Fossil Finders: Kamoya Kimeu

Fossil Finders is a series devoted to telling the stories of the people behind important fossil discoveries. In this first installment, Leakey Foundation Fellow Carol Broderick brings us the story of the legendary Kamoya Kimeu.

Kamoya Kimeu (right), partner of Richard Leakey (left) for two decades, turns up facial bones of a fossil Homo erectus under a thorn tree on the western shore of Kenya’s Lake Turkana. Photo by David L. Brill 1985, National Geographic Society, From The Leakey Foundation Archive

By Carol Broderick

Most paleontologists track their careers in terms of funding and expedition cycles, searching for fossils in finite windows of time and often spending months, even years waiting to return to promising sites. It is rare that someone is able to devote his or her life to searching for fossils, yet one man has done exactly that. That man is Kamoya Kimeu.

Kamoya Kimeu was 21 years old when he was approached by Louis Leakey to join his expedition as a field worker at Olduvai in 1960. Originally, he thought Leakey’s job description, which included “digging for bones,” entailed grave digging. “We didn’t know then about hominid bones, that there were such things. I thought we were coming to dig some graves of dead people,” Kimeu recalled. In his Kamba tribe, touching the dead, as in many tribes, was considered a serious violation. Yet Leakey, who enthusiastically explained the work to be done in fluent Kikuyu, won Kimeu’s trust. “I could see that this mzunga was not like the others; he was talking to us like a person.” And this was the beginning of Kamoya Kimeu’s legendary fossil hunting career.

When Mary Leakey became “Director of Excavations” at Olduvai, she decided to hire all Kamba workers instead of the Kikuyu workers Louis had used. Kimeu, who is Kamba, continued to work for Louis and Mary Leakey and then Richard and Meave Leakey for the next two decades. His knowledge of Kikuyu, Swahili, and English was instrumental in working with both staff and the other researchers. In 1977, Kameu became curator of prehistoric sites for the National Museums of Kenya; he also continued to work with the Leakeys in the field.

View of Olduvai Gorge, one of the most important paleoanthropological sites in the world. Great Rift Valley, Tanzania, Eastern Africa.

How did this man, the son of a goat herder, go on to become what some paleontologists believe is the greatest fossil finder of all time?

When Mary Leakey chose the Kamba tribe as her staff, she did so because she had seen the intricate chains and wood carvings they made. She felt that members of the tribe had the potential to master skills to do difficult work that required diligence and patience, carefulness and attentiveness. Kamoya Kimeu embodied these traits as he set his sights on the mandibles and skulls of our ancestors. As a boy living in the bush, Kimeu had to learn survival skills, to find water and food for the animals, and to read the land. This knowledge of the East African landscape proved to be invaluable in the field.

Kimeu also learned his skills from the best paleontologists in the field at that time. Louis Leakey taught him about evolution and paleontology. Mary Leakey taught him excavation techniques which are still valued by researchers in the field. Richard Leakey, too, passed on his attention to detail. Before Richard became a renowned paleontologist, Kimeu worked with him in an animal skeleton business. Each bone was carefully labeled, and Kimeu soon was able to distinguish one animal from another. All of this education enabled him to be a master of his trade.

Richard Leakey remarked on Kimeu’s incredible talent at finding fossils from everything from elephants to australopithecines: “To some of our visitors who are inexperienced in fossil-hunting, there is something almost magical in the way Kamoya or one of his team can walk up a slope that is apparently littered with nothing more than pebbles and pick up a small fragment of black, fossilized bone, announcing that it is, say, part of the upper forelimb of an antelope. It is not magic, but an invaluable accumulation of skill and knowledge.”

Kimeu also has his own theory concerning his incredible discoveries. In an article published in National Geographic, he said that he actually speaks to our ancestors in an imaginary language, Kikoshwa, and they tell him where to find the fossils! But perhaps the most logical answer lies in the fact that he spent so many days, so many years in the field. As the article’s author wrote, this “irrepressible energy” and the fact that Kimeu rarely took time off from his excavating, undoubtedly increased his chances of finding fossils.

Kimeu’s discoveries have not only been numerous; they have also been incredibly important to the study of paleoanthropology. It is impossible to list all of the fossils Kamoya himself has found. His fellow fossil finders, members of Kimeu’s “Hominid Gang,” also made their own discoveries, which will be part of a future “Fossil Finders” series article.

