‘Story of human origin is still not figured out or over’

In fact, on the day Lucy was found —Sunday, November 24, 1974—Ethiopians woke up to some other devastating news. The previous night, Ethiopia’s military regime had executed more than 60 ministers and generals of Emperor Haile-Selassie’s regime. The announcement of Lucy’s discovery probably came up later that week, but I doubt many people paid attention to it amid all the turmoil, with the military regime taking control of Ethiopia.

Personally, I have no recollection of the announcement of Lucy’s discovery. I grew up in a Christian family, so as far as I knew at that time, it was God who created humans and I wouldn’t have understood the significance of Lucy.

Of course, over time, her discovery brought the idea of Ethiopia as a “cradle of mankind” to the forefront of public consciousness around the world. With that came national pride—today, Ethiopia brands itself the “land of origins”. Lucy played a big part in that.

Many of the fossils that made western scientists famous were actually found by local Africans, who were only acknowledged at the end of a scientific publication. For a long time, African scholars were never part of telling the human story; nor could they actively participate in the analysis of the fossils they found. Up to the 1990s, long after Lucy was found, we were only present in the form of labourers and fossil hunters.

So, when we celebrate the 50th anniversary of Lucy, we shouldn’t forget that a reappraisal of the role of African scientists in our understanding of ancient humans is long overdue. Specifically, we need to decolonise paleoanthropology.

Without the proper infrastructure, African countries are going to be stuck in the same old cycle where they are expected to facilitate western scientists’ research—with institutions getting some income from laboratory service fees, and some locals being paid field per diems, but that’s about it. If you ask anyone who works in Kenya, Tanzania, Ethiopia or South Africa, they will tell you things have to change, particularly in terms of local scholar training and involvement in the actual research. That’s why this movement of decolonising palaeontology is becoming really vibrant now. We need a firm foundation established, so the next generation of African scientists doesn’t have to deal with issues, like lack of infrastructure, that we faced. This requires a change in terms of how we think about paleoanthropology—and how we think about Africa in general. African institutions don’t have the resources or trained manpower to develop programmes like this—and most African countries have a lot of pressing social, political and economic concerns, so paleoanthropology is not going to be their highest priority. But, if they are interested in seeing more of their scholars involved in this field, they need to build the necessary infrastructure so that foreign researchers can help with programming and training. Scientists cannot build laboratories, but they can help with what goes to those laboratories and help develop training programs.

I’ve found so many important fossils in the Middle Awash [a key research area in the Afar region] that I can’t exactly say one is more important than the other. But the first one that really made an impact was “Ardi” (from the full species name Ardipithecus ramidus) in 1994, which I found when I was still a graduate student at the University of California at Berkeley. Just as Lucy resulted in a major paradigm shift 50 years ago, Ardi again transformed the way we think about human origins.

The first piece I spotted was a finger bone, but in time we found Ardi’s near-complete skeleton. Another female, she had complete hands, feet and more skull bones that were missing from Lucy. She was dated at 4.4 million years old—1.2 million years older than Lucy, and an entirely new genus of a hominin, Ardipithecus, that looked unlike anything that had been found before.

Once you get used to finding good fossils, you don’t tend to get as excited when you find another. But there’s one discovery I will never forget—the extraordinary feeling when I found the partial jaw of Ardipithecus kadabba in December 1997, a species I went on to name four years later.

Part of the jaw was just lying there on the surface. And deep inside, something immediately told me I had found the earliest human ancestor—more than 5 million years old. The thought made me go numb for a few seconds—I’ve never had that kind of feeling again. Literally no hominin fossils from that age had ever been discovered before.

The first thing I did was stand up and look 360 degrees around me, to check I wasn’t at one of the other, younger geological parts of the Middle Awash. My Ethiopian compatriot, Giday WoldeGabriel, and I had been surveying this new area for a few years. I was still looking for a topic for my dissertation—my advisor had told me: “Go look for fossils in the older deposits [more than 5 million years old], find as many as you can, and describe them.”

I’m trained as an osteology student, so I can easily distinguish fragments of an ancient human skeleton from other fossils. And the jaw still had one tooth on it—so it was really easy for me to identify. After that, we surface-scraped and found a lot more teeth from the same jaw. Everybody was so excited.

It’s a desert area, so the water resource has always been limited. There’s one river that flows all year round, and it’s the only water we all have access to. But climate change is resulting in less grass for the animals to graze on, so the people we work with sometimes move farther away from their usual area looking for grazing land—and sometimes that gets them into conflict with other clans. Some years, we don’t see a good number of our usual workers because they went somewhere else with their animals. This is nothing new—it’s been happening for many, many centuries. But climate change is altering a lot of things on the landscape, and increasing the risk of deadly conflicts as different clans try to access limited resources.

The Afar desert in Ethiopia was not a desert in the deep past. It was a place where life, including some of our earliest ancestors, flourished for millions of years. But the fact this area is located in a tectonically active region with three of Earth’s plates slowly pulling apart, creating a deep rift valley between them – the rifting has facilitated the past life history of the area to resurface in the form of fossils. In that sense, the region is geologically unique and not seen anywhere else in the world.

So, we cannot conclusively say these early human ancestors whose fossils we are finding in the East African Rift valley never lived anywhere else. The problem is we don’t have, or haven’t yet found, many ancient sediments of equivalent age outside eastern Africa where we can look for fossils of ancient human ancestors.

There are some very important exposed sediments outside the East African Rift system—for example in Chad in Central Africa, where the very earliest hominin fossils have been found, dating back between 6 and 7 million years. But a much wider geographic distribution of early human ancestors, at least within the tropics, cannot be ruled out. That is why continued survey and exploration outside the known sites in East and South Africa is of paramount importance.

We’ve collected hundreds if not thousands of early human ancestors over the last 50 years since Lucy was discovered. When she was found in 1974, all we could study was what was visible on the external surface of her bones—taking measurements and so on. But now, we have the technology to scan her skeleton and look at the internal structure of the bones.

So, even if we don’t have any new fossils emerging, those we already have in our museums and laboratories will keep generating a lot of knowledge because we’re improving the technology; the way we analyse the fossils.

(The interview is republished from The Conversation)

This was first published in the 1-15 January, 2025 Print edition of Down To Earth