Nathan Thompson is a PhD candidate at Stony Brook University who was awarded a Leakey Foundation research grant in the spring of 2014. He and his team were published in this month's issue of Nature Communications, and he has been kind enough to provide us a brief summary of the article. 

Compared to our great ape relatives, humans possess a long and flexible trunk (the part of the body that includes the ribcage, belly, and pelvis). Chimpanzees (as well as other great apes) have a trunk that is typically described as being rigid and block like. The chimpanzee trunk is presumably adapted for a life of tree-climbing, but probably not so great for bipedal walking. This is because during bipedal walking in humans, the ribcage and arms rotate in one direction, while the legs and pelvis move in the opposite direction. You can see this as your arms and legs move in opposite directions when you walk. These opposite rotations are beneficial because they help to conserve a physical quantity called ‘angular momentum’. The angular momentum of the upper body cancels out the angular momentum of the lower body. In humans, this helps to reduce work, and saves energy during locomotion.

But how far back this ability extends into our family tree is a mystery. Though likely present by the time of Homo erectus, early hominins like Lucy (Australopithecus afarensis) display similarities in their ribcage and pelvis to chimpanzees, which suggests they may have possessed an ape-like rigid trunk. A rigid trunk would mean no opposite rotations between the ribcage and pelvis, and would have potentially limited bipedal performance in australopithecines.  

Using a high-speed motion tracking system, we tracked how the trunk of chimpanzees and humans actually moves during bipedal locomotion. To our surprise, we actually found the same amount of motion between the pelvis and ribcage in chimpanzees as in humans. This means that chimpanzee trunks are not actually that rigid. Thus, the ability to move the rib cage to counter the pelvis is present in chimpanzees, and was likely already present in early hominins.

This image depicts pelvis and ribcage rotations during bipedal locomotion. Despite differences in overall motion, there is as much mobility between the pelvis and ribcage in humans as in chimpanzees, suggesting more human-like abilities in our earliest ancestors than previously thought. Credit: Nathan Thompson, Lucille Betti-Nash, and Deming Yang.

The real difference between the two species was in how much they rotated their pelvis. Chimpanzees rotate their pelvis so much that they can’t use their upper body to cancel out angular momentum of their lower body, unlike modern humans. Large pelvic rotations during bipedalism seem to be the primitive condition for non-human primates, so only when human ancestors were able to reduce hip rotation, would they have been able to utilize their upper body to balance angular momentum, and increase walking efficiency. We found that if Lucy were able to reduce her hip rotations to within 150% of the modern human level, she would have been able to rotate her trunk in a human-like way. This would have potentially allowed our early hominin ancestors to decrease work and increase efficiency during bipedal locomotion.

Currently, we are examining what other effects a chimpanzee-like trunk might have on whole-body mechanics of bipedal locomotion. The fact that the basic dichotomy of ‘rigid chimp-like’ and ‘non-rigid human-like’ trunk morphologies don’t hold up, shows us that we have a lot to learn about how our closest relatives actually move. 

What can we learn from chimps swinging their hips? In this Nature Video, we investigate the walking style of our primate cousins, and see what they can teach us about our ambling ancestors. 

You may read the full article in Nature Communications by clicking here


AuthorH Gregory
CategoriesJournal Article

This is a photo of me trying to coax a stick bug off of the Kiahera Formation paleosol we were measuring. Photo credit:  Lauren Michel

Niki Garrett is a PhD candidate from the University of Minnesota. She was awarded a Leakey Foundation research grant in the fall of 2013 for her project entitled "Compound specific paleoecology of Early Miocene hominoids from East Africa." Here is a brief description of her research followed by a report from the field.

I am interested in the relationship between ecological/climate change and primate evolution.  The aim of this study is to obtain detailed paleoenvironmental reconstructions of the Early Miocene (~15-20 Ma) fossiliferous sediments on Rusinga Island, Kenya, in order to clarify our knowledge of the habitats that supported some of the earliest fossil apes. The fossil deposits on Rusinga Island contain some of the richest samples of Early Miocene floral and faunal communities, including many partial skeletons of the putative hominoid Ekembo (Proconsul), fossils from the less well-known catarrhines Limnopithecus and Nyanzapithecus, and three strepsirhine genera Komba, Progalago, and Mioeuoticus. These sites provide an excellent setting to examine the adaptation and diversification of catarrhines and early hominoids, which is a necessary foundation for our understanding of the evolutionary history of all apes including humans.

From left to right (back row): Joshua Siembo, Francis Sina Muteti, Niki Garrett, Collins Ouma Ogongo, and Joel Torgeson.  Front row is a group of local kids from the island.  Taken at the “bovid hill” site. Photo credit:  Lauren Michel

Relatively new molecular proxies will be utilized in this study to augment previous paleoenvironmental reconstructions. Specifically, compound specific hydrogen and carbon isotope analysis of plant leaf waxes (n-alkanes and n-alkanoic acids) preserved in the paleosol and lacustrine sediments. In a C3-only ecosystem, such as those found in the Early Miocene, carbon and hydrogen isotope analyses have the ability to inform our understanding of the density or open/closed nature of the local habitats. This research will provide a paleoenvironmental context for not only this important primate community, but also the extensive mammalian faunal community, as well as to provide documentation of any temporal or spatial changes in habitat during the Early Miocene.