Here are a few of Kamoya Kimeu’s most important discoveries:

  • In January of 1964 at the Peninj site near Lake Natron in Tanzania, Kimeu, working with Richard Leakey and Glynn Isaac, found an entire mandible of a Paranthropus boisei (later identified as an Australopithecus boisei ) known as the Peninj Mandible. This find was particularly important to Louis Leakey, who thought that this robust form of hominid was not ancestral to Homo; Louis believed this discovery confirmed that assumption. At approximately two million years old, this hominid would have been a contemporary of Homo habilis and not its direct ancestor as some scientists had proposed.
  • In 1968, again on an expedition with Richard in the Omo valley of Ethiopia, Kimeu discovered an early Homo sapiens skull. This discovery was instrumental because until then, no one believed Homo sapiens could be this old. Dated at 130,000 years old, until this discovery, many anthropologists believed that Homo sapiens had not appeared until after the Neanderthals, or approximately 60,000 years ago at the latest. This discovery also proved that Neanderthals and Homo sapiens were contemporaries, an important piece of the complex human story.
  • Kimeu worked with Richard, again, in the late 60’s at Allia Bay in Lake Turkana. They endured extremely difficult conditions: dangerous heat (105-110 degrees) and blistering wind, excavating over twenty miles per day because of the huge number of fossils. It was at Allia Bay that Kimeu found two teeth of Australopithecus africanus. On the same trip, at Ileret River in Northern Kenya, Kimeu found part of another Australopithecus jawbone, important because the Omo deposits were approximately 150,000 years old or perhaps even younger while the Lake Turkana deposits were dated at 1-4 million years old.
  • By 1973, research at Koobi Fora was ongoing; however, Richard Leakey, who was busy running several museums in Nairobi, rarely searched for fossils himself. Kimeu’s team managed to find more than twenty hominid fossils that season. It was here that Kamoya Kimeu located a new fossil, KNM-ER 1813, a Homo specimen with a relatively small braincase. This gracile hominid resembled the Australopithecus africanus discoveries of South Africa. Its significance was that it indicated that at least one Homo group and both kinds of Australopithecines’s lived between one and three million years ago. It was dated between 1.8-1.9 MYO, but this date was not without controversy. Richard believed that it was the fossil of Homo habilis, but this, too, was also hotly debated.
  • Probably Kimeu’s most famous fossil discovery was that of an almost complete Homo erectus skeleton labeled KNM-WT 15000 but known in paleoanthropological circles as Turkana or Nariokotome boy. Found in 1984 at Kenya’s Lake Turkana where Richard Leakey and Alan Walker were doing research, it was described as a young male between 9 and 11 years old and dated at approximately 1.6- 1.5 million years old. The sequence of events of this discovery was by that time a familiar one. While walking next to a slope of black rocks next to the dry Nariokotome River, Kimeu noticed a dark bit of bone. “How he found it, “Walker wrote, “I’ll never know.” Kimeu radio phoned Richard about his discovery, their usual mode of communication, suggesting that it might be part of a Homo erectus skull. Richard arrived quickly, confirming Kimeu’s classification and marveling at what would become the first skeleton of a Homo erectus and the most complete skeleton since Lucy! Some paleontologists classified the remains as Homo ergaster, but today it is considered to be an example of Homo erectus.
  • In 1985 Kimeu found a partial skull of a new hominoid about 60 miles from Nariokotome. It possessed a particularly long muzzle and appeared very different from all previous hominoid/ape discoveries. Richard and Meave named it Turkanopithecus kalakolensis.
  • In 1994, working with Meave Leakey at Kanapoi in Southwest Turkana, Kimeu found two parts of a hominid shinbone; others found more of this fossil and it was dated at approximately four million years. It was given a new species name, Australopithecus anamensis.

This list does not include all of Kamoya Kimeu’s finds, but it shows how his discoveries were important not only to the controversial classifications proposed by the Leakeys but to the science of paleontology itself. As these finds were documented in scientific journals, it became clear that the Ph.D. next to a scientist’s name was essential in the actual excavation, naming and formal description of the fossils. East African staff were not always given recognition by those who depended on their discoveries for their scientific careers. Kamoya Kimeu was one of the first native East African fossil finders to be given this recognition.

Certainly, the Leakeys recognized his unique talents. At Richard Leakey’s camp, Kimeu sat with Richard and the other scientists at the “management table,” and by 1972, he had “assumed control of field operations” for Richard in his absence as he was busy running several museums in Kenya.

