Grantee Spotlight: Rebecca Miller

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Rebecca Miller (University of Liege) was awarded a Leakey Foundation Research Grant for her project entitled “The Middle-Upper Paleolithic transition at Trou Al’Wesse (Belgium).” This is her second grant from The Leakey Foundation. You can read more about her 2015 season at this site by clicking here.

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Rebecca Miller

The replacement of Neandertals by modern humans during the Middle-Upper Paleolithic transition has been a longstanding debate with principal arguments focusing on either interspecific human competition or climatic driven environment change. Recently, dates ~36,000 uncal BP obtained from Spy Cave suggest that Neandertals persisted until relatively late in the area. Given that the earliest UP dates in Belgium are 34-33,000 uncal BP, Neandertals and modern humans may have been broadly contemporary. The terrace of the cave site of Trou Al’Wesse in Belgium has a largely unexcavated stratified sequence in units 17 to 15 (MIS 3-2) with Late Mousterian human occupations in unit 17 and Aurignacian in unit 15. It thus offers a good opportunity to obtain detailed behavioral, climatic and paleoenvironmental data for the MP-UP transition and to assess the degree to which climatic oscillations might have affected the presence of hominids in Northwest Europe. This project will ideally contribute to clarifying the timing of the end of the Neandertal occupation and the arrival of anatomically modern humans, changes in climatic and environmental context that affected human presence, and behavioral responses and adaptations to climate and environmental change across the transition

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Figure 1

The importance of this site (Figure 1) is due to a) its geographic location on a tributary south of the Meuse and thus relatively isolated from the concentration of other Belgian Paleolithic sites in the eastern and western parts of the Meuse Basin, b) evidence of repeated human occupation during the Mousterian, Aurignacian, Mesolithic and Neolithic periods and c) the presence of a relatively complete stratigraphy from Marine Isotope Stage (MIS) 3 onwards (the terrace fronting the cave has a stratigraphic sequence spanning the period > 45,000 to 4,000 uncal BP) with which to study climate variability and environmental change associated with hominid activity.

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Figure 2

During the 2015 field season, funded by The Leakey Foundation, excavation was conducted in the L-M 4-10 rows in the middle of the zone containing units 17 and 16 (Figure 2). An interdisciplinary approach was applied to record the sedimentary context during excavation, analyze the geological data, lithic and faunal data, reconstruct the chronological framework for the Neandertal occupations and ultimately, the climatic and environmental context. This approach is based on microstratigraphic, taphonomic and spatial analyses to reconstruct site formation processes and evaluate the depositional context, analysis of the lithic assemblages (technology, typology, taphonomy, raw materials), analysis of the faunal assemblages to study behavioral aspects (prey choice, processing, bone tool production) and reconstruct environment and climate phases. Dating of the sequence using OSL and AMS is in progress to propose a chronology for human presence/absence and climatic and environmental change for the ca. 50,000-30,000 BP period covered.

We are all very pleased with the results of the 2015 season, and even more so that The Leakey Foundation has now funded a second season to continue the excavation of these units within the overall 5×4 m area containing this sequence. Alongside the ongoing lithic, faunal and geological analyses, additional analyses supported by the 2016 Leakey grant include near infrared spectroscopy to detect and evaluate collagen content in bone for sample selection prior to AMS dating, pollen analysis for paleoenvironmental reconstruction and LA-ICP-MS analysis in an exploratory study to source the lithic raw materials exploited at Trou Al’Wesse.

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Click here to read more about her team’s 2015 season at this site.

Video: The Secret Lives of Female Chimpanzees

A mother and baby chimpanzee. Photo by Kevin Langergraber.

Did you miss this summer’s speaker series event in Chicago? Well we have the full video right here!

On August 17, The Leakey Foundation in partnership with the Chicago Council of Science and Technology (C2ST) presented “The Secret Lives of Female Chimpanzees” with guest speaker Melissa Emery Thompson. We were honored to have Dr. Robert Martin from the Field Museum of Natural History and the University of Chicago introduce both organizations. Janice Bell Kaye, advisor to The Leakey Foundation, gave a warm welcome to Dr. Thompson.

