John Rowan: Addis Ababa #2—Gelada Anyone?

Heading to Guassa

Heading to Guassa

As hinted at in my last post, I’ve just returned from a weekend trip to Guassa, a cold but lush region of the Ethiopian highlands. While most of IHO’s research focuses on a single, highly specialized primate species (if you are reading this, you belong to that very species), I’ll use this blog post to provide a little background on one of our most interesting relatives. I spent the weekend in Guassa observing gelada baboons, and thanks to their passive nature, I was able to get up close and personal with one of Africa’s most amazing primates.

Highlands

The Ethiopian highlands are now sculpted by human activity, primarily agriculture.

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The “bleeding heart monkey” foraging for grasses

The gelada is among the rarest living primate species. The only place they are observable in the wild today is in a few of the cool and high altitude afro-alpine mountains of Ethiopia (although their close relatives were once more widely distributed across Africa, as will be discussed later). Their hair is generally a mix of brown, black, and gold, and their face is black with the exception of light pink eyelids. There is a reddish patch of skin on their chest and the tone varies depending on reproductive stage, dominance, and age (they are sometimes called the “bleeding heart monkey”). They are almost completely terrestrial and spend most of their time (up to 70 percent a day) feeding on the ground. Geladas are the only graminivorous, or grass-eating, primate, and 90 percent of their diet consists of high-protein grasses found at altitudes greater than 1700 meters. Unlike some hoofed mammals (like giraffids and bovids), geladas lack a specialized multi-chambered ruminant stomach and instead rely on bulk-feeding and extensive chewing with specialized cheek teeth to digest a diet so high in cellulose.

Geladas 2

Geladas live in social units consisting of a single breeding male (foreground) and up to twelve adult females (background)

The living gelada, Theropithecus gelada, is the single relictual (i.e., a remnant) member of a previously widespread group. The closest living relatives of Theropithecus are Papio (baboons) and Lophocebus (baboon-mangabeys), and Perelman and colleagues found that the last common ancestor of Theropithecus and Papio lived in Africa about four million years ago (mya) based on a well-resolved molecular phylogeny of living primates (a phylogeny is the depiction of evolutionary relationships among a group of organisms; “molecular” indicates the phylogeny was constructed using genetic data vs. anatomical or fossil data). The date of origination suggested by the genetic evidence compares favorably with the fossil evidence, as the earliest species of Theropithecus are found in Koobi Fora, Kenya at 3.94 mya and in the Middle Awash of Ethiopia at 3.9 mya.

Theropithecusbrumpti

Theropithecusbrumpti skull

There are many fossil species of Theropithecus, most of which were much larger than the living gelada. For example, T. oswaldi (2.5-0.25 mya) was a particularly large species, with males weighing over 85kg or 187 lbs in the more specialized Pleistocene representatives (males of the living gelada weigh 20kg or 44 lbs at most). The Hadar species of Theropithecus, T. darti, is almost certainly an early representative of what would eventually become the T. oswaldi lineage. Thus two small ancestors, T. darti and Australopithecus afarensis (Lucy’s species), living side by side at Hadar three million years ago would probably go on to give rise to two of the largest primate species, T. oswaldi and Homo sapiens (humans), respectively.

Interestingly, in another parallel with the human lineage, while Theropithecus initially evolved in Africa it is clear that the group subsequently dispersed into Eurasia during the Pleistocene, as fossils of Theropithecus have been found in Israel and India. Although, these two primates were not alone in their journey out of Africa, as their fellow travelers included species of Oryx (a large antelope), Hippopotamus (hippos), Kolpochoerus (a suid closely related to living African pigs), and Crocuta (spotted hyenas), all of which are of African origin like Theropithecus and Homo.

Okay—that’s enough digressing for now. There’s still more to do in my remaining two weeks in Addis.