In 1985 Kimeu was awarded the National Geographic Society La Gorce Medal by Ronald Reagan at the White House. This prestigious award is for “accomplishment in geographic exploration, or in the sciences, or for public service to enhance international understanding.”
The media, too, singled out Kimeu for his contributions. National Geographic Society President Gilbert Grosvenor wrote, “Thanks to his work, our forerunners of the distant past have begun to speak not only Kikoshwa but the language of all mankind.”

There is probably no greater recognition than to have fossils named after you. Two fossil primates have been given this honor: Kamoyapithecus hamiltoni and Cercopithecoides kimeui.
Today, it is still relatively rare to find paleontologists who live in the field. Of course, Louis and Mary Leakey were examples of two people who introduced Kimeu to this life, and now Meave and Louise Leakey carry on that tradition.

In 1994 Kimeu called Meave, now head of paleontology at the National Museums of Kenya. He was at Kanapoi in Southwest Turkana. He and his Hominid Gang colleagues brought her to a site where Kimeu had found yet another piece of a  shinbone, another one of his gang an upper jaw of a hominid. Once again, the Leakeys and Kimeu were involved in unearthing another of his important discoveries. Kimeu cradled the teeth in his hands and said, ‘Surely this is where we come from,” the words of a wise man who has brought life to fossils that have changed our world and the shed light on the history of our closest ancestors.

New Discovery Updates the Story of Early Human Migration

A project led by the Max Planck Institute for the Science of Human History has discovered a fossilized finger bone of an early modern human in the Nefud Desert of Saudi Arabia, dating to approximately 90,000 years ago. The discovery, described in Nature Ecology and Evolution, is the oldest directly dated Homo sapiens fossil outside of Africa and the Levant and indicates that early dispersals into Eurasia were more expansive than previously thought.

Researchers conducting archaeological fieldwork in the Nefud Desert of Saudi Arabia have discovered a fossilized finger bone of an early member of our species, Homo sapiens. The discovery is the oldest directly dated Homo sapiens fossil outside of Africa and the immediately adjacent Levant, and indicates that early dispersals into Eurasia were more expansive than previously thought. Prior to this discovery, it was thought that early dispersals into Eurasia were unsuccessful and remained restricted to the Mediterranean forests of the Levant, on the doorstep of Africa. The finding from the Al Wusta site shows that there were both multiple dispersals out of Africa, and these spread further than previously known.

Fossil finger bone of Homo sapiens from the Al Wusta site, Saudi Arabia. Photo: Ian Cartwright

Oldest directly dated Homo sapiens fossil outside of Africa and the Levant

The results, published in Nature Ecology and Evolution, detail the discovery made at the site of Al Wusta, an ancient fresh-water lake located in what is now the hyper-arid Nefud Desert. Numerous animal fossils, including those of hippopotamus and tiny fresh water snails were found at Al Wusta, as well as abundant stone tools made by humans. Among these finds was a well preserved and small fossil, just 3.2 cm long, which was immediately recognized as a human finger bone. The bone was scanned in three dimensions and its shape compared to various other finger bones, both of recent Homo sapiens individuals and bones from other species of primates and other forms of early humans, such as Neanderthals. The results conclusively showed that the finger bone, the first ancient human fossil found in Arabia, belonged to our own species. Using a technique called uranium series dating, a laser was used to make microscopic holes in the fossil and measure the ratio between tiny traces of radioactive elements. These ratios revealed that the fossil was 88,000 years old. Other dates obtained from associated animals fossils and sediments converged to a date of approximately 90,000 years ago. Further environmental analyses also revealed the site to have been a freshwater lake in an ancient grassland environment far removed from today’s deserts.

Lead author Dr. Huw Groucutt, of the University of Oxford and the Max Planck Institute for the Science of Human History, states, “This discovery for the first time conclusively shows that early members of our species colonized an expansive region of southwest Asia and were not just restricted to the Levant. The ability of these early people to widely colonize this region casts doubt on long held views that early dispersals out of Africa were localized and unsuccessful.”

Survey and mapping of the Al Wusta site. Photo: Klint Janulis

Modern deserts of the Arabian Peninsula were once lush grasslands that humans were able to colonize

Project Lead and Leakey Foundation grantee, Michael Petraglia of the Max Planck Institute for the Science of Human History adds, “The Arabian Peninsula has long been considered to be far from the main stage of human evolution. This discovery firmly puts Arabia on the map as a key region for understanding our origins and expansion to the rest of the world. As fieldwork carries on, we continue to make remarkable discoveries in Saudi Arabia.”