Joel Torgeson (L) and Lauren Michel (R) standing in the middle of the exposed Kiahera Formation paleosol trench. Photo credit:  Niki Garrett

The Leakey Foundation research grant afforded me the opportunity to travel to Rusinga Island, Kenya for a third research trip this past August. First explored in the 1930s by members of the third East African Archaeological Expedition led by L.S.B. Leakey and D.G. MacInnes, fossil deposits on Rusinga Island contain some of the richest samples of Early Miocene floral and faunal communities, including the largest known collection of the primitive hominoid Ekembo (Proconsul). Vertebrate fossils from more than 90 species of mammals are known from the Early Miocene Rusinga Group, which comprises in stratigraphic order, the Wayando Formation, Kiahera Formation, Rusinga Agglomerate, Hiwegi Formation, and Kulu Formation. Renewed research has provided important new insights into the geological and paleoenvironmental context for these deposits including new age constraints for the Kulu Formation (~15-17 Ma) and for older formations (~18-20 Ma). Although decades of research at these sites have produced multiple paleoenvironmental studies, a clear consensus has yet to be reached regarding the ecological context for Rusinga's early apes and other catarrhine primates. Most previous paleoenvironmental research has focused on the highly fossiliferous Hiwegi Formation. The aim of my research is to obtain detailed paleoenvironmental reconstructions for the entire sequence of Early Miocene fossiliferous sediments allowing for documentation of any temporal changes and providing a detailed picture of the habitats utilized by these primates at a critical period in the evolutionary history of hominoids.

Lauren Michel (R) interacting with some of the local kids at the “bovid hill” site. Photo credit:  Niki Garrett

 The primary goal of this trip was to collect lacustrine and paleosol samples from the Kulu and Kiahera Formations for compound (n‑alkane and n-alkanoic acid) specific carbon and hydrogen isotope analyses (CSIA). Compared to previous field seasons, this trip was very quick and involved a relatively small field team. In addition to three Kenyans (Francis Sina Muteti from the National Museums of Kenya, and Joshua Siembo and Collins Ouma Ogongo from Rusinga Island), I traveled with Dr. Lauren Michel (geologist, current postdoctoral researcher at Southern Methodist University, Dallas, Texas) and Joel Torgeson (field assistant, undergraduate at the University of Minnesota).  The six of us spent a total of nine days at various sites around the island assessing the suitability of the formations and deposits for this, and future, research. One of the main factors to be considered when identifying and collecting sediment samples for CSIA are modern contaminants. Sediment samples need to be completely free of modern roots and other plant materials. At some of the Rusinga Island sites, we found this to be nearly impossible making those sites/sediments unsuitable for this specific type of research. On one day in particular, this was a pervasive problem.  We spent one Sunday at multiple sites within two localities, and I was unable to collect a single suitable sample for CSIA. It was noted that the roots appeared to be following the specific layers I was targeting, and no amount of trenching into the hills appeared to uncover sediments without visible modern plant roots - the paleosol sediments were as appealing to the plants as they were to me (although for very different reasons), however the plants got there first!

Joel Torgeson (L) and Lauren Michel (R) standing in the middle of the exposed Kiahera Formation paleosol trench. Photo credit:  Niki Garrett

In the end, I was able to find multiple suitable sampling sites free of modern plants. I collected samples of the lacustrine deposits in the Kulu and Kiahera Formations.  We were also able to identify and describe ~2.3 meters of exposed paleosol in the Kiahera Formation where I also collected CSIA samples. I collected these samples using a protocol that ensures they are not contaminated by other sources of organic matter, such as oils from my hands, sunscreen, or plastic bags.

The next step in this research is to travel to the Lamont-Doherty Earth Observatory (Columbia University, NY) where I will extract and isolate the n-alkanes and n-alkanoic acids from the sediments. Long, straight‑chain (i.e., normal, n‑) alkanes and alkanoic acids are the primary components of the protective waxes that coat the leaf surface of almost all land plants. Because these compounds are extremely environmentally persistent in sediments over geologic time and are resistant to biodegradation, they serve as an exceptional proxy for ancient vegetation in terrestrial or terrigenous sediments. Once these compounds are extracted and purified, I will analyze the abundance and distribution of the alkanes and alkanoic acids, as well as the carbon and hydrogen isotopic compositions of the target compounds. These steps will provide me with information on how “open” or “closed” the local habitats were on Rusinga Island during this period, allowing for a robust evaluation of the variability in the C3 ecosystems inhabited by the Early Miocene catarrhines including the earliest hominoids. 



AuthorH Gregory

John Hoffecker

John Hoffecker of the University of Colorado has been awarded 13 grants from The Leakey Foundation for his research at various sites in Eastern Europe. He has been awarded three for work at Shlyakh, an open-air Paleolithic site located in the Volgograd region of Russia. The most recent Leakey grant for this site was awarded in the spring of 2013.

In August 2013 Hoffecker and his team performed fieldwork at Shlyakh in order to establish a firmer chronology for the main occupation layers, which contain a Levallois blade and point industry.  In the report below, Hoffecker shares the results of this fieldwork and describes how this site may represent a modern human presence on the southern plain of Eastern Europe. 

AuthorH Gregory
CategoriesResearch Report

Tanya Smith (R) and co-PI Zarin Machanda (L)

 Tanya Smith , Associate Professor at Harvard was awarded a Leakey Foundation research grant in the spring of 2012 for her project entitled "Tooth eruption and life history in living chimpanzees."

Tanya Smith and her team study dental development patterns in chimpanzees in order to better understand the evolution of human development.  Previous research on chimpanzee dental development has been performed on either captive animals or on deceased individuals, and it has been unclear whether the developmental trajectories derived from these data accurately reflect those of wild chimpanzees. So, Tanya Smith and her team set out to record dental emergence ages of living wild chimpanzees using novel photographic methods in order to generate a comparative sample of dental eruption standards and associated life history information. 

The team photographed the Kanyawara community of chimpanzees in Kibale National Park, Uganda, over the course of three years. These data were then compared to long-term behavioral and life history datasets from the same population. 