John and Gelada

John and some close relatives

Until next time,

John

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John Rowan: Addis Ababa #1—The Token Paleontologist

Editor’s Note: John Rowan has previously posted from a field site in Ledi-Gareru and is now working with specimens at the National Museum in Addis Ababa. Just as primary field research is an important component of anthropological work, comparative analysis and lab research—which may not be as exotic or seemingly adventurous as living in a tent in the Afar—can be as satisfying and exciting to our students (and scientists)! So, here is a bit of a twist on “Notes from the Field.” I hope you enjoy it—I think you will!

Hello again!

After a short hiatus in Arizona, I have returned to Ethiopia. I arrived in Addis Ababa five days ago and the city has been buzzing with excitement as the African Union (AU) is celebrating their 50th anniversary at the AU headquarters in Addis this week. Heads of State from all over the continent and all over the world, including US Secretary of State John Kerry, have flown to Ethiopia’s capital to celebrate this historic moment. The traffic is worse than usual as police escorts cut through never-ending lines of cars and pedestrians.

Addis Ababa skyline

Addis Ababa skyline

For the next few weeks I’ll be living in Addis at the IHO house and working in the research collections at the Ethiopian National Museum. Along with AU festivities, the museum is also celebrating the return of Lucy, the famous female skeleton of Australopithecus afarensis, as she was returned to Ethiopia less than a month ago from her worldwide tour. Don Johanson, Lucy’s discoverer and IHO founding director, and Zeresenay Alemseged, former IHO postdoc and current IHO affiliate, flew to Addis to welcome back Ethiopia’s paleoanthropological gemstone. (Editor: To see a short (2 minute) Ethiopia television piece on “Lucy’s” return, click here; to see a longer piece (25 minutes), click here.)

Lab at the Ethiopian National Museum

Spreading out in the lab at the Ethiopian National Museum

While the AU and Lucy celebrations are a nice distraction, as the token paleontology student at IHO, I’ll be devoting most of my time here to the nonhominin fossils from Hadar and Ledi-Geraru. Primarily, I’ll be working on the “ungulates,” or hoofed mammals, including giraffes, hippos, suids (pigs), elephants, equids (horses), rhinos, and, in particular, bovids (antelope). In addition to IHO’s fossil sites, I’ll also be working with fossil bovids from the Omo and Middle Awash collections.

As noted above, I am particularly interested in the fossil record of African antelope. Bovids are an excellent group for macroevolutionary and paleoecological studies because they are geographically and temporally widespread, are abundant in Plio-Pleistocene fossil deposits, exhibit tribal dietary and habitat preferences, and are relatively specious, represented by roughly 140 extant species. But what does any of this have to do with human evolution? The data collected during my stay in Addis will help provide the broader ecological and environmental context of human evolution in Ethiopia, along with providing insights into the tempo and mode of evolutionary processes in a mammalian group that overlaps with the hominin lineage in body size, dietary and habitat preference, and geographic distribution. While it may seem bizarre to attempt to gain insights into evolutionary patterns of the human lineage through that of nonhuman mammals, several authors, primarily Elisabeth Vrba (Yale U.), have proposed that most origination and extinction events across mammalian groups have occurred in sync due to known climatic or tectonic changes over the last few million years in Africa (aptly termed the “turnover pulse” hypothesis). This hypothesis implies that hominins should fit to the general pattern of origination and extinction documented in other mammals throughout the African fossil record. Not surprisingly, this appears to be the case. For example, two of the most well-documented turnovers in African fauna occur about 2.8 mya and 1.8 mya, two dates that in human evolution correspond to the disappearance of Australopithecus afarensis (a species that had previously persisted for almost one million years) and the evolution of Homo erectus (an important grade shift in human evolution when many behavioral and anatomical characteristics of humans first evolve), respectively.

