Tomàs Marquès Bonet: “There are still people who pay $100,000 to have a chimpanzee at home.”

That life is full of coincidences and that it's about knowing how to seize them is something Tomàs Marquès Bonet (Barcelona, ​​1975), one of the world's leading experts in primate genomics and evolution, knows well. Although he wanted to dedicate himself to studying bats and Pyrenean frogs, he ended up at IBM performing banking transactions and learning to program. A few years later, life presented him with an opportunity to return to science, which he seized by writing a computational thesis at Pompeu Fabra University (UPF) comparing humans and chimpanzees. And so, it all began again. Since then, Marquès, a professor at UPF and ICREA researcher, and head of the comparative genomics group at the Institute of Evolutionary Biology (IBE UPF-CSIC), has dedicated himself to the molecular study of primates to learn about humans as a species. He argues that the genomes of our closest evolutionary relatives are key to understanding human biology. Also to combat the illegal trafficking of these animals and help their conservation.

For his scientific advances, in March he was appointed a corresponding member of the Royal Academy of Sciences (RAC). And now he has just been awarded the prestigious Ramón y Cajal Medal, which the RAC grants every two years to researchers under 50 who have made significant contributions in any area of ​​science.

Congratulations.

— Thank you! I'm very happy. It's quite an achievement to receive this medal for doing evolutionary biology and studying primates. [Laughs]

He's spent 20 years trying to decipher what makes us human. Has he removed the framework?

— My research focuses on understanding what separates the human lineage from primate lineages. To do this, it's first necessary to know what the genetic changes are between them in order to then understand their consequences. I'm still in this phase. In 2023 we published in Science the genome of 200-odd primate species...

It was the first time that a high-impact scientific journal had dedicated a special issue to research conducted in Spain..

— ...and we took the mutations that we previously thought were exclusive to our lineage and compared them with those of the great apes. We reduced by almost half the mutations we thought were specific to humans, because we found them in other primates.

For example?

— The foxp2 gene, behind speech. We've identified it in other primates, although this doesn't mean they have the same vocal structure and can speak. Or that they lack neuronal development, like the new gene. Contrary to what we thought, these traits aren't exclusive to humans; we share them. Once we've finished defining the genetic structure—that is, the specific mutations that separate humans and primates—we can begin to link characteristics that define us as a species, such as having a large brain or walking upright. And then we'll be able to identify the genetic basis of traits that are specifically human.

Is having a reference genome for each primate species enough?

— Nothing. Ever since we started primate studies in 2012, I've shied away from the idea of ​​creating a reference genome for many species. I've always worked from a population perspective because I'm more interested in genetic diversity than in a single genome, especially in primates, because there are so many species and subspecies. It's essential to have maximum representation of the variability within the species and not focus on individuals.

The same thing happens with humans. A recent study by the Centre for Genomic Regulation He argued that the human reference genome being used was biased and did not represent humanity.

— Exactly. In fact, when the first human genome was sequenced in the 1980s, it was thought to be the key to all secrets, and a mix of humans from different cell lines was created for ethical reasons, which was all well and good, but it wasn't realistic.

To perform population genomics that reflect the diversity of primate species and subspecies, you need access to many samples of these animals. How do you do that?

— Much of the success of my research is thanks to my collaborators. I've always been clear that everyone should be treated equally, and therefore, all the people who have provided me with samples are co-authors of my articles, which can include up to 100 people. These are people who may have been in the Amazon, sleeping in hammocks in the rain, to take a sample I was missing. I can't have the advantage of being listed as the sole author simply for having performed the molecular analysis on those samples.

That's not usually the case in science...

— It's part of my vision of what science, at least primatology, should be: a global perspective of international collaboration. Word has spread that I'm fair in the way I do science, and that has brought me more samples and opened the door to the possibility of collaborating with people in the countries where the primates live. Before I had a network of collaborators, I approached primatologists who had spent their entire lives in the field, studying primates, and convinced them to work together. I was very fortunate that everyone I approached said yes. They made their lifetime collections of specimens available to me. And this has been crucial because without them, it would have taken me decades to carry out a project. I like to think, and it makes me proud, that my lab is pioneering a new way of doing cross-border collaborations.

Does it only collaborate with samples?

— We're increasingly committed to sequencing locally, promoting local knowledge, and integrating local students into our teams. Right now, I have a student from Congo in my lab, training with us and working with their samples. She'll return later, and the challenge is for her to train other students there so they can explore the molecular genetics of biodiversity in the Congo region. Although I have many concerns, because these countries ultimately lack infrastructure. No matter how much I go there to train them in genetics, how will they do it if they don't have the equipment? They're not really playing on a level playing field. These are countries that need a scientific investment. They have the biodiversity; we exploit it.

