerably bigger than that of Homo naledi, and so is yours. I wrote this column with brain-and-finger coordination, using an Apple iMac computer, and not even the brightest of Homo naledi could have done that, nor could any of them read what I have written. Even so, I’d like to believe that these little anthropoid creatures of a quarter of a million years ago were every bit as smart as our primordial ancestors, and would eventually have gone on to iMacs or something even better if they had not died out, all those vast millennia ago. It’s an astonishing idea, more science fiction than science at the moment. Unlike the idea that Homo naledi buried its dead and put ceremonial decorations on the walls of that cave, which can in the course of time be validated by further research, that isn’t subject to any sort of proof. It’s just the speculative notion of a science fiction writer who has earned his living, over the years, by playing with all sorts of imaginative possibilities. I do indeed want to believe that there was, in Africa long ago, a two-legged primate that, despite having what we loftily consider a tiny brain, was capable of a notable degree of abstract thought. Which, I suppose, puts me squarely on the side of Lee Berger and Ernest Hemingway: “Isn’t it pretty to think so.”

Copyright © 2024 Robert Silverberg