Here is a short introduction to the talk

Female apes are easily overshadowed by their larger, more boisterous male counterparts. Thus, the nature of female social relationships has been shrouded in mystery. The subtlety of social behavior in female chimpanzees belies a complex set of strategies that allow them to navigate the costs and benefits of group life. By combining decades of behavioral research with innovative non-invasive approaches, Dr. Emery Thompson and her colleagues at the Kibale Chimpanzee Project have uncovered fascinating details about the secret lives of female chimpanzees. She will discuss how females negotiate rivalries to obtain the resources they need to reproduce, the chaotic, and sometimes violent, nature of sexual relationships with males, and the unexpected ways these relationships change with age. Along the way, you will learn about the challenges and rewards of studying this fascinating species in the wild.

Enjoy the video!

About Melissa Emery Thompson

Melissa Emery Thompson, Ph.D., is an assistant professor of anthropology at the University of New Mexico. She received her PhD in biological anthropology from Harvard in 2005. She has studied chimpanzee behavior and biology for eighteen years and serves on the board of directors of the Kibale Chimpanzee Project, one of the longest-running continuous field studies of great apes. While Dr. Emery Thompson is broadly interested in social behavior, her expertise is in developing and applying non-invasive methodologies for monitoring health and reproductive function in wild primates (and humans!). The Leakey Foundation has played an important role in supporting this research.

Interested in attending one of our upcoming events? Click here to visit our events page.

Grantee Spotlight: Evelyn Pain

Raoul surveying the forest

Evelyn Pain is currently a PhD candidate at Stony Brook University. She was awarded a Leakey Foundation Research Grant during our spring 2016 cycle for her project entitled “Functions of male woolly monkey morphological variation in Yasuní, Ecuador.” 

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Evelyn Pain

Sexual size dimorphism (the size difference between males and females) is thought to be driven by competition between males for access to females. Where direct male-male competition is more intense males are expected to be larger than females. While many primate species follow this pattern, there are intriguing exceptions that remain unexplained. Because estimates of sexual size dimorphism are a major tool for inferring the behavior of fossil hominins, understanding what causes deviations from the typical pattern will improve our understanding of human origins.

Grayson being approached by two juvenile males

Grayson being approached by two juvenile males

My dissertation research aims to explore factors affecting competition among male woolly monkeys (Lagothrix poeppigii) at the Tiputini Biodiversity Station in Yasuní, Ecuador. Woolly monkeys have higher sexual size dimorphism than expected considering the low levels of aggression observed between males. This project specifically examines whether variation among males in body size and hormone levels relates to access to females. Males in this species are highly variable in their morphology and body size, which may play a role in mitigating male-male competition. My team and I will be collecting data on male behavior, male size (remotely using scaled photographs), as well as testosterone and corticosterone (a stress hormone) levels (via fecal samples). Morphological variation within a sex has not been well studied and this will be one of the first projects to examine how this variation impacts competition.

Raoul surveying the forest

Raoul surveying the forest

Twenty-Five Little Bones Tell a Puzzling Story About Early Primate Evolution

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The extinct Gujarat primates appear to be most similar to the gray mouse lemur, Microcebus murinus, pictured here. Photo: David Haring, Duke Lemur Center

The extinct Gujarat primates appear to be most similar to the gray mouse lemur, Microcebus murinus, pictured here. Photo: David Haring, Duke Lemur Center

A cache of exquisitely preserved bones, found in a coal mine in the state of Gujarat, India, appear to be the most primitive primate bones yet discovered, according to an analysis led by researchers from The Johns Hopkins University and Des Moines University, funded in part by a grant from The Leakey Foundation. Their assessment of the bones, belonging to ancient, rat-sized, tree-dwelling primates, bolsters the controversial idea that primates native to what is now India played an important role in the very early evolution of primates, mammals that include humans, apes and monkeys.

A description of the research was published online August 7, 2016, in the Journal of Human Evolution.

“All other primate bones found so far around the world  clearly belong to one or the other of the two primate groups, called clades: Strepsirrhini and Haplorhini,” says Kenneth Rose, Ph.D., professor emeritus in the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine. “But many of the Gujarat bones show features that do not clearly belong to one clade or the other.”