The arid-adapted Soemmerring's Gazelle, Nanger soemmerringi

The arid-adapted Soemmerring’s Gazelle, Nanger soemmerringi

Similarly, the commonness of bovids in the Plio-Pleistocene record provides us with insights into mammalian biogeography during this time and allows us to generate hypotheses about dispersal corridors and centers of endemism for rarer taxa that are less common in the fossil record, including hominins. Also, bovids are excellent tools for reconstructing early hominin habitats since they are characterized by distinct habitat preferences based on tribe (tribe is a low taxonomic level of organization—it groups similar animals together below the level of subfamily or family). For example, the recovery of reduncin bovids (e.g., kobs) at fossil sites indicate the presence of well-watered habitats and some waterlogged grassland, while the recovery of aepycerotins (impala) indicate ecotonal habitats where savannah grasses border woodland and more densely vegetated landscapes. The fossil record of antelope provides many other useful tools that help elucidate the evolutionary, ecological, and environmental context of human evolution, but for the sake of brevity this is all that I’ll discuss (for now).

One of Africa's largest bovids, the African Buffalo Syncerus caffer

One of Africa’s largest bovids, the African Buffalo Syncerus caffer

So, that’s all for now—my next post should be coming soon and I’ll talk about my trip to the Ethiopian Highlands, from which I just returned, where we observed some of the rarest monkeys in the world—gelada baboons.

Cheers,

John

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John Rowan: Ledi-Gareru #2—Through Kenya and Tanzania to Ethiopia

Editor’s Note: John has extensive research and field experience. Below is a bit of his story and a little more on what is happening in Ethiopia on this trip.

Issa woman and baby

Issa woman and baby from Tanzania travels.

Last summer, I was invited to participate in the Koobi Fora Field School operated by Rutgers University, George Washington University, and the National Museums of Kenya. On the Laikipai Plateau, I helped lecture on paleoecology with Dr. René Bobe. René and I used the modern Kenyan ecosystem to teach students about taphonomic processes, preservation biases in the fossil record, how to calculate species diversity and abundance from fragmentary remains, and how to identify scraps of bone to the family level. From there, the field school moved north to the eastern shores of Lake Turkana, an area famous for its hominin-rich fossil localities.

teaching in Kenya w Bobe

Teaching in Kenya with Dr. Rene Bobe

At Koobi Fora Base Camp, I lectured on vertebrate paleontology and evolution, exposing anthropologically centered students to a whirlwind tour of 550 million years of vertebrate history. After a week of lecturing, we moved two hours further north along the lake to Ileret, a Pleistocene locality famous for its preservation of Homo erectus footprints. In this last leg of the field school, I assisted Dr. Brian Richmond with the uncovering of more H.erectus footprint layers and the collection of new hominin fossils. With Dr. Kay Behrensmeyer, I helped direct the paleontology team that will provide the ecological context for the environment in which early Homo erectus was living in 1.5 mya.

 

cataloging fossils

Cataloging fossils at Ledi-Gareru 2013

In fall 2012, I entered the evolutionary anthropology PhD program at Arizona State University as Dr. Kaye Reed’s student. Since arriving at ASU, I have directed my research towards understanding the evolution of terrestrial mammal communities in Africa during the latest Miocene (~ 10 to 5 mya) and Pliocene (~ 5 to 2.6 mya). This spatiotemporal setting is important because various climatic factors and faunal migrations into and out of Africa “set the stage” that human evolution eventually played out on (molecular and fossil data suggest that Hominini originated ~ 7 mya). Of all the various fossil localities, the Afar depression and Turkana Basin are perhaps the two most important regions within the entirety of Africa for piecing together the human story. So, my current research interests are in the alpha taxonomy (species recognition and differentiation), phylogeny (evolutionary relationships), and biogeography (distribution) of East African mammals from the Turkana Basin of Kenya and southern Ethiopia and the Afar region of Ethiopia. Through this research I will be able to help define the broader environmental context of human origins in Africa.

chalachew and john

John with Ethiopian-born IHO doctoral student Chalachew Seyoum at the Ledi-Gareru site

Now, back to today—since my last post, we’ve uncovered a lot more fossils, the geologists and archaeologists have arrived (finally), and we’ve entered the home stretch for this field season. In the next few days I’ll shoot over another post on what’s actually going on in camp—things have gotten hectic around here as the days dwindle. I have lots of exciting stories to tell, but for now, I have to get back to surveying for fossils!

