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The stakes are high: no less than nailing down the origins of humanity. Kermit Pattison’s Fossil Men charts the exploits of the paleoanthropological “dream team�� that discovered and explained “Ardi,�� the 4.4-million-year-old Ethiopian fossil skeleton of Ardipithecus ramidus that revolutionized how we think about the evolution of Homo sapiens.

“Lucy�� was a big deal when I was growing up. Named after the Beatles�� “Lucy in the Sky with Diamonds,�� which was playing repeatedly in the excavation camp where she was discovered in 1974, Lucy is a 40% complete fossil skeleton of an early human ancestor named Australopithecus afarensis, dating from ~3.2 million years ago. Her pelvis, which proved that hominids were walking upright in Africa at the time, destroyed the then-prevailing view that while our primitive origins were from Africa, we became “human�� later in Europe. As important, Lucy proved, among other things, that our ancestors began walking upright long before the substantial increase in brain-size that took place in hominids over the last 3 million years.

Ardi was discovered by UC Berkeley’s Tim White and his team in the Middle Awash area of Ethiopia in 1994. Ardi is a much more complete fossil skeleton than Lucy, and much older: Ardi dates from ~4.4 to 4.2 million years ago. Pattison brings to life the story of White’s painstaking research to select the best location for his team of PhDs to search for fossils during the 1993 season and the happy irony that it was Gadi, a wild local tribal enforcer who’d held White’s team at gunpoint the season before but quickly became White’s friend, constant companion and bodyguard, who first noticed a piece of Ardi (a molar) in the desert scrub. Pattison also describes the geological and climate variables that account for good fossil-hunting sites and preservation in a way that doesn’t require a science degree to quickly understand.

Pattison also paints a vivid picture of the hardships and danger inherent in fossil-hunting in eastern Africa, with the yearly dry season forays into the desert routinely beset by heat, snakes, civil war, tribal skirmishes, scientific and academic rivalries, tenuous funding, and the political black box of the Ethiopian government’s permitting bureaucracy.

Pattison clearly spent a lot of time with White, and it paid off. I felt like I was living White’s discovery and its challenges. That White was obviously involved with the book is comforting, too, because the evolution of humanity is a touchy subject the re-telling of which often seems swayed by bias. It did not take long to figure out that White was not the type to allow a bastardization of the fossil evidence for the purpose of selling books.

Pattison also draws from a wealth of sources (the endnotes and bibliography are 90 pages), including numerous Ethiopians in-country and abroad. That’s important to get a sense of what all White achieved: at the same time he was about to revolutionize current thinking on hominid evolution, White was also destroying the Great White Hunter stereotype of fossil-hunting teams epitomized by the Leakeys: White hired and trained dozens of Ethiopians to assist his work, not just as fossil hunters, guides and security, but as skilled restorers and scientists. He’s responsible in large part for training many of the Ethiopian scientists who’ve developed the National Archeological Museum in Addis Ababa into a world-class research museum.

The discovery of Ardi was of such consequence that other than a brief announcement in 1994, White kept the Ardi skeleton under wraps for an incredible 15 years (critics called it the “archeological Manhattan Project��) while he and his team sought to understand where Ardi fit in the evolutionary history of humans. Pattison does a great job of capturing the ongoing angst of the scientific community and their criticisms of White as they awaited the publishing of the results, and, on the flip side, White’s struggle to fend off those demanding he publish his findings prematurely while he painstakingly restored the fossils and set about on a worldwide, multidisciplinary research project to place Ardi in evolutionary context.

The scientific community’s expectation at the time was that the further back in time we trace our evolutionary history, the more chimp-like our ancestors would appear. The expectation was that the three evolutionary plateaus corresponding to the three genera of human ancestors, Ardipithecus (Ardi), Australopithecus (Lucy), and Homo would show a smooth transition from a chimp-like ancestor to modern humans.

Ardi shattered those preconceptions. She showed no signs of knuckle-walking like chimps and modern apes, and, to White’s and the world’s astonishment, was bipedal (which we learned from her legs, feet, pelvis and hands) but with a grasping toe, signifying she walked upright but spent significant time in the trees. After 15 years of study, White and his team postulated that Miocene (the epoch 23 million to 5.3 million years ago) apes offer a better starting point for tracing human evolution than do chimps and modern apes. That is, while our last common ancestor with chimps existed ~10 to 6.5 million years ago, modern apes (including chimps) substantially evolved during the Pliocene era (5.3 to 2.6 million years ago) into the specialized creatures they are today after their common ancestors with humans.

The scientific community was aghast at White’s theory, mostly, Pattison suggests, because many of the big names in paleoanthropology at the time were intellectually (and academically) invested in man’s descent from chimps. White was harangued, but his team held firm: “The expectations of getting more chimp-like as we go back, we never should have had them in the first place.�� White and his team took the long view. Pattison notes that the great German physicist Max Planck once observed: “New scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.�� White’s close companion Owen Lovejoy put it more succinctly: “Science progresses at the death of each faculty member.��

Another overarching lesson from Ardi, Pattison emphasizes, is that “our ancestors, even arboreal ones, do not easily fit in trees.�� Pattison concludes that “simplistic narratives contrived to fill the gaps of the fossil record often turn out to be wrong.�� Instead, the evidence shows that our family tree is more like a family bush, with substantial hybridization among the hominid species as they evolved. Pattison paints White as a skeptic who’ll follow the evidence where it takes him, but no farther. Consistent with that, White would prefer that the next generation of the profession spend more time seeking actual evidence in the field rather than conducting paleoanthropology by social media and endless, circular computer modeling. For he and his team, there is no substitute for what you can learn from the bones of our ancestors.

If I have one criticism of the book, it’s that it jumps around enough temporally that I sometimes couldn’t immediately understand whether the science Pattison was describing at the time was circa 1994 (at the discovery of Ardi), 2009 (at publication of the Ardi research), or 2020 (at publication of the book). As a result, I found myself periodically wandering off to Google to check that I wasn’t internalizing as the current understanding of some issue an idea that had since been seriously questioned or discarded.

As you might expect, White’s conclusions are still the subject of hot debate, 27 years after Ardi’s discovery and 12 years after the mountain of research his team published in 2009. One thing became clear as I read this book: there’s no telling what old bones are lying in a museum or lab at the moment, under investigation, and waiting to confirm or deny our current thinking about where we came from. This book was a nice window both into our history and how we study it. I recommend it.