The international consortium of researchers involved in this project is headed by the Max Planck Institute for the Science of Human History, in partnership with the Saudi Commission for Tourism and National Heritage. Additional partners include the Saudi Geological Survey, King Saud University, the University of Oxford and other key institutions in the United Kingdom and Australia.

Happy Birthday Leakey Foundation!

Did you know that April 8th is the anniversary of The Leakey Foundation’s first board meeting in 1968? This makes for the perfect time to launch festivities for The Leakey Foundation’s 50th anniversary!

The theme for our anniversary is Discovering Us, and we have many exciting events planned to help us celebrate the accomplishments of the past 50 years and explore the endless possibilities of the future!

The celebration is just beginning, and it won’t end until April 2019; however, we have some special events planned for this April and May that you will not want to miss!


We are kicking things off at this year’s American Association of Physical Anthropologists (AAPA) conference in Austin from April 11-14.  This year much of the foundation’s staff will be present to get this anniversary started right.

Come visit us at our table in the exhibitor hall (Ziker 1/2/3, booth 9). Get to know the foundation and our staff, register for our daily giveaway or even take a turn in our photo booth.

We will wrap up our visit to Austin with a “birthday” party at local venue Antone’s Nightclub, hosted by Leakey Foundation trustee Spencer Wells. All AAPA meeting attendees are invited to join us at Antone’s on Friday April 13th from 8 pm to closing.

The Leakey Foundation 50th Anniversary Gala

Celebrations for our 50th anniversairy would not be complete without a party! Join us on May 3, 2018, at the beautiful St. Regis hotel in San Francisco for The Leakey Foundation’s 50th Anniversary Gala. This very special evening will feature renowned scientists, gourmet dinner with wine provided by Grgich Hills Estate, music, and a reception with a hosted bar featuring sparkling wine provided by Iron Horse Vineyards.

Proceeds from this event will help fund human origins research and outreach. This event will sell out quickly. Tables, sponsorships, and individual tickets are available now! Click here to register for what promises to be an unforgettable evening!

Speaker Series: What Makes Us Human? Lessons from the Study of Wild Chimpanzees by John Mitani

Join us at the Houston Museum of Natural Science at 6:30 pm on April 17th. In this talk, John Mitani will review findings that reveal some interesting parallels between humans and chimpanzees with respect to friendships, longevity, and cooperation.  Humans form long-lasting friendships, live a very long time, and are an unusually cooperative species. Studies of the Ngogo chimpanzees indicate that the gap between them and us in these regards may be smaller than previously thought. These findings furnish new insights into chimpanzee behavior and are particularly relevant as we continue to struggle to conserve the dwindling populations of these animals. Click here for more information.

Speaker Series:  Atapuerca: Crossroads of Human Evolution in Europe by María Martinón-Torres

Join us at the California Academy of Sciences at 7 pm on May 2nd. In this talk María Martinón-Torres will discuss her work tracing the origins of our closest extinct relatives, the Neanderthals. She will also share how fossils of Homo antecessor, an early human species, found at Atapuerca have shifted our understanding of the ancestry of the first Europeans. Click here for more information.


From the Field: Julie Lesnik

Julie Lesnik was awarded a Leakey Foundation Research Grant during our fall 2015 cycle for her project entitled “An evaluation of termite-associated hydrocarbon signatures as an influence on prey selectivity and an ecological signal for chimpanzees and Olduvai hominins.” (Click here to read a summary of her project.) Her co-PIs are Clayton Magill and Robert O’Malley.

For our project, the year 2016 was focused on fieldwork while 2017 has been all about the lab.  The various elements of this project are now coming together, and we look forward to sharing our findings in 2018.  Since this project has incorporated work from several different locales, I wanted to highlight each in this recap.

In April of 2016, I traveled to the town of Thohoyandou in Limpopo, South Africa.  There I met women who forage for termites to sell in the local marketplace. The methods they used to collect the termites are more complex than that seen in chimpanzees, but the basic concept is the same: break into the mound and insert thin plant stems on which the termite soldiers will bite.  However, instead of inserting a single tool into one of the tunnels on the mound, they break open a hole and shove in a bunch of stems that form a simple brush or broom.  The increased surface area of the multiple strands means a higher yield with each dip.  The attached termites are removed from the broom by quickly running a hand down its length and stripping the termites into a bucket.  This bucket is taken home, and the termites are washed, cooked, and prepped for market.  With the help of these women, I collected two different species of Macrotermes termites (and soil samples from their mounds).  Although both species are consumed, one is strongly more preferred.