Cheers!

John

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John Rowan: Ledi-Geraru, Hadar, Ethiopia

Note from the Editor: This begins the newest entry from our “Notes from the Field” series, this time written by one of IHO’s newest doctoral students, John Rowan. In upcoming entries, you will hear more about John’s research interests. I am so interested to hear about what IHO researchers and the international team of scientists are doing in Ledi-Geraru—and I am happy to bring you that news from John.

Greetings from the Afar of Ethiopia—this entry comes from our campsite in the arid scrubland of the Ledi-Geraru research area.

IMG_2552

Welcome to Hadar!

I arrived in Addis Ababa in late December and spent a few weeks working in the National Museum of Ethiopia on Pliocene faunal collections with IHO professor Kaye Reed. The museum was lively as preeminent scientists like Terry Harrison and Yohannes Haile-Selassie were working in the research collections or preparing to head out into the field.

Lucy site plaque

John in front of the “Lucy” site plaque

The 2013 field season for the Ledi-Geraru Research Project kicked off on January 9 as we packed up and made the eight-hour trek from Addis Ababa to the Afar. Our team here includes Kaye Reed (IHO/ASU), Ramon Arrowsmith (ASU), Brian Villmoare (George Washington University), David Feary (ASU), three ASU PhD students (Erin DiMaggio, Chalachew Seyoum, and Dominique Garello), and local Afar workers (including the famous Omar Abdullah). The rest of our crew arrives at the end of the month and includes Chris Campisano (IHO/ASU), Lars Werdelin (Swedish Museum of Natural History), and Dave Braun (George Washington University). Every participant forms a different piece of a larger puzzle as we try to collectively reconstruct human evolution in East Africa using lines of evidence from geology, paleontology, and archaeology.

Our current focus is to investigate new fossiliferous exposures that should help fill a significant gap in our understanding of human evolution in East Africa. In the Afar, the Hadar Formation ranges from 3.5mya—2.95mya and is overlain by the Busidima Formation from 2.7mya—160,000ybp; however, sediments ranging from 2.95—2.7mya are missing from the sequence due to an unconformity. For paleoanthropologists, this small slice of time is of great importance because it may be the time when our genus, Homo, originates. To throw light on the origin of Homo, the Ledi-Geraru Research Project was initiated by the late Charlie Lockwood, Kaye Reed, and Ramon Arrowsmith in 2002 as an attempt to clarify the transition from Australopithecus and the emergence of Paranthropus (a bizarre evolutionary off-shoot of robust hominins) and Homo. Along with the earliest members of our own genus, the first stone tools may have appeared during this time period.

IMG_2548

New discoveries!

The field is always an exciting place of discovery—so far we’ve already deduced that the animals we’re finding in the Ledi-Geraru research area are very different from those at Hadar. In the Hadar Formation, the uppermost deposits demonstrate a general trend towards a more open and arid environment—a change that is in sync with increasing robusticity in Australopithecus afarensis (Lucy’s species). But, as noted above, after 2.95mya, we’re not sure what became of Au. afarensis or the animals with which it shared the landscape with. Ledi-Geraru is showing us that there may have been ecological changes in the Afar around 2.8mya similar to those documented in the Omo-Turkana Basin of northern Kenya and southern Ethiopia. We’ve uncovered new monkeys, bovids, hippos, and other mammalian taxa that may represent immigrants into the Afar from other areas or new and unique species that have evolved from the older Hadar fauna.

That’s all for now—more to come soon!

Cheers!
John

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Thierra Nalley: Another View from the Field #5—Paris, France

Bonjour!

