ECR Spotlight – Grégoire Boulinguez-Ambroise Free

Grégoire Boulinguez-Ambroise

How did you become interested in biology?

I have always loved exploring the trails around the house, watching plants grow in cracks in the walls, insects climbing the tortuous bark of trees, and all the aquatic life in ponds. Growing up, I developed an interest in the plant world specifically, I needed to know all of their names and write them down in my herbarium. But along with its wonders, life soon started to show some of its difficult realities too, and after the death of my grandma, I became convinced of the need to find new cures, and the idea that distant, unexplored jungles might reveal plants with medicinal properties. It was later on, after breaking some fingers trying to play sport in high school – like many others, I guess – that I picked up a newspaper on the table in a doctor's waiting room. An article promoted the research of a primatologist studying the use of plants by chimpanzee as pharmacopoeia, and how we could learn from them. It was at this point that I fell into the spiral of the primate world – from observing plants growing in the meadows and ruins to sitting in front of the windows of the menagerie at the museum, observing monkeys for hours. It is at the museum too, that I met a very special primate, a human one – Dr E. Pouydebat – who would introduce me to my future field of research: grasping, a key feature of primate evolution. Being a violinist on the side, I have always been impressed by what our fingers can do. From the earliest age and recruiting both strong and delicate movements, they allow us to see even with our eyes closed, to feel, interact with and even shape our environment.

Describe your scientific journey and your current research focus

My scientific journey started after high school with two years of intensive training in biology, mathematics, chemistry, physics and geology that would ultimately allow me to enter one of the French Great Schools. In parallel, I had the opportunity to do a research Master’s and become specialized in functional and evolutionary ecology. As part of this training, I carried out my first own research project during an internship with Dr Bales at the California National Primate Center. I met the titi monkeys – a.k.a. the ‘hippie’ monkeys – and studied altruistic behaviors within pair-mates, in addition to participating in diverse lab activities. I was 21, and the immensity of the American landscapes stood before me, not only enhancing the call of the wild, but also confirming my calling to do research. During my second Master’s internship, at the National Museum of Natural History (Paris), I started to investigate grasping in primates. This is when I started developing an ontogenetic approach, carrying out integrative studies, focusing not only on behavior but also combining morphology and performance. I wrote my own PhD project – as a follow-up to my Master's research – benefiting from the supervision and mentorship of two passionate and kind-hearted researchers, Drs Pouydebat and Meguerditchian. Their most powerful teaching has probably been to always preserve one's capacity for wonder, as it is a driving force for creativity and innovation. My PhD research focused on the acquisition of grasping abilities across development, considering this function in the different contexts in which it is involved: feeding, social interactions and locomotion. Using force plates to measure grasping performance, I felt the need to explore the biomechanical aspect of locomotion further to better understand its origins in primates. This is what I do now for my postdoctoral research, investigating biomechanical strategies of leaping performance with Dr Young, or further testing hypotheses on primate grasping evolution with Dr D. Schmitt. This journey has been filled with encounters with people – students, mentors, animal keepers – who became friends, and have helped me grow, not only in terms of scientific maturity but also on a personal level. I am forever grateful!

How would you explain the main findings of your paper to a member of the public?

Jumping is a behavior that proves crucial in a wide range of activities including locomotion, resource acquisition, predator avoidance or even courtship displays.

In primates, paleontological evidence suggests selection for enhanced jumping ability during their early evolution. However, while fossils can reveal anatomical transformations (variation in bony features) during primate origins, they currently provide only imprecise clues about behavioral capacity. To further understand how a fossil species was moving, and exhibiting what level of performance, we need to find robustly supported correlations between morphology and performance. Such associations can be explored in extant species and then used when interpreting the fossil record.

Here, we investigated jumping performance in three callitrichine monkeys falling along a continuum of jumping propensity: Callimico (high propensity), Saguinus (intermediate) and Callithrix (relatively low). We designed an original apparatus – a custom-built tower instrumented with force plates – that could be placed in the animals' enclosures at the Cleveland Metroparks Zoo (OH, USA). Individuals performed vertical jumps to perches of increasing height within this ‘jump tower’. Force platform analyses generated biomechanical data on maximal jumping performance that we coupled with micro-CT data quantifying bony features thought to reflect jumping ability.