Two research papers have been published as a result of this project. In their paper published in PNAS, we learn how the eruption of the first molar in the Kayawara chimps compares to that of captive chimps as well as current estimates in australopiths. The second paper was published in the Journal of Human Evolution, and it describes how their comprehensive three-year record of dental eruption compares to records from captive chimps, living chimps from Gombe and deceased individuals at Taï.

In the report below, Smith summarizes the results of this project.  

AuthorH Gregory
CategoriesResearch Report

Villaseñor (L) sorting through sediment to find microfauna

Amelia Villaseñor was awarded a Leakey Foundation research grant during our spring 2015 cycle for her project entitled "The biogeography and behavioral ecology of hominins in Pliocene Eastern Africa:  A macroecological perspective."

The East Africa rift valley well known as the home to some to some of our most famous hominin ancestors: from Lucy to the Nutcracker man to the Turkana boy. Less well known are the decades of paleoecological data that accompany these finds. For every hominin fossil, hundreds of mammalian fossils are collected and documented, from hyenas to hyraxes, which make up the mammalian “community” of which hominins were a part and provide important environmental information. These decades of fossil data, combined with geochemical data from sediments in which fossils are found, were begging to be compiled and provide new insight into the ecology of early hominins.

Map of study sites correlated by the Tulu Bor tuff to 3.42Ma

This is where I come in.

My research investigates how expanding savanna environments influenced early hominin ecology (circa 3.5 million years), including behaviors such as exploiting a new dietary niche and stone tool use. Recent work suggests that the answer to this question is not straightforward since different ecological proxies, such as fossils and isotopes, tell different stories. For example, paleoecological reconstructions from soil isotopes conducted in the eastern African Afar and Turkana basins found that landscapes were more open during earlier time periods (~4.4 million years ago) and became a more woody “mosaic” during the time period of this study (3.6–3.2 Ma). The complex part of the story, however, is that Australopithecines, such as Lucy, and other contemporaneous hominin species begin to incorporate resources from more open environments, such as grasslands, during these more woody time periods. One way to begin to understand how ancient environmental conditions may have affected hominin behavior is to understand the variation of environments and mammalian communities across space.

Villaseñor collecting soil samples from a hillside in East Turkana, Kenya

My dissertation research thus seeks to bring some clarity to this picture by comparing the ecology of several rift valley sites in Ethiopia and Kenya where we have hundreds of mammalian fossils from this period. Specifically, I am comparing fossil and isotope data (from both soil and teeth) that I collect from East Turkana, Kenya to data from West Turkana, the Omo-Shungura, Ethiopia and Hadar/Dikika, Ethiopia. These sites are temporally correlated by a volcanic tuff that dates to 3.42 million years old. The proposed research will make a substantial impact on the discussion of how ancient environments affected early hominin behavioral ecology by illuminating how contemporaneous hominin sites vary across space. In particular, stone tool use is one of the hallmarks of human uniqueness and recent discoveries of tool use in West Turkana, Kenya and Dikika, Ethiopia at 3.3Ma and 3.4Ma, respectively, make these regions a point of particular interest for understanding the ecology and biogeography of early hominins to give context to these early, distinctive behaviors. 

A fossil juvenile hippo pelvis in situ

AuthorH Gregory

Claudia Wilke

Claudia Wilke is a PhD candidate at the University of York in the United Kingdom. She was awarded a Leakey Foundation research grant during our fall 2013 cycle for her project entitled "Are cooperative chimpanzees more communicative (Kibale Forest, Uganda)?" Here she gives us an update on her field season and how her research is progressing.

My time at Kibale Chimpanzee Project (KCP) went surprisingly quickly, and luckily I encountered no major difficulties. As I was already familiar with the chimps, the field assistants and the forest from my pilot season, this made it much easier to get back into the field routine. The overall aim of the project was still to establish how communicative and cooperative each focal animal was, in order then to explore the relationship between these variables and establish whether those that are more communicative are also more cooperative – as a coevolution of these two cognitive capacities has often been proposed. I wanted to adopt a multimodal approach to establishing how communicative an individual was; therefore, as part of the project, I have also collected a valuable and rich data set on multimodal communication in wild chimpanzees. As little is known about multimodal communication in wild chimpanzees, I aim to capitalise on this data set, and as soon as the data are extracted, prepare a paper for publication detailing aspects of both production and reception of multimodal signals compared to their unimodal constituent signals (vocalisations, gesture and facial expression).

On each day in the forest, once I had found a party of chimps (either by listening for long distance calls or going to the location where chimps had been seen to nest the night before), I identified the individuals for which I had the least focal filming time and then made these chimps the priority to film – altogether I had 26 individuals which I collected data for. I kept a notebook with the number of minutes I already had for each individual, in each behavioural context (rest, feed, groom, travel, play), and focused on trying to keep the times in these contexts equal for each individual and between individuals. This worked well, though it was still much trickier to get certain individuals in certain contexts than others. For instance, some of the older males do not spend as much time playing as the mothers do with their offspring, and some of the females are much harder to follow when traveling than the males are. As I only filmed each individual once per day for one 15 minute focal sample period, this meant it was best to find large parties, with many individuals. Of course not all individuals could be found on every day, and on the days when we only had a small party, once I had finished with the available individuals, I could go back to camp and do some video coding.

During August 2014 almost the entire community went to the very north of their territory, leaving behind only a few females, and as the field assistants do not follow the chimps when they are so far away and ‘off-grid’ (away from the maintained path system), I had quite a few weeks of following the same females every day. Although this was frustrating in some ways, it enabled me to make good progress with my video coding, and I finished my field season with roughly a quarter of my videos coded, making the coding job on my return to the UK a bit less daunting. Another pleasant surprise in this otherwise quiet period was that several of the females I collected data on gave birth - this was very exciting, and the four babies are still doing well today.