Greetings from Paris! I had two work goals this week. The first was to fill in a few gaps in my extant primate sample with a small number of difficult-to-find primate species, particularly certain lemurs such as sifakas (Propithecus diadema) and indris (Indri indri), at the Museum National d’Histoire Naturelle. Unexpectedly, and continuing the theme of community from previous posts, I ran into another IHO graduate student here in the comparative collection—Emily Hallett, a PhD student of Dr. Curtis Marean. She is preparing for her six-month data collection trip at an early modern human site in Morocco. Did I mention “we” are everywhere? The phrase “My name is IHO, we are many” comes to mind.

Anyway, the comparatiThierra Paris fig 1ve collection is located in a large, square room with an open ceiling full of skylights. The walls are lined with wooden drawers from floor to ceiling, complete with a twisting staircase to reach the upper loft. In addition to primates, other animal groups are also housed here: bats, birds, and the occasional lion. The natural light and openness of the room are worth mentioning, because for the most part, the osteological collections I have been working in have kept me in small, windowless rooms with florescent bulbs. This area was a nice breath of fresh air.

My second goal was tThierra Nalley fig 2 Pariso measure two Neandertal specimens for my fossil sample from the collections of the Musée de l’Homme. The Kebara 2 skeleton includes a complete set of cervical vertebrae (1–7) and represents a more eastern population of Neandertals, discovered at a site in Israel. The more well-known La Ferrassie skeleton also has a complete set of cervical vertebrae and represents the classic Western European Neandertals found at a site here in France. Unfortunately, as a graduate student, I am not able to hold and measure the fossil specimens. Who can handle fossil material varies across collections and institutions, and this particular collection is one of the few with such strict policies. Thus my Neandertal measurements were acquired from high-quality casts of the specimens. It is perhaps not ideal, but it will work for my purposes.

My stay in Paris has also allowed me to practice my limited French, as the researchers and students I came into contact with varied considerably in their English-speaking abilities. The vast majority spoke better English than my French, so I think communication was pretty successful. I am headed back to the States at the beginning of July and will be spending three weeks in NYC at the American Museum of Natural History. Let’s see if I run into any ASU/IHO folks there!

Au revoir,

Thierra

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Thierra Nalley: Another View from the Field #4—Nairobi, Kenya

Greetings from Kenya!

This is my first time to Nairobi, and I’m sorry to be spending only three nights here in the city. I have little time but to work at the museum during the day and watch rugby cup matches on the TV at night while I format data. Ironically, I am spending the least amount of time at this museum, but it took the most effort, paperwork, and money to gain access to the Australopithecus (Paranthropus) boisei and Homo erectus specimens housed here.

TN Kenya 1Serendipitously, I was able to add a fun bonus to my fossil sample with a few recently published Miocene hominoid specimens that date to about 15 million years ago (mya). The Japanese researchers who discovered and described Nacholapithecus kerioi were very gracious, allowing me to measure the fossil vertebrae before they were even moved from their “unpublished” field bags to the “published” shelving in the museum fossil vault.

TN Kenya 2This step in fossil curation is currently what Dr. Kimbel is doing with some newly published Hadar material in Addis Ababa. I am very excited to add this particular fossil species to my sample because it may represent a “transitional” form; its morphology suggests some of the earliest suspensory adaptations in the hominoid (apes and humans) fossil record. If the locomotor TN Kenya 3hypotheses in my dissertation are supported, than I can apply them to ancient hominoids such as Nacholapithecus kerioi and help us understand when suspensory locomotion evolved in the hominoid lineage. This is an important question to many paleoanthropologists because it would help establish if suspensory locomotion evolved independently in the orangutan, gorilla, and chimpanzee lineages or if it is a shared trait of all hominoid ancestors (including hominins). Understanding when suspensory locomotion evolved lets researchers know if it should be incorporated into the context of our own species’ evolution.

