preLights talks to Leslea J. Hlusko

Professor Leslea Hlusko is a researcher at the Centro Nacional de Investigación sobra la Evolución Humana (CNEIEH), having recently moved from the Department of Integrative Biology at the University of California, Berkely. She is interested in how genes influence skeletal variation and how this has evolved through time. Alongside her research and teaching, she is also on the Managing Board for PCI in Paleontology, an initiative for peer review and recommendation of preprinted research in paleontology. We spoke to Leslea about her career, preprint advocacy, and the importance of framing anthropological research appropriately in discussions around human evolution and race.

Leslea J. Hlusko (photo credit CENIEH)

To start, I wanted to talk a little about your research: what are your main research interests and how have they developed to inform your research objectives at the moment?

I’m very interested in understanding how genetic mechanisms influence anatomical variation, and how that’s evolved over time. Given that I want that evolutionary time depth, I focus very much on skeletal traits – because then you can use fossils – and I specifically focus on teeth, because teeth preserve even better than the rest of the bones in the skeleton. My questions are very much driven by trying to understand humans, human evolution and where we come from, and why we are the way we are. But there’s also the genetic element there because selection operates on the genome through phenotype. So, I have the strong desire to figure out how we could use skeletal variation and how it’s changed through time to understand selection on the genome. I use a suite of different genetic inputs, a lot of that in quantitative genetic analyses, but also developmental genetic approaches as well, to look at skeletal and dental variation. It’s like Paleontology 2.0: still using anatomical variation but doing it in a much more genetically informed way.

Are teeth a well-conserved feature across different species?

Teeth are really conserved across mammalian and vertebrate development. But teeth look different from whales to primates to carnivores, so that begs the question as to how we get such variation across species. There’s lots of selection happening on that same fundamental developmental mechanism. My research is really aimed at trying to understand what genetic mechanisms lead to the variation we see between primates and carnivores and other mammals.

Most of my work has been in mammals and primates, where I’ve been using quantitative genetics. So far, we can see that there’s a lot of reasons to hypothesise that those mechanisms are similar, but this science is still very new. Quantitative genetics requires a reliable and large pedigreed population, which is uncommon. We’re still doing a lot of that comparative work across different types of primates, non-primates, and expanding that sample.

Is your background more anthropology or biology?

My undergraduate degree was in archaeology and anthropology. My desire to understand the human condition actually started out in the performing arts, but my brain is drawn to questions that have more simple answers. The science really pulled me in and increasingly drew me towards biology and genetics, away from the social sciences and archaeology. And ultimately, we are animals, and the evolutionary phenomena and biological frameworks are still the same, even though humans do some unusual things. You can’t just study humans as if there are no other animals, but I also think you can’t study other animals as if there are no specific behaviours that humans have.

You took a break between your undergraduate and going back to study for your PhD. What drew you back in to do a PhD and would you advocate having a gap in your studies?

The gap was actually not intentional. I didn’t get into graduate school the first time I applied, which in hindsight was a really good thing, because I’d applied to do Palaeolithic archaeology. I do find this interesting, but I wouldn’t have enjoyed doing it [for a PhD]. So, I took some time to figure out how to get into graduate school. I did not come from an academic family, so it was all very new. I thought that you didn’t talk to professors unless you were having trouble in a class; I did not have any idea how to do college then!

Those years were really useful for me to figure out what I was truly interested in. Why do I want a PhD? How do I do this? I went and found my way back to applying for graduate school in a different programme, and with a level of maturity and a level of purpose that I didn’t have before. I’d highly recommend that to everyone; take the time to think about what you’re doing and why, and is doing a PhD (which is a lot of work) what you really want to do? Working away from academia also gave me some really good perspective on my job now.

Moving into preprinting. You’re on the Managing Board of PCI Paleontology: could you explain a little bit about what it is and how it works?

Peer Community In (PCI) is essentially the idea of providing peer review for preprints. I think that many of us have seen, especially during COVID times, that you can post preprints, and that the media might pick them up and run with them, but that they haven’t got the polish that comes with peer review. PCI aims to provide that service for preprints with the hope that journals might bring those reviews in with the manuscript and facilitate the move from a manuscript to a published paper, rethinking how the whole system works. Rather than sending it to a journal, getting people to review a paper that might then be rejected and starting the whole process again, it would be a much more efficient use of everyone’s time for journals to pick and choose depending on what suited their publication mission.

This is going faster as a model in some disciplines than others, and paleontology seems to be on the slower end of the scale. Our subject matters are on a geological timescale, so maybe we’re just very slow to change! Even when I was asked to do this interview, I mentioned that I feel like a bit of a poser in the preprint world. I think it’s a fabulous idea, but it has been really difficult to jump into. I publish mostly with students and postdocs, early-career colleagues, and as preprints are not very common in our discipline, it’s hard to ask them to change how their CV looks when they’re applying for jobs. But I am committed to putting a paper on a preprint server this winter, it’s just making the transition and figuring out how to use preprints that has been more challenging than I thought it would be.