According to Rose and lead author Rachel Dunn, Ph.D., an assistant professor of anatomy at Des Moines University, this suggests that the little primates represent a very early stage of primate evolution. That idea is counterintuitive, they say, because older primate fossils exist that show more specialized features, but they add that that situation is fairly common in the fossil record.

A simplified diagram showing evolutionary relationships among primates. NW, new world; OW, old world.

A simplified diagram showing evolutionary relationships among primates. NW, new world; OW, old world. Credit: Kenneth Rose, Johns Hopkins Medicine

At the beginning of the Eocene Epoch, about 56 million years ago, the world was warming, encouraging the dispersal of mammals between northern continents. The oldest known primate fossils found appeared around then in North America, Europe and northern Asia, but they can already be categorized as either adapoids or omomyids, the most primitive members of Strepsirrhini and Haplorhini, respectively. Adapoids were relatives of current day lemurs, lorises and bushbabies, while omomyids were more closely related to living tarsiers, monkeys and apes.

The newly discovered group of 25 tiny bones, all from somewhere below the neck of the animals, are younger — some 54.5 million years old — but considerably more primitive than the oldest known primate fossil, Teilhardina, which first appears in deposits at the beginning of the Eocene, almost 56 million years old. They are also more primitive than a relatively complete skeleton of the primate Archicebus, found recently in China and dated to about 55 million years ago.

Their analysis, Rose says, suggests the Gujarat primates are close descendants of the common ancestor that gave rise to the adapoids and omomyids found on the northern continents. But the Gujarat primates date back to a time when what is now India was a drifting land mass — isolated from the northern continents and inching its way toward southern Asia.

Fossilized bones found in a coal mine in Gujarat, India. A femur bone from Marcgodinotius, an adapoid, left; a femur bone from Vastanomys, an omomyid, right. U.S. quarter shown for size.

Fossilized bones found in a coal mine in Gujarat, India. A femur bone from Marcgodinotius, an adapoid, left; a femur bone from Vastanomys, an omomyid, right. U.S. quarter shown for size. Photo: Johns Hopkins Medicine

“These are the best preserved and most primitive bones we have from the first 5 million years of primate evolution, but there’s not enough evidence currently for us to figure out when these primates reached India or where they came from,” says Rose. “They are similar enough to the early primates found on the northern continents to indicate that their ancestors migrated between the northern continents and what is now India — but in which direction isn’t clear.”

Rose says there are several possible scenarios to explain what they’ve suggested, but all his team can say with high confidence now is that the tiny primates occupied equatorial India prior to its collision with Asia.

Even though the researchers don’t have enough bones to reconstruct a whole skeleton, the bones weren’t embedded in rock so they could be thoroughly examined from every angle, providing insights into the evolution of primate anatomy.

Their analysis is that the Gujarat primates were adapted for climbing the tall dipterocarp trees of ancient rainforests but were less specialized than present-day leaping lemurs or slow-climbing lorises. Their limbs and joints suggest more generalized climbing, as in present-day mouse lemurs and dwarf lemurs.

Because of such features, Rose and his colleagues aren’t sure which clade some of the bones belonged to, suggesting that they represent the most primitive primate anatomy known. But a few of the bones do show the beginnings of features that would later distinguish the clades, like deep grooves where the thigh bone connects to the knee, which helps animals like lemurs to leap. Rose believes it’s possible that differences in hind limb-based movement led to the primates’ divergence into two clades.

Previously discovered teeth and jaws of these tiny animals suggest that these primates were also close to mouse lemurs and dwarf lemurs in size, about 150 to 300 grams in weight, or 0.5 pounds. Considered together with their generalized anatomy, the small size of the Gujarat primates is likely another primitive trait, with future primates tending to increase in size.

“Considering everything together, we think the most likely scenario is that more primitive primates arrived in what is now India and retained their primitive, generalized skeleton, while their relatives on the northern continents continued to evolve,” says Rose. “Hopefully future skeleton finds will make it all clearer.”

Other authors of the report include Rajendra Rana of Garhwal University, India; Kishor Kumar of Wadia Institute of Himalayan Geology, India; Ashok Sahni of Panjab University, India; and Thierry Smith of the Royal Belgian Institute of Natural Sciences, Brussels.

