I am very pleased to introduce this week’s guest, Professor Susana Carvalho, a primatologist and palaeoanthropologist at the University of Oxford! Susana is the head of Primate Models for Behavioural Evolution Lab at Oxford, and has directed the Paleo-Primate Project Gorongosa in Mozambique since 2015, leading an interdisciplinary team to carry out an unprecedented approach to understanding human origins and adaptations. She was also one of the main founders of the field of primate archaeology, studying the stone-tool use of non-human primates to understand the origins of cultural behaviour.
What are your research interests and your particular area of expertise?
I am very interested in early human evolution and fascinated by extant non-human primates. So far, I have focused my career studying the origins and evolution of technology, of bipedalism and currently I am interested in using extant primates to understand more about the evolution of predatory behaviours in hominins.
What originally drew you towards archaeology and human evolutionary studies?
My first degree was in archaeology and I worked for 7 years as an archaeologist before deciding to pursue an MSc in Human Evolution. I was always fascinated with exploration and discoveries. I dreamed of exploring inaccessible places, and truly loved history, how powerful and ground-breaking was the knowledge of our ancestors. I still think that is the case! I think I could have pursued multiple paths, as long as it would include some quest to explore something difficult and new. I grew up in Portugal, just after the dictatorship ended, during a time when David Attenborough documentaries started to expand our horizons about the natural world, and when Indiana Jones stirred an entire generation (it is true, no matter how shallow that idea now sounds!). I was also an avid reader, and loved travel stories, early explorers’ diaries, books on the pre-classics and classic societies, and basically any mysterious account of a faraway place. But, archaeology per se became, to some extent, a disillusionment. I realised I was much more interested in the lives of the humans behind the objects that we were digging. The first degree in Human Evolution in Portugal had recently opened in Coimbra and I decided to take my chances and apply. Somehow, I convinced Prof. Eugenia Cunha that I could do the degree despite my background in Humanities.
Why did you decide to do a PhD? Was your PhD experience what you had expected?
I did not decide to do a PhD and I had little intention of pursuing a career in academia! For my Masters, I ended up spending 6 months in Guinea Conakry to do my dissertation on the chaine operatoire of wild chimpanzee nut-cracking. I presented the results at a conference in Lisbon. I got an email from Bill McGrew a few days later asking me if I had considered doing a PhD in Cambridge…it is a long story, but I left my permanent job and my house and went to Cambridge to start my PhD in 2007. My experience was way beyond anything I could have imagined, even in my wildest dreams! I spent about 2 years in Guinea with the chimpanzees, punctuated by summers at the Koobi Fora Field School in Kenya, a 3-month fellowship in Japan, and so much more. It was a full immersion in everything I love to do, studying wild primates and exploring paleoanthropological sites, surrounded by an excellent group of colleagues and mentors, with the feeling that I was truly pushing the boundaries of something. Of course, retrospectively this all sounds great, but field work time was really hard and challenging, and personal life changed substantially during this period, so there were many adjustments and balls to keep in the air! I did feel that starting my PhD at an older age and my previous working experience may have buffered me against some of the stresses of multi-tasking and gave me a different perspective on the ‘relative’ importance of doing a PhD.
What were the findings from your PhD?
Overall, my discovery that the nut-cracking sites of chimpanzees matched, to a great extent, the strategies of use and exploitation of resources that had been described for early hominin sites. I reported for the first time the variation of tool types depending on the nut species targeted, the chimpanzee preference for reusing composite-tools, and the distribution and density of tools at chimpanzee nut-cracking sites. Of relevance were also the new chimpanzee nut-cracking sites I found in a very unexplored forest of Guinea (Diecké). In terms of technological-related behaviours, I found that chimpanzees increase their bipedal locomotion when transporting foods (nuts/papayas) that are valuable and unpredictable – that was a nice test of the carrying hypothesis done in the wild.
After your PhD, what positions have you held and on what kinds of projects?
I was a Junior Research Fellowship (JRF) at Clare Hall College, when I was still a PhD student at Cambridge, then briefly moved to a Post-doctoral position at Oxford on an ERC project named “Primate Archaeology”, and from there I moved to the USA where I was a post-doc at George Washington University, with Bernard Wood (that you just interviewed here!). This corresponds to a short period of less than 3 years, and the projects were all expansions of my Primate Archaeology original work, now thinking of applying the methods and principles to perishable tools, comparing sites, and taking the search for the ‘Older than the Oldowan’ seriously in eastern Africa.
