Seven questions with Matilda Brindle

This week, meet Matilda Brindle, a PhD student based in UCL Anthropology, who is researching the evolution of auto-sexual behaviours (masturbation) in primates.

Matilda's current research project is focused on the evolution of the baculum, or penis bone, one of the most enigmatic structures in the animal kingdom.

Research project: Evolution of the baculum

Department: Anthropology

Members of team: Matilda Brindle and Dr Kit Opie

Tell us more about your research project:

The baculum, or penis bone, is one of the most enigmatic structures in the animal kingdom. It is only present in mammals, and not all mammals at that. But up until now relatively little was known about how it evolved or why certain mammals might have one.

Our study used the latest phylogenetics (statistical methods which allow you to model the evolution of a trait given its pattern of descent) to reconstruct how the baculum evolved across mammals.

We then examined whether high levels of competition between males for females was likely to be one of the factors influencing baculum evolution in primates.

What we found was that the baculum first evolved after marsupials split from placental mammals around 145 million years ago (mya) but before the common ancestor of primates and carnivores evolved around 95 mya.

In line with our predictions, we discovered that primate species where many males and females mate with one another (which leads to high levels of male-male competition) tended to have longer bacula than species in which females only mated with one male.

What makes it so important (and interesting)?

I think that anything that helps to piece together the story of how the animal kingdom became so diverse is quite exciting. We focused on the baculum because it is interesting, in and of itself, and has been relatively understudied. However, I feel that our study also helps to demonstrate how useful and exciting phylogenetic methods can be.

By modelling evolution based on the traits of living species you can reconstruct how any trait evolved, be it physical or behavioural, without needing to find something in the fossil record. The baculum is a physical trait, but fascinating studies have also examined the evolution of things like mating systems or language, which obviously do not fossilise.

This is a hugely exciting tool, not just for evolutionary biologists, but for anyone interested in how life has evolved.

What has been a personal highlight so far?

For me, the highlights of the research were the moments when we first saw the results of our analyses and realised, not only that our hypotheses had been correct, but that we were the first people in the world to have discovered what we did.

It's wonderful to be able to contribute to science in that way and add another small piece to the puzzle of how animals became the way they are today.

Explain some of the challenges involved in working on a research project.

You need to be so perseverant when carrying out a research project as it throws up so many unexpected challenges, from computer malfunctions to unexpected results.

Things can (and do) change or go wrong at every stage of your research, so it helps to be organised and try and work to a timetable, whilst remaining flexible enough to deal with any problems that may arise.

What advice would you give to an undergraduate student hoping to pursue a research career?

It may sound obvious, but all research has to start somewhere - mine began by chance after a lecturer went on a slight tangent and introduced the class to the peculiar bone that is the baculum.

After a quick online search it became apparent that there were more questions than answers - so Kit and I decided to research it ourselves.

So my advice would be: if you find a topic that interests you, explore it, and if you find a question that hasn't been answered, try and answer it yourself!

Any idea what's next after the project finishes?

I'll be getting started on my PhD in which I will be researching the evolution of auto-sexual behaviours (masturbation) in primates.

Describe your perfect evening (or weekend) after a long week.

Lazy mornings with good coffee and a leisurely breakfast, pub lunches with friends and long walks.