Back in 2014, I took a challenging but rewarding MOOC (Massive Open Online Course), “Human Evolution: Past and Future,” a free online course taught by University of
Berger, who frequently partners with National Geographic, has in common with Hawks an absolute devotion to open access, which has made him unpopular among some of his more traditional peers. Berger and Hawks passionately believe that—especially given today’s technology and speeds of communication, as well as tendencies towards ever increasing specialization—that such free and open access is essential to fostering advances in all of the related fields. This passion also extends to the general audience, as evidenced in Almost Human: The Astonishing Tale of Homo naledi and the Discovery that Changed Our Human Story, by Lee Berger and John Hawks, a well-written, fast-paced narrative that puts a focus to the latest finds and the cutting-edge technology and techniques of paleoanthropology.
My training is as a historian rather than a paleontologist, but I have been fascinated by fossil finds ever since I was a boy, when I followed the adventures of the Leakey’s in National Geographic, and later bought books by Richard Leakey and Donald Johanson that sit on my shelves to this day. The discovery of the magnificent 3.2-million-year-old Australopithecus afarensis nicknamed “Lucy” was a big deal for this teenager! So, I have to confess to some delight when Berger reveals in the opening chapters that as a youth, on his somewhat circuitous route to paleoanthropology, he thrilled to these very same volumes. Back in those days, it was once remarked that our entire collection of hominin fossils could be displayed on a single large table. As Berger and Hawks remind us in Almost Human, those days are long past!
This is a very exciting time for studies in human evolution, both because of a plethora of new fossil discoveries, as well as stunning advances in technology that permit a far more detailed knowledge of the lifeways of our early hominin antecedents. For instance, we can now determine with some certainty, based upon carbon isotopes retrieved from fossil teeth, what the owners of those teeth once dined upon. And rather than the familiar “tree of evolution” found in early textbooks, we now know that the model is far “bushier,” with many descendants of a distant common ancestor that turned into dead ends. Modern humans, Homo sapiens sapiens, are the only surviving species of the genus Homo, but paleoanthropology has revealed that we have many extinct relatives, and we will likely stumble upon many more. In addition to Lucy, there were several other australopithecines, which are not in our direct line of descent, as well as a number of Homo varieties, including the recent surprising and controversial discovery of Homo floresiensis, nicknamed the “Hobbit,” a kind of dwarf hominin that inhabited the Indonesian island of Flores. Far less ancient Denisovans have been found in Asia that are, like Neanderthals, archaic humans. Clearly there is no straight line from our ancestors to us.
Perhaps nothing underscores that more than the two astonishing discoveries directed by Lee Berger. The first, the nearly two-million-year-old fossils of Australopithecus sediba, was actually found not by Berger but by his nine-year-old son in 2008. What is remarkable about sediba is that despite its antiquity, it sports surprisingly modern hands and quite humanlike ankles, yet also—significantly—retains the more ape-like attributes often characteristic to an australopithecine. Such a weird amalgam of features both ancient and more recent are termed “mosaics” by paleontologists, and there was probably no greater example of this than sediba.
At least, that is, until Berger had a look at the fossils of what was later to be called Homo naledi, first discovered in 2013 by recreational cavers exploring the Rising Star cave system, in the vicinity of Johannesburg. Homo naledi, a mere 300,000 years old, nevertheless demonstrated mosaic features far more archaic than would be expected from a hominin significantly younger than other specimens of Homo known for larger brains and more modern characteristics. At the same time, there were also distinct anatomical features that clearly identified it as part of the Homo lineage. What those cavers had stumbled upon, at the end of a narrow chute, was the long-isolated Dinaledi Chamber, littered with fossils that turned out to represent more than a dozen naledi individuals. This extraordinary discovery was the foundation of Berger’s Rising Star Cave Expedition that is the central focus of Almost Human.
The Rising Star Cave Expedition, which included Hawks and a truly remarkable team, was presented with a unique set of excavation challenges. The 650 foot (200 meter) labyrinthine route to the Dinaledi Chamber included a particularly claustrophobic segment tagged as “Superman’s Crawl,” a short tunnel less than 10 inches (25 centimeters) wide, so-called because traversing it requires a bodily contortion with one arm stretched above your head and the other held tight against your body, like Superman flying. This was followed by a vertical climb of some 65 feet (20 meters) up an underground ridge called Dragon’s Back, and then a perilous descent through a 39 foot (12 meter) vertical chute that narrows at one point to only some 7 inches (18 centimeters) wide! Berger brilliantly overcame this daunting hurdle by recruiting the most qualified paleoanthropologists, with climbing and caving experience, who were also physically of the smallest stature, and therefore best suited to probing the narrowest passages. The six who were selected, all women as it turned out, were nicknamed the “Underground Astronauts.”
The story of these intrepid explorers makes for an exciting tale that is sometimes related breathlessly, yet never sinks to pulp. While it is eminently clear that this expedition is underway in the first part of the twenty-first century—replete with state-of-the-art technology and communication—there remains an ever-present palpable element of old-fashioned danger as flesh-and-blood scientists slowly and painstakingly navigate Superman’s Crawl, and then later descend that very narrow chute, to retrieve those precious bones that have lain undisturbed for several hundred thousand years. The narrative is so well-written that the reader can almost hear Berger’s heart thumping in his chest as he monitors the steady progress of his Underground Astronauts, ever alert that there are indeed things that can go very wrong in this extreme environment that could mean injury or death for them.
I must admit just a hint of disappointment with Almost Human at first, for while it is hardly dumbed-down, I had hoped for a bit more emphasis on the fossil morphology, and perhaps a more technical examination of how naledi fit with the rest of the evolutionary bush. But that quickly passed. This is not that kind of book. Instead, Almost Human is an adventure story of discovery in a field that these days is all about breaking news, told by two men with the talent to articulate it. And Berger’s commitment to open access means that the news of such discoveries is actually getting out, at least in his arena, rather than remaining squirreled away for years as had long been standard practice. Homo naledi and the progress of the Rising Star Expedition has been the stuff of social media for several years now; I learned of the publication of Almost Human on Twitter.
Race, we now know, is a meaningless construct: all living humans today are more closely related to each other genetically than the two chimpanzee populations of west and east Africa are to one another. But it was not always that way. The search for human origins is a complex one, and new discoveries and interpretations ever alter the contours of the twigs on that bush. It is a fascinating story, but much of it is often given to the secrecy and arcane jargon of science and academia, and thus lost to a wider audience. Almost Human is a welcome respite from that, and I highly recommend joining Berger and Hawks and their Underground Astronauts on this fascinating journey to resurrect a piece of our past and proudly show it off to the world.