You are one of the main founders of the field of primate archaeology: what exactly is primate archaeology? Why is it important for understanding human evolution?
Primate archaeology (unlike the archaeology of primates!) requires scientists trained in both fields. It aims to model the evolution of technological behaviour in the primate 0rder through a combination of methods to record behaviours and tools while they are being used and after use. It also addresses processes of site formation in vivo and focuses on strategies of exploitation of resources in the tool using areas. Technological evolution has been intrinsically linked to hominin evolution, but we have written our archaeology books without considering our primate living relatives, who can be excellent tool users and are leaving behind important archaeological sites. I can just name a few ‘micro-revolutions’ that have happened since 2007, directly related with the research developed by Primate Archaeologists: systematic surveys to find archaeological sites older than 2.6 Ma — and the acceptance that technology is not an exclusive of our genus; excavations of non-human primate sites that date back thousands of years; the discovery that monkeys unintentionally flake tools leaving those ‘archaeological’ signatures behind and, more recently, the discovery that perishable tools may be detected in the archaeological records via durable scarifications left in the raw material sourced – this will open an entire new branch within Primate Archaeology. I think the best and more impactful is still to come, as we start to accept that not all archaeological sites have to be human, and we do not have to continue restricted to behaviours encased in stone tools. I like to think we are picking up on an interdisciplinary spirit started by Louis Leakey. He was at the forefront of the first primatological field studies with great apes, while working in the East African Rift System (EARS) and focusing on studying past evidence of human evolution.
What current research projects are you working on? Where do you hope these will go in the future?
My main project now is the Paleo-Primate Project Gorongosa (PPPG). I like to think this is a truly interdisciplinary project in the EARS where researchers working with present and past data are collecting very different sets of information that will contribute to answer common questions about our origins. To do this you need a “Gorongosa”: a place with a modern mosaic of habitats and exceptional biodiversity, but also with fossil sites and with a diversity of contexts, including open air sites and caves. Gorongosa has it all and is located in a geographic zone that is critical to understand our biogeography. Within the PPPG, I co-direct excavations at our Miocene fossil sites, and I also conduct primatological research (with baboons), focusing on bipedalism and predatory behaviour. I continue to work in a series of projects within the Primate Archaeology framework, with ongoing collaborations in Guinea, Kenya, South Africa and Germany. I like to focus on the present, but I hope the Paleo-Primate Project will open novel ways of working and, most importantly, that I may see my Mozambican students leading our research and bringing prosperity to the region linked to the many discoveries we are making!
What is the Oxford-Gorongosa Paleo-Primate Field School? What have been your favourite memories from this project?
Our field school started in 2018 and is a collaboration between the University of Oxford and Gorongosa National Park. We provide training in primatology, paleoanthropology, archaeology, geology, speleology and ecology – and I think we may be the only field school covering all these disciplines. The field school is well integrated with the PPPG and students are able to develop their own UG or PG projects in connection to the project and mentored by a senior expert in one of the disciplines. I wanted this to be as inclusive as we can: we don’t charge tuition fees, and we help students applying to small grants to cover the expenses. 50% or more of the students are from Mozambique. I have too many wonderful memories, the day when we found our first fossil site, the day we found our first primate fossil, the first time we were able to follow baboons and actually see what they do, the nights around the campfire, that day when I found a lion on foot about 20 m from me…all the wonderful people that I have been able to meet and work with in Gorongosa – I have the best time there working with the best people.
What other projects are being conducted in the Primate Models for Behavioural Evolution Lab at the University of Oxford?
The lab has grown so much since 2016. We have almost 20 researchers at present. What is common to all is a shared interest in primates, the evolution of behaviour and human evolution. There are so many exciting projects, just to name a few: the archaeology of the perishable (Alejandra Pascual-Garrido), the ecology of stone tool use (Katarina Almeida-Warren), chimpanzee technological efficiency (Sophie Berdugo), behavioural responses to predation pressure (Philippa Hammond), cognition and culture in primate play (Alex Mielke), computer vision and machine learning approaches to finding fossil sites (João Coelho), our ancestors climate as a predictor of habitat change (Thomas Püschel). I recommend visiting our page and exploring all the ongoing research!
If you weren’t a primatologist/paleoanthropologist, what career would you choose?
A naturalist – it is sadly going extinct due to the pressures of this crazy world that does not allow scientists to take time to study their subjects in much depth. But I used to be a DJ in my free time (!) and I would have been happy working in the music world or cooking (Portuguese food!).