1: M. Tshisamphiri using a rudimentary broom to remove termite soldiers from their mound in Thohoyandou, South Africa

2: I was excited by the haul of termites collected for sale in Thohoyandou, South Africa.

These termites will help us determine if there are distinctive organic chemical (hydrocarbon) signatures between preferred and lesser-preferred termites, which will be compared to species for which we do not have evidence of consumption.

In June of 2016, I joined co-PI Clayton Magill at Olduvai Gorge, Tanzania.  We collected termites that are not consumed by people to act as control in our analyses.  More importantly, our time at Olduvai was spent collecting soil samples of features found within the hominin site that looked like social insect nests.

3: Insect nest feature from Olduvai Gorge, Tanzania

4: Clayton Magill mapping the stratigraphy surrounding a termite nest feature at Olduvai Gorge, Tanzania

In November of 2016, I joined co-PI Robert O’Malley at Gombe Stream National Park, Tanzania, where we collected termites and soil samples from mounds where Rob and other researchers had previously seen chimpanzees fishing for termites.  This forest and the well-habituated chimpanzees enthralled me, and I detailed my day-to-day experiences on my personal blog .

5: Robert O’Malley (left) and Jane Goodall Institute field guide Halfan collecting and recording termite samples at Gombe Stream National Park, Tanzania

6: Gombe chimpanzee, Glitter, using a tool to eat termites

The samples from all these sites were shipped to Clay’s lab at Heriot-Watt University in Edinburgh, Scotland.  His lab is part of the new Lyell Centre that opened in 2016; so it took some time to get the instruments installed and optimized to do our analyses.  We are just getting in our results and are very excited to see that the hydrocarbon signatures of the termites are distinguishable at the genus (or sometimes species) taxonomic level.  More exciting still is that the sediments from associated nests also contain these biomarkers.  Our next step is to explore the sediments we collected from Olduvai Gorge for termite biomarkers!

Many people ask us about “how” we do our molecular and isotopic analyses, so we thought that a quick tutorial might be of interest.  In essence, our analyses are initiated by extracting all of the fats (lipids) from our samples using a special instrument called an Accelerated Solvent Extraction (ASE) system (Image 7).  Once the lipids are extracted from a sample, they are chemically separated to isolate specific molecules of interest – in this case, we are looking for saturated fats and termite “sterols” (i.e., biomarkers), which are equivalent to cholesterol in humans.  Sometimes the biomarkers show vivid colors (Image 8)!   We then analyze the occurrence, abundance and distribution of different biomarkers in our samples using gas chromatography-mass spectrometry (GC-MS; Image 9).  Using a similar, although much more sensitive, instrument called GC-isotope ratio monitoring-MS (GC-irMS; Image 10) the separated biomarkers are analyzed for their respective stable carbon isotope composition (13C/12C).  This ratio is important because it allows us to distinguish termites that have grass-like (high 13C/12C) versus tree-like (low 13C/12C) carbon signatures, which is important for interpretations of their incorporation into other animal’s diets, including extinct hominins.

7: Accelerated Solvent Extraction (ASE) system used to extract lipids from our samples

8: Extracted termite biomarkers can be very colorful

9: Equipment used for gas chromatography-mass spectrometry (GC-MS)

10: GC-isotope ratio monitoring-MS (GC-irMS)

We will be presenting the results of this research at the Paleoanthropology Society meetings in April in Austin, TX.

How Infighting Turns Toxic for Chimpanzees

How did a once-unified community of chimpanzees in Gombe National Park, Tanzania, end up at each other’s throats? Tensions that divided these top males also divided their community, researchers find. Photos by Geza Teleki.

Power. Ambition. Jealousy. According to a new study, the same things that fuel deadly clashes in humans can also tear apart chimpanzees, our closest animal relatives.

In the early 1970s, primatologist Jane Goodall and colleagues studying chimpanzees in Gombe National Park, Tanzania, watched as a once-unified chimp community disintegrated into two rival factions. What followed was a period of killings and land grabs, the only civil war ever observed in wild chimpanzees.

Now, thanks to research funded in part by The Leakey Foundation using newly digitized field notes in the Jane Goodall Institute Research Center at Duke University, scientists have been able to take a closer look at the seeds of the conflict. What started as infighting among a few top males vying for status and mates is likely what eventually caused the whole group to splinter.