For the cooperation aspect of the data collection, this was slightly less fruitful, as this community of chimps engages in behaviours such as hunting, boundary patrolling and intercommunity encounters quite rarely. However, I have details of all the hunts and intercommunity encounters that did take place during the data collection period (there were no boundary patrols) and managed to collect plenty of data on grooming interactions and reciprocation. To supplement my own rather sparse data on some aspects of cooperative behaviour, I have also been given permission to use the long term data from the project on these behaviours, which if examined over a longer time period will give a better estimate of cooperative tendencies than my data alone. One of the big differences in this field season compared to my pilot period was having a research assistant to aid filming communicative signal production and reception in more detail. This was only possible because of your funding and the difference to the quality of the data collected was considerable.

Generally, one person would focus closely on the focal animal, whilst the other zoomed out to capture responses from the potential recipients surrounding the focal animal. This worked best when all the individuals were together on the ground, sitting on a path, or when there were only two individuals in the party and each person could film one chimp. The extra person and camera also came in useful when the focal individual frequently moved or turned and it was difficult for the primary filmer to move. In this case one camera could only capture all the signals produced for some of the time – and if the other person could walk around to the other side of the tree, or other side of the group of chimps, they could capture the focal signal production from this side – thus having almost a 360 degree view of the focal animal at all times and making sure the face and hands were almost always visible so we could capture visual signals effectively.

During this field period I managed to collect almost 800 focal videos. This was my realistic aim, as I had assumed that the rains would make data collection difficult or impossible for at least one or two months – although in the end the rains did not have as much of an impact as the month when most of the community was away in the North. Of these videos I have already coded half and am working on the rest. As it takes between one and four hours to code each video (usually around two/three hours), I may not have time to code all videos – however again I am making sure I code an equal amount of time for all individuals and am focusing on the best-quality videos first.

Once this video coding is finished I will be able to report the frequency and types of unimodal and multimodal communication produced – I will also be able to look at the effects of age, sex, rank, party composition and behavioural context. Furthermore, I will investigate the frequency and types of responses these signals elicit from the recipients/audience and how this is influenced by different factors. This has not previously been reported for a wild chimp community and will hopefully shed more light on the complexity of their communication system. These data will also form the basis for the calculation of a ‘communicative’ index to compare to the cooperative index I will calculate from both my observations and the long term data on cooperative behaviours. Additionally, whilst in the field I became interested in some of the more commonly produced gestural signals (big loud scratch and hand clasp grooming), and I aim to use my detailed video data to explore the functions of these signals. 

AuthorH Gregory
CategoriesFrom the Field

When we dart a baboon, we process it near its social group so that the animal can be released quickly and efficiently once it recovers from the anesthetic. We take the collected samples back to our permanent tent camp on the edge of Amboseli National Park. There, I work to further process all blood and tissue for temporary storage and eventual export to the United States. Here is a picture of me, happily processing samples, in our makeshift tent ‘laboratory’. Photo credit: Jenny Tung

This January we introduced you to Amanda Lea.  She was awarded a Leakey Foundation research grant in our fall 2014 cycle for her project entitled "Effects of social conditions on DNA methylation and immune function." Here she updates us on the her latest field season.

I was recently funded by the Leakey Foundation to investigate how social conditions influence gene regulation in wild baboons. Many primate species, including humans, live in complex social environments, and research across primate species has demonstrated a robust link between poor quality social conditions (e.g., social isolation or low social status) and compromised health. Thus, it appears that social experiences can profoundly shape fitness-related traits in primates; however, our understanding how this occurs at the molecular level is extremely incomplete. To address this gap, my project tests the hypothesis that social adversity influences health-related traits by altering the way genes are expressed. To do so, I am combining behavioral data from a well-studied population of yellow baboons with genome-wide profiles of DNA methylation (an epigenetic gene regulatory mechanism) and gene expression levels.

An important component of the baboon social environment is grooming, shown here, which is a primary mechanism for forming and maintaining social relationships. 

I recently returned from my third field season in Amboseli, where I was working to collect blood samples from baboons for my genomic work. The baboons that I study are part of a long-term project headed by Jeanne Altmann, Susan Alberts, Beth Archie, and Jenny Tung. The project is known as ‘The Amboseli Baboon Project’ (ABRP), and has been ongoing for over four decades. Animals in the study population are regularly monitored by a highly skilled team of field observers and are occasionally darted to collect blood samples for genetic and genomic analyses. The ABRP has been darting animals for many years using a conservative darting protocol that is aimed at maximizing safety and preserving the habituation of the study animals. Animals are generally darted very early in the morning, using a hand held blow gun carrying an anesthetic-bearing dart. Once the animal is anesthetized, it is quickly moved away from its social group to a nearby processing area. There, we work quickly to collect blood and tissue samples, morphological measurements, and information about tooth wear. Following this effort, the sedated animal is allowed to regain consciousness in a covered holding cage, and is then released near its social group upon recovery and closely monitored. This entire process can take quite some time, and requires extensive preparation. Most importantly, a successful darting and sample collection effort relies on the participation and expertise of many skilled researchers and field assistants.

We take a long list of laboratory supplies into the field with us on darting days. These supplies are for drawing and processing blood and tissue, taking morphological measurements, and documenting tooth wear patterns in each animal we dart.

I was able to participate in this darting effort over the course of the summer (thanks to funding from the Leakey Foundation), and successfully collected blood from twenty baboons during my field season. Importantly, all of the individuals I collected samples from were born in the study population and have been monitored by the ABRP for their entire life. Therefore, I can link my genomic data with extremely fine-grained information about the social conditions each individual has experienced, from birth through adulthood. I plan to return next summer for another field season and look forward to collecting another set of samples and spending more time with the baboons. For now, I am busy extracting DNA and RNA from the samples I collected this year and preparing them for high-throughput sequencing (to measure genome-wide DNA methylation and gene expression levels).

