# Intersections: Mathematics and the biologist

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- Intersections: Mathematics and the biologist

## Intersections: Mathematics and the biologist

Clare Horscroft is currently studying for a PhD in Human Development and Health at the University of Southampton.

**How would you characterise your current work?**

My project is on developing and applying mathematical models to find evidence of natural selection in the DNA of humans and chickens. It is super interesting learning about the evolutionary evidence we can see today, such as humans evolving the ability to drink milk into adulthood, and the implications for our future in immunology, for example in HIV immunity.

**How do you feel about maths? **

I’ve loved it ever since I was young! I liked it because it is logical and there was always a “right answer”, as opposed to other subjects like English Lit – you can’t argue with a 7! It probably helped that it came to me quite naturally. I still enjoy that satisfaction of getting an answer right or being able to derive a formula correctly.

**What is it about your work that is mathematical?**

Most of what I do is mathematical! When natural selection occurs in a population, it creates areas of the genome containing mutations which are highly correlated to each other (that is, if you have mutation A, you are also likely to have mutation B). Finding these areas which have significantly higher correlation than the rest of the genome is done by applying mathematical models. These models can range from simple statistics to complex machine learning methods.

**How do you use maths, calculation or numeracy in your work? What tools do you use to help you?**

To do calculations I use the R programming language. R is great as it is free, open source, and widely used. It means if you want to perform some analysis or apply some statistical test, it is likely someone before you has already written a package for that so you don’t have to waste your time reinventing the wheel. I also have access to the IRIDIS high performance computing facility at the University of Southampton so I am able to analyse some pretty big datasets in a much shorter amount of time than I would otherwise be able to.

**Do you think maths is creative? If so, how?**

I think you have to be able to keep an open mind – for example if you are reading a paper where someone has applied a certain method, thinking about how you could apply that method to your problem or adapt it, or combine it with other methods, is certainly a creative skill. Writing code to build working, efficient mathematical models is definitely an art form!

**Do you use or rely on any maths that you learnt in school?**

Of course, everything you learn in school is a building block onto which you can build more and more specialised and complex knowledge. For my work especially this includes algebra, probability and statistics. But even in everyday life I use mathematics all the time, for example in the supermarket working out if I’m getting the best value toilet paper!

**How would you change the school curriculum, if you had the chance? Why?**

I would make sure that there was a more practical focus to everything. I recently met a science teacher who said that she starts every lesson with how what they will learn that day affects the lives of the students, and how it is relevant to them. When I first came across decision mathematics and operational research at A level I was really engaged as it was the first time I had really encountered maths with a practical purpose that wasn’t physics! I think it’s so important for students to be able to grasp the basics as I can think of no area in life that doesn’t involve some kind of mathematics. It’s also important for students who will go on to further education to have a broad knowledge of mathematics to build on in their further studies.

You can find Clare Horscroft on LinkedIn here.

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