Sebastián Ramírez Amaya is a PhD Candidate in Evolutionary Anthropology at the School of Human Evolution and Social Change at Arizona State University. He received a Leakey Foundation research grant in 2020 for his project entitled “Male-female social relationships in chimpanzees and the evolution of pair-bonding in humans.”
Q: Do you remember when you first became interested in science?
It was during my undergrad at Universidad de Los Andes in Colombia. As biology students, we took a ten-day-long field trip at the end of every semester. That is where my love for fieldwork started. During one of those field trips in 2011, I had to follow a group of wild woolly monkeys for two days in a beautiful high Andean wet forest. Since then, and until today, my work and research revolve around following wild primates in their natural habitats.
I am currently working on my PhD dissertation, “Male-female social relationships in chimpanzees and the evolution of pair-bonding in humans” under the supervision of Dr. Kevin Langergraber.
Q: What question are you trying to answer with your Leakey Foundation-supported research?
To date, long-term pair bonding in the context of multi-male, multi-female groups in humans is still considered to be an evolutionary mystery. There is no consensus on how pair-bonding first evolved in humans, nor on the evolutionary pressures that made it beneficial to humans. My dissertation examines the social and mating system of our closest living relative, the chimpanzee, in order to assess whether the mating system of humans and chimpanzees are as exceptionally dissimilar, or more similar to each other, than previous research has suggested. My approach is grounded in an evolutionary framework, which suggests that closely related species of primates should have more similar social and mating systems than distantly related species.
The first goal of my dissertation is to determine whether, as with patterns of party association, male-female chimpanzee dyads at Ngogo also show differentiated patterns of affiliation and aggression (i.e., affiliative and aggressive relationships).
The second goal of this study is to determine the extent to which the affiliative and aggressive components of male-female relationships predict their reproducing together. In addition to novel behavioral measures and genetic data, the third goal of this research is to explore the physiological stress level of females, as well as the individual stress-hormone reactivity of females that form strong social relationships with adult males and those who do not.
Q: What excites you most about the work you do?
The most exciting part of my work is the fieldwork component. Being in the forest for an extended period of time following primates is what triggers my curiosity and ultimately allows me to mature and answer my research questions. On a personal note, fieldwork allows me to challenge myself every day in very unexpected circumstances.
Q: What are some of the challenges of your work?
The biggest challenge we face as field scientists is to learn from and involve local people in our work. Even if it is not directly related to the scientific nature of our research, cultural exchange and opportunities to interact with the local population is beneficial for both parties. Especially when considering what we as scientists leave behind in each of the places we go to collect data for extended periods of time.
Q: What else are you working on?
Along with my dissertation I am answering similar questions on the sociality and behavior of male and female spider monkeys in collaboration with Dr. Anthony Di Fiore and Dr. Andrés Link. I spent two years following these primates in the wild. It has been remarkably interesting to note similarities and differences between my research experiences working with spider monkeys and chimpanzees. Despite being distantly related species, they have very similar social dynamics. This is interesting on its own, but can also be useful for answering questions about the evolution and adaptive benefits of sociality among primates that live in multimale-multifemale groups of primates.