AuthorH Gregory
CategoriesFrom the Field

Nancy Stevens

Nancy Stevens is a professor at Ohio University. She was awarded a Leakey Foundation research grant in the spring of 2011 for her project entitled "Oligocene primates from the Nsungwe Formation of Tanzania."

The late Oligocene Nsungwe Formation (~25Ma) is located in the Rukwa Rift Basin in southwestern Tanzania. These deposits represent the only late Oligocene primate fossil bearing sites in sub-equatorial Africa. This fossiliferous rich, yet under-sampled locality offers the opportunity to address numerous questions about primate evolutionary history.

In the report below, Nancy Stevens describes the results of her team's four week field effort in the dry season of 2011. These results include the discovery of the earliest stem cercopithecoid primate as well as other significant vertebrate finds.

AuthorH Gregory
CategoriesResearch Report

Iulia Badescu

Iulia Badescu is a PhD candidate at the University of Toronto. She was awarded a Leakey Foundation research grant during our 2015 spring cycle for her project entitled "Investigating the infant nutritional development of wild chimpanzees."

I am investigating the infant nutritional development of chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda. Infant nutritional development is the time from complete dependence on maternal milk to nutritional independence, and includes three stages: exclusive suckling, transitional feeding (from first solid food consumption to suckling cessation) and weaning. Little is known about chimpanzee infant diets and mother-infant interactions. A model of infant nutritional development in wild chimpanzees is required to better understand the evolution of human infant feeding and care, and my project will acquire the primary data needed to achieve this task. Identifying the key differences and similarities between the nutritional development of chimpanzees, humans and other primates will help us delineate the evolutionary forces responsible for the variable patterns of infant feeding shown across primates and within contemporary human populations.

I am using a combination of behavioral and fecal stable isotope data to track the progression of infants’ diets from 100% maternal milk to 100% adult foods. My aim is to quantitatively document each stage of infant nutritional development, and the development of ecological competence in wild chimpanzees. Over 11 months at Ngogo, I watched infants nurse, forage, learn to eat solid foods, and interact socially with their mothers and others. With the help of two field assistants, I collected almost 1000 fecal samples from infants and their mothers. I am currently working in the Archeological Chemistry Lab and Isotope Sciences Lab at the University of Calgary to determine the stable isotope compositions (δ15N, δ13C, %N) of the fecal samples collected.

The stable isotopes of various foods are reflected in the tissues and feces of consumers. Chimpanzee infants consuming mostly maternal milk show different fecal stable isotope profiles than their mothers, who eat a plant-based diet. As infants progress through transitional feeding and weaning, their isotope profiles gradually resemble those of their mothers until they are identical, when weaning is complete. It is useful to compare isotopic assessments of infant diets with observations of nursing and feeding because behavioral data alone may not allow primatologists to reliably document nutritional development. An infant may appear weaned from daytime observations but may continue to nurse at night, when observations are not conducted. Alternatively, a weaned individual that continues to contact the mother’s nipple for comfort rather than nutrition may be classified inaccurately as a nursing infant from observations. To remedy these observational limitations, I will compare my behavioral data of nursing and infant feeding with stable isotopes (δ13C, δ15N, %N) of fecal samples collected during the same time period. This comparison will identify any discordances between the behavioral and isotopic assessments of infants’ diets, and allow me to reliably determine the timing and duration of infant nutritional development in wild chimpanzees.

I am grateful to the Leakey Foundation for funding the stable isotope laboratory analyses. This research is only possible with the support of my supervisor, Dr. Daniel Sellen (University of Toronto) and our collaborators, Drs. Anne Katzenberg (University of Calgary), David Watts (Yale University), Kevin Langergraber (Arizona State University), and John Mitani (University of Michigan). 

AuthorH Gregory
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Alia Gurtov at Olduvai Gorge, Tanzania.

This January we introduced you to fall 2014 grantee Alia Gurtov. Here she updates us on the progress of her project entitled "Dental microwear analysis of Early Pleistocene hominin foraging seasonality." 

I have long been interested in the ecological constraints on ancient human behavior. For my PhD research, I am studying the impact of seasonality on hominin foraging in the Early Pleistocene. By 2 million years ago in eastern Africa, the environment was periodically very similar to that of today, with a general trend toward aridity and dramatically different wet and dry season conditions. In this newly challenging seasonal cycle, early hominins faced adaptive pressure to modify their foraging behaviors to accommodate the changing distirbution of edible foods. It s also happens to be the first time we see hominins eating a substantial amount of meat. (Notably, this seasonal discrepency was remarked upon by Leakey Foundation Grantee Oliver Paine in the context of South African herbivores adjusting their diets to the few available foods in the dry season. You can read about it here.)

Olduvai Gorge, seen from the top of Naibor Soit inselburg

Since 2011 I have worked at a site in Olduvai Gorge, Tanzania, called FLK North, which was initially excavated by Mary and Louis Leakey in the 1960s. Though it contains numerous stone tools, recent taphonomic studies indicate that its even more abundant faunal assemblage was primarily accumulated by carnivores, not hominins. In contrast, FLK Zinj, which is famous for producing the first Paranthropus boisei skull, aka Nutcracker Man, is a dense concentration of animal bones and stone tools with a key source of evidence connecting them: cut marks. FLK North and FLK Zinj have the same animals, stone tool technology, and paleoenvironment. As such, they provide a perfect opportunity to compare the meat foraging behaviors of hominins and carnivores in the highly seasonal context of the eastern African Early Pleistocene.  