What do you think will cause that culture shift in paleontology?

I’ve been thinking about this for a while, and I think it’s probably going to need to be that senior people in the discipline start preprinting. And just navigating it with the early-career people that we work with, that we’re going to preprint and that we have to shake that mould of adherence. I think it’s even bigger than preprints themselves, it’s the idea that if you have a big impact factor paper you’ll get the job, or you’ll get tenure, and that’s the currency. I think the whole perspective needs to be shaken up.

I wonder if part of the difficulty is that in paleontology, the science has a lot of public appeal. There’s a big social media and journalistic drive for what is valued in our science. And if you preprint your work, you’ll get media attention from a preprint, which means you circumvent the publication in a journal (which is needed for career progression). I think there’s perhaps less of a chance of that with a paper in molecular or cell biology. If we could remove the media aspect of it, and it wasn’t so much of a currency with how we get jobs or keep jobs, then I think it would be much better for the science.

How did you become involved with the initiative?

I was approached by the people setting up the PCI Paleontology initiative. I believe in the mission and even though I feel like I haven’t done as much as I wish I had, it’s really nice to speak to people who are so passionate about preprinting.

Thinking more broadly about the impact of the science you do – I saw that your lab website has a Principles of Community section, which I think is a really positive idea. What inspired you to include this in your lab?

In the summer of 2020 in the US, we were still reeling from the pandemic, which was coupled with social unrest in response to the death of George Floyd (who was murdered callously by a police officer). My lab community is really tight; I work with wonderful, wonderful people, and we were staying closely connected via the internet. We were connected not just as our community, but also to the fact that our science is very important to the way that people engage with human variation and race, and how they understand race. In particular, my teaching at the University of California, Berkeley, is very tied to helping people understand human biological variation and making sure we don’t misunderstand race or fall for the abuses of racialized biology that lead to racist perceptions and how people interact with one another. My lab group has been driven by an anti-racist mission for a while, but the summer of 2020 brought it to the forefront and made us realise that we needed to do more within our own lab community to hold ourselves true to that, and that’s how we started to think about the principles of community.

Initially, they were based on principles of community that the University of California Berkeley recently implemented, so we took those and developed them over a series of weeks as a group. Then we met monthly on Zoom to make sure that everyone was comfortable with what we were doing and what we wanted to do. It was wonderful: it gave everyone the opportunity to not just talk about their science and their research, but to also talk about their experiences and reflect on them as a group. I’m just starting to build my new research group at CENIEH. We’ll implement those ideas again, especially for those of use working in human evolution. I think it’s really important that we should never forget that our science is more than just a scientific endeavour. It has a real world, social impact, and we have an obligation to make sure that we are sharing the science in a responsible way and being actively anti-racist in how we talk about our work.

I also noticed you have a list of alternative, inclusive terms on your website. As you said, a lot of this is particularly relevant to human evolution, but do you think that’s something other disciplines should think about doing too?

There are simple, small ways that we can change the way we speak about topics that feel more inclusive, without even realising they might have been exclusive before. I grew up saying a lot of terms that I never really thought anything of. But once people point these things out to you, you realise that language can make you feel like you don’t belong somewhere. As I’ve got older, I’ve heard more younger people come forward and explain that terms make them feel uncomfortable or excluded. It’s really easy to change words, and if it makes other people feel more comfortable then I’m happy to try to adjust my language. It’s not that hard to not hurt someone’s feelings. You might stumble the first time you say Western hemisphere instead of New World, but it feels really normal after you’ve done it a few times.

It’s part of the mission to make science more accessible: preprints help do that because they’re free, and changing language helps with that, too.

To finish: you’ve just moved to Spain, what prompted that and what’s next for you?

As we mentioned, human evolutionary biology is an interdisciplinary science, so there’s always been a sense of not really belonging in a specific department. I want to build on this science, and I didn’t feel like that I was in the environment to do that, so I decided to start something fresh and different. I just turned 50, so if I’m going to do something big, now is the time to do it!

The CENIEH research institute, where I’ve moved to, was envisaged by three paleoanthropologists leading the research at Atapuerca, a site just outside of Burgos here in northern Spain. Sierra de Atapuerca is a series of cave sites that document a little over a million years of human evolution. Around those sites those colleagues built up passion in the country for human evolutionary sciences. There’s a Museum of Human Evolution and of course the research centre itself. The CENIEH focuses on human evolution, and a range of sciences that go into it, such as geochemistry (dating), archaeology, paleontology and osteology. There are about 60-70 scientists who work at CENIEH which enables a truly interdisciplinary approach. I had a long-running joke that if they ever needed someone who studied teeth then I should apply – and then they did! And here I can pursue whichever direction I’d like to take and have a lot of scientific freedom among supportive and encouraging colleagues.

hris was interviewed by Helen Robertson, Community Manager for preLights. This interview has been approved by the interviewee.