According to the law of physics, the vertical height achieved during a jump is determined by the velocity reached at take-off. An animal has two strategies to increase take-off velocity: (1) push forcefully against the launching substrate, or (2) increase the push-off distance, typically by fully extending the hindlimb joints.

We found that the different levels of maximal performance between species paralleled the established gradients of jumping propensity. Both biomechanical analysis of the determinants of jumping performance and analysis of bony hindlimb morphology highlighted different mechanical strategies among taxa. For instance, Callimico, which has relatively long hindlimbs, followed a strategy of fully extending of the limbs to maximize push-off distance, rather than force production. In contrast, relatively shorter-limbed Callithrix depended mostly on relatively high push-off forces. Overall, these results suggest that leaping performance is at least partially associated with correlated anatomical and behavioral adaptations, suggesting the possibility of better inferring performance from the fossil record.

Why did you choose JEB to publish your paper?

We think our research was especially well suited for JEB, which is the leading journal in comparative animal biomechanics. First of all, we present an original custom-built apparatus that allows us to collect biomechanical data on jumping performance, even the maximal level of jumping performance. This apparatus can be placed in the animals' enclosures in zoos and can be moved easily from one enclosure to another, allowing us to collect data on several species for a comparative study. The protocol we describe does not require interactions with the animals or training of the animals, promoting the display of a more natural behavior. We are confident it will be of interest for the audience of JEB, working on jumping biomechanics or, more largely, developing experimental setups for research carried out in zoos. Our research is also comparative, exploring jumping biomechanics in several primate species, which allowed us to identify the use of different biomechanical strategies for jumping partly associated with morphological features.

What is your favourite animal, and why?

I have worked with more than 10 primate species, squirrels, tree shrews, even elephants: I loved all of them. They made my dream come true. If I really have to pick one, I would say the aye-aye (Daubentonia madagascariensis). In my opinion, this very unique species of Strepsirrhines (suborder of primates, including the lemurs) is a jewel of evolution. Aye-ayes present some incredible anatomical features. They have giant front teeth roots (incisors) that support most of their jaw, and are continually growing. They have big ears and a very long fluffy tail. Their middle finger is very thin and elongated and can move in every direction – which is the perfect tool to reach insects and larvae hiding in the bark of trees, or to delicately make a hole at the base of an egg to swallow its contents. A recent study even described a very special use for this finger: they can push it deep into their sinuses to clean them out! They are very friendly and young ones jump around like puppies. Being nocturnal, they are not very well known by the general public, as they are difficult to see in zoos. But meeting an aye-aye can be life-changing, so look out for them!

Do you have a top tip for others just starting out at your career stage?

Research is becoming more and more interdisciplinary – and this is a great thing. However, it is hard to master all the disciplines, even one, and probably impossible. The time of medieval scholars – like Faust – is over, our knowledge is too vast. Collaboration with other scientists, and also non-scientists, is the key to learn more and become better at grasping the big picture of a research project, and identifying all the parameters that can be involved. Keep an open mind and be open to collaboration. Being a researcher is to grow perpetually. There is so much to learn from others. Every collaboration, every piece of feedback is priceless.

What is one thing about you that others might find surprising?

Ever since I was little, I have loved LEGO. I build a lot of them and – at this point – my living room is becoming a LEGO museum. It might sound a bit excessive, but these little colorful bricks make me very happy. You can follow the instructions for a specific set, appreciate the beauty of how well it has been engineered and create a little universe collecting different sets. Or, you can also create your universe from scratch using loose bricks. With my partner we have recreated our local farmers' market, which looks awesome. You have got to keep your childlike spirit; it is very important. Especially in research, you have to observe, be curious, be amazed and tell good stories. Keeping your imagination at its highest level is fundamental to coming up with ideas – what will be my next research project? – and creating innovative devices, apparatus and protocols to answer your questions. This is especially true in experimental biology!