 Modern impala and Grant's gazelles hanging out together near Lake Masek

With the support of the Leakey Foundation, I am now in the final stages of data collection, which I will complete in late August. In order to examine hominin foraging on a seasonal scale, I study the teeth of the animals they were eating, specifically the bovids Parmularius altidens and Antidorcas recki, both of which are abundant at FLK Zinj and FLK North. In a pilot study on modern impala, I demonstrated that the microscopic pits and scratches created by chewing differ significantly between wet and dry seasons, when impala are eating different foods (and different quantities of airborne grit!). Using the same approach, I can use a confocal microscope to analyze casts of bovids from Olduvai Gorge to see in which season they were eaten by hominins and FLK Zinj, and carnivores at FLK North.

Alia Gurtov molding Parmularius altidens teeth

This February, 2015, I traveled to Nashville, TN, to work in The DeSantis DREAM Lab in the Earth and Environmental Sciences Department at Vanderbilt University. During the two weeks there, I analyzed dental microwear on tooth casts of extinct bovids from Olduvai Gorge. This process is one of intensive microscopy and statistical analysis, which required occasional hot chicken and live music breaks. By the end of the two weeks, I had weathered an ice storm, met future collaborators, and analyzed roughly 150 teeth. 

Parmularius altidens teeth at the National Museum in Dar es Salaam

In June, I flew to Dar es Salaam, Tanzania, where the Louis and Mary Leakey fossil collections from Olduvai Gorge are stored. These fossils provide an inestimably valuable window into ancient hominin behavior and ecology in eastern Africa starting 1.9 million years ago. Because they have only recently been rehoused in Tanzania, part of my work at the museum included finding, organizing, and labeling the bovid assemblages from FLK North and FLK Zinj. Once done, I determined the minimum number of individuals represented by first and second molars among taxa of interest, including Parmularis altidens and Antidorcas recki. To this original sample, I added teeth excavated by The Olduvai Paleoanthropology and Paleoecology Project between 2008 - 2013. It was great to see some of these familiar fossil friends again. Once the associations between teeth were clear, I sampled all the undamaged first and second molars using Patterson dental impression paste, which forms vinyl molds capable of recording pits and scratches at the micron scale. 

Immediately upon my return to Madison (that is, that very night!), I prepared the molds and cast them with Epotek 301 epoxy. I now eagerly await their curing so that I can finish analyzing them in Nashville this August. 

To hear the end of the story, please join me at the 2016 American Association of Physical Anthropologists, where I plan to present my findings.

AuthorH Gregory
CategoriesFrom the Field

María Martinon-Torres at the Atapuerca sites. Photo credit: A. Canet.

María Martinon-Torres was awarded a Leakey Foundation research grant in the fall of 2012 for her project entitled "Micro-CT study of the Pleistocene human fossil teeth from Atapuerca."

By allowing researchers to reconstruct the internal structures of fossil dental samples, MicroCT provides a new dataset of variables to characterize and compare human populations, and so this technique provides way to test taxonomic and phylogenetic hypotheses based on classic morphometric studies. 

Martinon-Torres and her team focused on the microCT study of fossil dental samples from two sites in Atapuerca (Burgos, Spain), which has provided the most representative remains to help understand human evolution during the Pleistocene in Europe. These two sites, Gran Dolina-TD6 and Sima de los Huesos, are from the Early Pleistocene and Middle Pleistocene respectively. 

Dental Anthropology Group at CENIEH. From left to right: Cecilia García Campos, Laura Martín-Francés, Marina Martínez de Pinillos, María Martinón-Torres, José María Bermúdez de Castro and Mario Modesto Mata.

In the report below, Martinon-Torres describes her teams progress in exploring the phylogenetic relationship between Early and Middle Pleistocene populations of Europe and testing hypothesis about the origin of neanderthals. 

María Martinon-Torres studying the Sima de los Huesos dental sample. Photo credit: E. Lacasa.

AuthorH Gregory
CategoriesResearch Report

Davide Faggionato

Davide Faggionato was awarded a Leakey Foundation research grant during our spring 2015 cycle for his project entitled "Molecular and functional analysis of vision in three hominin species."

Hominin paleogenomics, the study of genomes retrieved from fossil hominin remains, has revolutionized the way we study human evolution.  For the first time, we can sample DNA from archaic humans deceased tens of thousands of years ago and decipher their genetic code, the instructions inscribed in their chromosomes.  Using this information we are now able to reconstruct virtually every gene in the genome of a Neanderthal or archaic human and test its function. By comparing the function of reconstructed genes to our modern version of the same gene, we can learn about the genetic differences between us and them: What do we have in common with early hominids, what made us special, or what made them unique.  Reconstruction of genes from extinct species allows an unprecedented insight into how individuals behaved and perceived the world, what diseases might have affected them, and maybe even unveil differences in their brain chemistry.

Davide Faggionato looking at some human DNA fragments to clone for the project.

In this project founded by the Leakey Foundation, I will study the genes responsible for vision and light perception. I will analyze their sequence and, if it is different from modern humans, I will “resurrect” the ancient genes in the laboratory and test their function. With this research I try to answer the profound questions: How did a Neanderthal or an archaic human observe their world? Did they perceive their surroundings like us or in a different way?

To accomplish these research objectives I will develop bioinformatics and molecular tools that will allow the exploration of virtually all genes in human paleogenomes. Future use of this methodology in combination with paleontological data has the potential to revolutionize the understanding of our origins and those of our cousins, the Neanderthals.

I’d be happy to start a conversation with the followers of the Leakey Foundation and the readers of this blog. If you have any questions please leave a comment beneath this post, I will reply to your comments in future updates on this project. My Twitter account is @MonoAphesis

Davide Faggionato:  I am reading the article on ancient DNA from the popular science magazine "The Scientist."