Is it no longer the case, like 20 or 30 years ago, to take a plane and come back with a backpack full of samples?

— I want to believe that this is unthinkable today. Or at least I hope it happens less and less. We have a responsibility to show future generations that research projects cannot be carried out without local people, without the transfer of knowledge between developed and developing countries. At least in my lab, we do what we can to make things work more fairly.

What samples does he work with?

— With blood and tissue. We never capture animals; we're opportunistic: if someone finds the carcass of a dead chimpanzee in the jungle, they take a muscle biopsy and send it to us. In the lab, we often receive carcasses or animal samples, some even rotten. Sometimes we also receive blood from veterinary tests done to assess the animals' health. And now we've also started working with feces. One of the major innovations in my lab has been developing methodologies and protocols to extract as much DNA as possible from the host. When feces travel through the intestinal tract, they carry a few epithelial cells, and we try to recover as many as we can. This has allowed us to open the door to population genomics; we can't sequence entire genomes, only partial ones, but we can do many because it's so easy to find and recover feces.

Use the feces to combat the illegal trafficking of apes.

— I was often asked if I could identify an animal's origin from a blood sample. That was impossible for a number of reasons. But with feces, we know the GPS coordinates of where they were found, and once analyzed, we've been able to identify that primates are genetically stratified: a chimpanzee, for example, from northern Gabon is different from one from the south of that country. The precision is such that we can even pinpoint which national park they came from. In this project, we've worked with a United Nations group and with African sanctuaries that receive confiscated animals. If all goes well, we expect to have the first atlas of the origins of the illegal trafficking of great apes, especially chimpanzees, before the summer of 2026.

Will it help stop the capture of these primates?

— We mustn't be naive: when we reveal the origins of captured chimpanzees, that illegal trafficking route will simply disappear, and a new one will emerge. The solution can't be just building barriers. The key is education, as has been demonstrated with mountain gorillas: we've worked with local communities to show them that they can generate much greater returns by caring for the gorillas and attracting visitors who pay substantial sums to see them. And that the benefits they'll reap are long-term. Now, with the United Nations, once we identify the areas in Africa from which the most animals are taken, we will begin implementing education and conservation programs to empower local communities to protect them.

Through tourism?

— We will create a good system to attract tourists, so people pay to see chimpanzees and gorillas, and that money goes back into local communities. Ultimately, it's a socioeconomic problem: people who are hungry find a way to make money through animal trafficking. We hope that from here, from Barcelona, ​​we can help change this. We already have almost 500 confiscated chimpanzee specimens.

Are they the ones who suffer the most from traffic?

— Yes, because it's the smallest of the great apes and because there are more of them. Also, traffickers often target the young. There's a terrible statistic: for every infant captured, they kill 10 adults. Every year, hundreds are taken from Africa to be sold to illegal zoos. In the United States and Europe, there are no zoos that still take animals from the wild, but there are in Asia. And there are still people who want to keep wild animals at home and are willing to pay up to $100,000 for one.

How can chimpanzee genetics contribute to the search for human biomedicine?

— Humans are also primates, and we share with this group of species similar genetics, physiology, chemistry, cell biology, and therefore, similar diseases. Serious illnesses are usually caused by rare mutations. We can now read genomes, but we still don't understand what the changes we see mean. When you look at the genome of a tumor tissue, for example, there may be thousands of mutations, but only some will cause cancer. What our laboratory has shown is that having cancer is not so common in humans. The problem is that we are such a recent species that our genomes are very similar to one another, and we cannot distinguish whether a mutation in a tumor tissue is naturally present in humans or not.

What do primates have to do with it?

— They have two or three times more diversity than we do: there are 500 species of primates that have been evolving differently for tens of millions of years. Therefore, the combined power of what has happened to chimpanzees, gorillas, marmosets, and macaques allows us to know very well which mutations a genome like ours can tolerate without causing disease. Now I can take a tumor tissue sample and look at all the mutations I find to see which ones are present in primates. If a mutation is common in most primate species, it is most likely not disease-causing. But if I find one that no other primate has, it is suspected of destabilizing cell biology. Having all these primate genomes has allowed us to develop an algorithm that allows us to classify mutations not seen in any primate, and this allows us to say whether or not they are likely to cause disease.