This work was supported by grants from The Leakey Foundation and the National Geographic Society Committee for Research and Exploration.

Being Human: Born and Evolved to Run

Being Human blog marathon featured
Daniel Lieberman

Daniel Lieberman

Guest blogger Rebecca O’Neill (see bio below) shares her impressions of our July 28th installment of Being Human.

Running. Some people love it, getting in the zone and enjoying that “runner’s high.” Some people tolerate it as a necessary way to stay fit. Others, and I admit I’m in this camp, can’t see the appeal, unless they’re being chased by some terrifying beast or a swarm of bees….

However, there is no doubt that running is part of being human and has served us extremely well over the course of our evolution. I recently attended a Being Human lecture where Daniel Lieberman, professor of human evolutionary biology at Harvard University, explained why that was.

He started with the reason why running was so beneficial to us. Essentially, humans were able to hunt large prey (such as antelope) by outrunning them. It’s hard to believe, I know, but here’s how it works:  A human would start to chase an individual animal and track it when it sprints away. It would keep chasing the animal to the point where the animal would overheat. This is where humans’ ability to sweat is a huge advantage – we can cool ourselves while running. It gets to the point where the animal is dying of heat exhaustion, and the human can kill it simply by using a rock.

In fact, the human body has a whole host of traits, in addition to sweating, that enable us to run so well:  large gluteus (butt) muscles, long legs, short toes, lack of fur, our Achilles tendon (which gives our legs some of their spring) and many more.

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Treadmill demonstration

But it turns out that, despite all those beneficial physical attributes, many of us run inefficiently, which can cause injuries. During the event, Dan had two volunteers run on a treadmill on the stage to demonstrate the four criteria of efficient (and less painful) running:

  1. Posture – ideally landing with your hips, knees, and ankles bent a little bit so that you land under your center of gravity
  2. Cadence – ideally 170-180 steps per minute
  3. Foot strike – ideal position is on the ball of the foot, NOT the heel (which is higher impact can cause strain)
  4. Leg position – ideal position is landing with your tibia straight under you (many people “overstride,” with their leg too far in front)

So why do we run in today’s world? Most of us can buy our food – we don’t need to run down our prey. We certainly don’t need to escape predators. Why do we feel compelled to run such long distances? I wondered this as I watched my husband train for and complete his first half marathon. Bleeding nipples (yes, it’s true), aching muscles, shin splints, sore knees… what is the point, I wondered?

Part of it is the social connectivity. Dan pointed out that hundreds of millions of dollars are raised for charity through sponsorship for races globally. (The Leakey Foundation even had a team running the SF Marathon in July, raising thousands of dollars for field school scholarships!) His theory for why humans often train together in a group (or at least with a buddy), and why we have generated this phenomenon of giving back to the community, is that running evolved as an inherently social activity. Hunting was necessary for the whole community – pregnant and breastfeeding women and children needed feeding. We had to hunt together to be able to bring all the meat back home. I do admit, race days have a certain infectious positive energy and sense of connectivity with perfect strangers.

Another reason is the challenge – competing with yourself or others. (Dan said that a significant percentage of new race runners start because of a bet.) Part of it is that runner’s high (better than anything you can smoke, Dan attests). And of course, a huge part of it is the impressive health benefits. (Apparently runners live 20% longer than those who don’t exercise.)

Humans really are well crafted running machines – it’s a skill we should all be grateful for, regardless of whether we choose to run or watch from the sidelines.

About Rebecca O’Neill

RebeccaONeillI am a lifelong learner who is a passionate advocate for science and the human capacity for innovation. I have a bachelor’s degree in biology from Oxford University and a master’s degree in environmental science from Imperial College London. I have worked in a variety of nonprofit, media and business roles to promote environmental conservation. I currently live in Oakland, California, and work at SustainAbility, a hybrid think tank and strategic advisory firm working to catalyze business leadership on sustainability.

Charles Darwin has been a hero of mine for as long as I can remember. Evolution is one of the most important scientific theories that humans have discovered. I believe that The Leakey Foundation’s mission is a crucial one – we need to understand how we have evolved in order to make better decisions for ourselves, our society and our planet, both now and in the future.