AuthorH Gregory

This episode of Origin Stories is about what it takes to document the daily lives of chimpanzees, what we've learned, and how to handle all the data that's been collected during the longest running study of any animal in the wild.

In the 55 years since Louis Leakey sent Jane Goodall to the Gombe forest to study chimpanzees, we've learned a lot about the lives and behavior of these wonderful animals. This is thanks to the work of around 100 researchers and students and at least 50-70 Tanzanian field assistants who've spent their days watching the chimps and writing everything down. 

PhD candidate Emily Boehm just returned from 8 months at Gombe, where she studied the sexual behavior of female chimpanzees. She tells us what it's like to spend her days following chimps and collecting data on their behavior. 

Immigrant female chimpanzees Chema and Rumumba, engaging in some quality, though rare, bonding time. Photo courtesy of

Immigrant female chimpanzees Chema and Rumumba, engaging in some quality, though rare, bonding time. Photo courtesy of

Anne Pusey, a Leakey Foundation grantee and director of the Jane Goodall Institute Research Center at Duke University, shares the story of the evolution of data collection at Gombe. She also tells us about the origins of the Gombe Chimpanzee Database Project, which archives and organizes this invaluable scientific resource, making it available for researchers to use to answer new questions about chimpanzee behavior.  

Field notes in Kiswahili from the archive. Courtesy of the Jane Goodall Institute Research Center.

Field notes in Kiswahili from the archive. Courtesy of the Jane Goodall Institute Research Center.

Thanks to Anne Pusey, Emily Boehm, Joseph Feldblum and Kara Walker from Duke University. You can learn more about the Gombe Chimpanzee Project on their website

Jane Goodall and Anne Pusey with decades of research data. Photo by Megan Morr. Duke University Press Office.

Jane Goodall and Anne Pusey with decades of research data. Photo by Megan Morr. Duke University Press Office.

Since 1968, The Leakey Foundation has awarded 13 grants to Jane Goodall and over 20 grants to other researchers studying chimpanzees and baboons at Gombe. We continue to support primatology research at Gombe and at other sites around the world. 

Origin Stories is made possible by support from Wells Fargo Bank. Transcripts are provided by Adept Word Management.

AuthorMeredith Johnson

Stephen Chester screening for Paleocene plesiadapiforms and other mammal fossils in Montana. Photo credit:  Eric Sargis

As a PhD candidate at Yale University, Stephen Chester was awarded a Leakey Foundation research grant in the spring of 2010 for his project entitled “Origin and early evolutionary history of primates.”

Stephen Chester studies the fossils of plesiadapiforms. Plesiadapiforms are an extinct group of mammals from the Paleogene (66 to 23 million years ago) that are thought to be precursors to the primate order.  Using phylogenetic and functional analyses, Chester is helping us better understand the origin and earliest history of primates. In other words, what makes primates different from the rest of Mammalia?

Results from this project include the naming of two new species of micromomyids, a basal plesiadapiform family, as well as the description of a new genus.  In his team’s most recent paper published in PNAS, they describe the first known postcrania of the oldest plesiadapiform, Purgatorius. This also includes phylogenetic analyses that support all plesiadapiforms as primates.   

A reconstruction of the micromomyid plesiadapiform Dryomomys szalayi by Doug Boyer

Stephen Chester holding the ankle bones of Purgatorius. Photo credit:  Stephen Chester

AuthorH Gregory
CategoriesResearch Report

Ashley Hammond of the George Washington University was awarded a Leakey Foundation research grant during our spring 2015 cycle for her project entitled “Reconstructing phenotypic change of the pelvis in apes and humans.”

Ashley Hammond

I study how the skeletal anatomy of primates relates to locomotion. The hipbone differs dramatically among living primates adapted for different locomotion, and my research focuses on this bone to identify how, and from which type of ape ancestor, hominin bipedalism evolved. Unfortunately, hipbones are fragile and rarely preserved in the fossil record, leaving us with an incomplete picture of early hominin hipbone evolution.

My goal is to reconstruct the evolution of locomotor behaviors in apes and hominins. My study will model hipbone shape evolution, with a particular focus on furthering our understanding of what the pelvis of the chimpanzee-hominin last common ancestor (LCA) is expected to look like under different evolutionary scenarios. First, I will use 3D shape quantification methods to characterize hipbone shape in primates, testing the hypothesis that living great apes exhibit different hip morphologies. Second, I will reconstruct the expected hipbone morphology of the LCA using phylogenetically-informed quantitative methods incorporating fossil apes (such as Sivapithecus) as calibration points. This portion of my study will provide a rigorous 3D reconstruction of the expected hipbone shape for the LCA and allow me to evaluate claims that the LCA had a chimpanzee-like hipbone. Finally, I will model the evolutionary scenario with the highest statistical support that explains how modern ape and human hipbones evolved.

L to R: Louise Leakey, Ashley Hammond, Meave Leakey

With financial support from the Leakey Foundation, my study will shed light on hipbone shape evolution in apes and humans, and provide key insights about origins of human locomotion.



 Mountain gorilla (Gorilla beringei) pelvis

The following are three-dimensional PDF images of gorilla and baboon pelvises. Right click to save the PDFs then use Adobe Reader or Acrobat to view and interact with the image:  

Olive baboon (Papio anubis)

Mountain gorilla (Gorilla beringei) 

Siamang (Symphalangus syndactylu)


AuthorH Gregory

Part of the collection of crocodile fossils. Photo credit: Erik Seiffert. 

Erik Seiffert is an associate professor in the Department of Anatomical Sciences at Stony Brook University. He was awarded a Leakey Foundation research grant in 2006 for his project entitled "Exploration for Early Anthropoids and other Primates in Western Egypt."