The study was published March 22 in the American Journal of Physical Anthropology.

The exact nature and cause of the split leading to what Goodall called the “Four-Year War” at Gombe from 1974 to 1978 has long been a mystery, said first author and Joseph Feldblum, postdoctoral associate with professor Anne Pusey at Duke. During the war, males within an area of the park known as Kasekela teamed up to raid neighboring territories, brutally beating and killing half a dozen former comrades.

Some researchers have suggested the friction was sparked by the banana feeding station Goodall used to lure chimpanzees for observation. They proposed that two distinct chimp communities may have existed all along or were already dissolving when Goodall began her research, and the feeding station merely brought them together in a temporary truce until they parted again. But new results from a team at Duke and Arizona State University suggest something more was going on.

Using data extracted from Goodall’s copious hand-written notes and checksheets, which Pusey has spent the last 25 years archiving and digitizing, the researchers analyzed the shifting alliances among 19 male chimpanzees leading up to the split.

They mapped the chimps’ social networks at different periods between 1967 and 1972 to pinpoint when relations began to fray. Two males were considered buddies if they were spotted arriving together at the feeding station more often than other pairs.

Next, the researchers identified the most tightly knit groups in each network and determined how much their members changed over time.

“We used network analysis to quantify the degree to which individuals are cliquish, essentially,” Feldblum said.

Their analyses suggest that for the first few years, from 1967 to 1970, males in the original group intermingled.

But statistical tests revealed clusters of males that grew more distinct over time. Some males spent more time in the northern part of the range. Another group increasingly withdrew to the south.

By 1971, they found the northern and southern males met less and less often. When they did encounter each other, they would hurl branches, hoot, and charge through the forest as a show of strength.

“We would hear these pant-hoot calls from the south and say to ourselves: the southern males are coming! All the northern ones would go up trees, and there’d be a lot of screaming and displaying,” said Pusey, who observed them firsthand as a doctoral student at Gombe from 1970 to 1975.

Within a year, the cliques began to harden and became increasingly exclusive, results show.

Where once the chimps groomed and spent time with other males both inside and outside their subgroup, by 1972 they socialized almost exclusively with males on the inside, with minimal range overlap between northern and southern males.

Given the timing, the researchers say the schism was likely triggered by a power struggle between three high-ranking males. The community’s troubles came amid rising tensions between a recently crowned alpha male, Humphrey, and his southern rivals Charlie and Hugh.

Humphrey was a top-ranking male chimpanzee in Gombe National Park, Tanzania, in the early 1970s and known for his frequent attacks on other chimps. Tensions between Humphrey and his southern rivals Charlie and Hugh may have triggered the only known civil war in wild chimpanzees, researchers say. Photo by Geza Teleki.

“Humphrey was large, and he was known to throw rocks, which was scary,” Pusey said. “He was able to intimidate Charlie and Hugh separately, but when they were together he tended to keep out of the way.”

Their dominance struggle was likely exacerbated by competition for reproductively cycling females, whose availability was unusually low, the researchers found.

The resulting hostility was not restricted to these rival males; it affected the whole web of social ties the males were embedded within.

“It’s not possible to say for sure that any one thing was causal since this is the only such event we’ve ever seen in chimpanzees,” Feldblum said. But the results mirror what researchers have documented in other primates, including humans.

A previous analysis of schisms in nearly 50 human societies worldwide found that internal political conflict frequently foreshadows a split in human groups as well, followed closely by competition for scarce resources.

Collectively, the findings suggest that such social dynamics are deeply rooted in the primate evolutionary tree.

“Understanding why cohesion breaks down can give you clues about the forces that bind social groups together in the first place,” Feldblum said.

Other authors include Sofia Manfredi of Duke and Ian Gilby of Arizona State University.

This research was supported by the Jane Goodall Institute, and grants from the National Science Foundation (BCS-9021946, BCS-9319909, BCS-0452315, IIS-0431141, IOS-LTREB-1052693, DGE-1106401), the Harris Steel Group, the Windibrow Foundation, The Leakey Foundation, the University of Minnesota and Duke University.

CITATION: “The Timing and Causes of a Unique Chimpanzee Community Fission Preceding Gombe’s Four Years’ War,” Joseph Feldblum, Sofia Manfredi, Ian Gilby and Anne Pusey. American Journal of Physical Anthropology, March 22, 2018.