TN Kenya 4My hotel is a five-minute walk to the museum and the hotel grounds are surrounded by deceptively lush gardens. Once outside the hotel compound, however, the quick stroll to the museum is a drastic shift from decadence to a developing urban center. It is a relatively safe neighborhood with a large amount of foot traffic to the nearby university. But I do not have a picture illustrating the change in scenery, as I did not want to push my luck taking out a camera. Carrying the 3D digitizer in a hard-cased rollaway is already enough “stuff” to draw attention to myself.

I leave for Paris tomorrow, and I am looking forward to staying in a rented flat where I can walk around a bit more when I am not at the museum. Not to say that I do not love working in and visiting Africa. It of course comes with its own set of special travel issues, especially for a woman travelling alone; but when I can see Mt. Kilimanjaro poking through the clouds from my airplane window and hold a 15 mya fossil vertebra in my hand the following day, well, experiences such as these make working in Africa pretty wonderful.

Thierra

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Thierra Nalley: Another View from the Field #3—South Africa

Hello!

As I mentioned in my previous post, my next stop is in lovely South Africa (SA), which is currently in the grips of winter and quite chilly. The goal of this trip is to visit the Ditsong (formerly known as the Transvaal) Museum of Natural History. Some of the earliest discovered and most famous hominins are from the South African sites Sterkfontein, Swartkrans, and Kromdraai and are stored at the Ditsong Museum. But before I get to business, the theme of community continues as I meet up with ASU/IHO alums Drs. Laura Bidner and Amy Rector–Verrelli for a few days of adventure. Dr. Rector-Verrelli is a paleoecologist and is currently faculty at Virginia Commonwealth University. She is running a South African summer program for a group of undergraduate students. Dr. Bidner is a primatologist and has a postdoctoral position at the University of Fort Hare here in SA. Since we were all so close at the same time, Dr. Rector-Verrelli invited Dr. Bidner and myself to accompany her and her students to Kruger National Park to see some of Africa’s famous wildlife and perhaps give the students different perspectives in biological anthropology. And holy crap, the day drives through the park were successful—sometimes also most too successful (rhinos are especially grouchy when there are babies in the herd). Even our camp was alive with wildlife. There were bushbabies and fruit bats in the trees at night and vervet monkeys and warthogs in the mornings, both attempting to get into the trash. All in all it was very exciting and fun to experience the park with friends and colleagues.

animals

I left Dr. Rector-Verrelli’s group as they were headed to Capetown and to later visit the IHO crew currently excavating at Mossel Bay. Dr. Bidner traveled back to her baboon troop in the mountains of Hogsback, and I got a ride to Pretoria and the Ditsong Museum. The museum is currently being renovated, so its full glory is unfortunately under dust and scaffolding, but the sense of history here cannot be ignored. The hominin vault, also known as “The Broom Room,” is filled with tall cases made of glass and wood, the shelves are lined with red velvet, and this small room has a distinct Old-World feel. And as I mentioned, some of the most famous hominin fossils are stored here as well as the relics of their discoverers. Dr. Robert Broom was an advocate of human origins in Africa (when at the time the field was also considering Asia) and the discovery of the Mrs. Ples skull (STS 5) aided in the paradigm shift started by Raymond Dart and his description of the South African Taung child fossil in 1924. Another pioneer, Dr. C.K. (Bob) Brain, is also present, whose continued work at Swartkrans until the late 1980s helped to develop the modern day study of taphonomy (how organic remains transition to fossils).

Dr. BroomDr. CK (Bob) Brain labThe museum staff is lovely, and I am setup at a desk surrounded by skeletons of African animals. There only a few Australopithecus (Paranthropus) robustus cervical vertebrae, but they are nicely preserved. Australopithecus africanus has a frustratingly large number of vertebrae, but alas, none are from the cervical spine. I chose to get them out anyway, just to see the famous STS 14 skeleton and of course take notes on the vertebral morphology.

craniaworkstation in Ditsong Museum

That is it for this trip! I have a brief stop in Nairobi, Kenya before I am off to Paris, France. The whirlwind museum tour continues!

Take care,

Thierra

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