Prompted by studies suggesting that anthropoid colonization of Afro-Arabia occurred later than previously thought, Erik Seiffert and a team of paleontologists spent a total of four weeks exploring terrestrial and near-shore sediments of Late Cretaceous age in the Dakhla and Kharga Oases of Western Egypt. Their goal was to recover vertebrate fossils.

MUVP members showing a local group of high school students the jacketed remains of Late Cretaceous fossils from the Western Desert of Egypt. 

The team discovered many important vertebrate fossils in the area and expanded the vertebrate fauna of these deposits to include dinosaurs and crocodiles, to name a few. However, no mammals were found during the initial trip or several return visits.

While the outcomes of this project were "disappointing" from a paleoanthropology perspective, important strides were made in numerous other areas, including the creation and expansion of the Mansoura University Vertebrate Paleontology Division (MUVP).  

AuthorH Gregory

Rebecca Miller is a researcher at the University of Liege. She was awarded a Leakey Foundation research grant during our spring 2015 cycle for her project entitled "The Middle-Upper Paleolithic transition at Trou Al'Wesse (Belgium)." Her co-investigators are John Stewart and Keith Wilkinson.

Rebecca Miller

Rebecca Miller

Trou Al’Wesse (literally 'cave of the wasp) is a narrow cave of approximately 30m length in the Liège province of Belgium. The Leakey Foundation funded part of the project is the completion of our investigation of the terrace fronting the cave. This terrace sequence ranges from the Late Mousterian to the Middle Neolithic. We will be excavating the lowest two units - the Late Mousterian (Unit 17) and the Middle to Upper Paleolithic transition (Unit 16) – that underlie the Early Upper Paleolithic (Unit 15). These three units formed during the period from ca. 50,000 years ago to 30,000 years ago. Our primary interest in this part of the sequence is to obtain new archaeological and palaeoenvironmental data that will help us to understand the nature of the Middle to Upper Paleolithic transition, a period when Neanderthals were disappearing and modern humans arrived in Europe.

Our objectives are:

  • Clarify the chronology of human occupations by obtaining AMS radiocarbon dates on bone and charcoal and OSL dates of the sediments, which will contribute to our understanding of the timing of Neanderthal extinctions and the arrival of anatomically modern humans in this part of North-west Europe
  • Identify climatic and environmental changes that would have affected humans, particularly in terms of the availability of plant and animal resources in cold and more temperate phases
  • Compare the behavior of Neanderthals and modern humans at this site and in the regional context in order to understand their strategies for adaptation.

We will be analyzing the stratigraphy to reconstruct site formation processes, the lithic assemblages to evaluate procurement strategies and tool production techniques, and faunal analyses to address both behavioral aspects (hunting/butchery, bone tool production/use) and paleoenvironmental and climate change.

AuthorH Gregory

Nicole Squyres is a PhD candidate from Johns Hopkins University. She was awarded a Leakey Foundation research grant in our fall 2014 cycle for her project entitled "Morphological variation in the distal femur of modern humans and fossil hominins."

Nicole Squyres

The Leakey Foundation Research Grant has funded my travels to several different skeletal collections both within the US and Europe as part of the data collection for my PhD. At these collections, I have used a portable NextEngine 3D laser scanner to collect detailed surface scans of modern human and Neanderthal femora. I am now using this set of scans to collect data in the form of linear measurements and 3D geometric morphometric point data, which I will use to test several hypotheses about human variation in distal femoral morphology and the evolution of the hominin knee. I am interested in the evolution of the human knee because our ability to walk bipedally is one of the most unique characteristics of the human species. The shape of the distal femur had to change significantly from the ancestral hominoid condition in order make this type of locomotion possible. Although this morphology has been evaluated in various fossil hominins, there is still debate on how to interpret potential differences in femoral morphology and therefore locomotor behavior between these species and modern humans. The goal of my project is to examine differences in knee shape between hominins and modern humans within the greater context of the overall variation in knee shape within modern humans.

Neanderthal femur

In January of 2015, I spent two weeks at the University of Tennessee in Knoxville TN. There, I collected scans of 60 skeletal individuals from the Native American Arikara population from South Dakota. In February of 2015, I spent two weeks at the University of Colorado Boulder where I collected scans of an additional 60 skeletal individuals from the Kulubnarti population of medieval Sudanese Nubia. In May-June of 2015 I travelled to Europe to collect additional data. In Brussels, I visited the Institut Royal des Sciences Naturellles de Belgique, where I collected scans of 5 African pygmy individuals as well as the Spy II Neanderthal specimen. I then visited Bonn, where I scanned the Neanderthal 1 individual at the Rheinisches Landesmuseum. Before receiving the Leakey Grant, I had also collected scans from three modern human populations at the Smithsonian museum in Washington, DC. Additionally, I had been sent scans of several australopith and early Homo femora from other researchers. My dataset of scans therefore consists of 291 modern human femora from six different populations and 13 fossil hominin femora from several different species.

Unfortunately, I was unable to visit either the Musee de l’Homme in Paris, or the National History Museum in London as proposed in my grant because collections at both museums have been closed for at least the next year while renovations are made to the collections. I was, however, able to obtain CT scans of the two Neanderthal specimens in Paris and will therefore be able to include these individuals in the project even though I could not visit them in person. At this point I have collected all of the scans needed to complete my research. I am currently in the process of taking linear measurements from the scans and of analyzing shape differences within the dataset using 3D geometric morphometrics. I will be presenting findings from this project at the American Association of Physical Anthropologists annual meeting this year. 

AuthorH Gregory
CategoriesFrom the Field

Tyler Faith is a researcher from the University of Queensland in Australia. He was awarded a Leakey Foundation research grant during our spring 2015 cycle for his project entitled "Middle Stone Age of the Gwasi and Uyoma Peninsulas, Kenya."