# Teaching Dynamics to Biology Undergraduates: the UCLA Experience

The goal of *Intermediate Physics for Medicine and Biology*, and the goal of this blog, is to explore the interface between physics, medicine, and biology. But understanding physics, and in particular the physics used in *IPMB*, requires calculus. In fact, Russ Hobbie and I state in the preface of *IPMB* that “calculus is used without apology.” Unfortunately, many biology and premed students don’t know much calculus. In fact, their general math skills are often weak; even algebra can challenge them. How can students learn enough calculus to make sense of *IPMB*?

A team from UCLA has developed a new way to teach calculus to students of the life sciences. The group is led by Alan Garfinkel, who appears in *IPMB* when Russ and I discuss the response of cardiac tissue to repetitive electrical stimulation (see Chapter 10, Section 12). An article describing the new class they’ve developed was published recently in the *Bulletin of Mathematical Biology* (Volume 84, Article Number 43, 2022).

There is a growing realization that traditional “Calculus for Life Sciences” courses do not show their applicability to the Life Sciences and discourage student interest. There have been calls from theAAAS, theHoward Hughes Medical Institute, theNSF, and theAmerican Association of Medical Collegesfor a new kind of math course for biology students, that would focus ondynamicsandmodeling, to understand positive and negative feedback relations, in the context of important biological applications, not incidental “examples.” We designed a new course,LS 30, based on the idea of modeling biological relations as dynamical systems, and then visualizing the dynamical system as a vector field, assigning “change vectors” to every point in a state space. The resulting course, now being given to approximately 1400 students/year at UCLA, has greatly improved student perceptions toward math in biology, reduced minority performance gaps, and increased students’ subsequent grades in physics and chemistry courses. This new course can be customized easily for a broad range of institutions. All course materials, including lecture plans, labs, homeworks and exams, are available from the authors; supportingvideos are posted online.

This course approaches calculus from the point of view of modeling. Its first example develops a pair of coupled differential equations (only it doesn’t use such fancy words and concepts) to look at interacting populations of sharks and tuna; the classical predator-prey problem analyzed as a homework problem in Chapter 2 of *IPMB*. Instead of focusing on equations, this class makes liberal use of state space plots, vector field illustrations, and simple numerical analysis. The approach reminds me of that adopted by Abraham and Shaw in their delightful set of books *Dynamics: The Geometry of Behavior*, which I have discussed before in this blog. The UCLA course uses the textbook *Modeling Life: The Mathematics of Biological Systems*, which I haven’t read yet but is definitely on my list of books to read.

My favorite sentence from the article appears when it discusses how the derivative and integral are related through the fundamental theorem of calculus.

We are happy when our students can explain the relation between theCOVID-19“New Cases per day” graph and the “total cases” graph.

If you want to learn more, read the article. It’s published open access, so anyone can find it online. You can even steal its illustrations (like I did with its shark-tuna picture above).

I’ll end by quoting again from Garfinkel et al.’s article, when they discuss the difference between their course and a traditional calculus class. If you replace the words “calculus” and “math” by “physics” in this paragraph, you get a pretty good description of the approach Russ and I take in *Intermediate Physics for Medicine and Biology*.

The course that we developed has a number of key structural and pedagogical differences from the traditional “freshman calculus” or “calculus for life sciences” classes that have been offered at UCLA and at many other universities. For one, as described above, our class focuses heavily on biological themes that resonate deeply with life science students in the class. Topics like modeling ecological systems, the dynamics of pandemics like COVID-19, human physiology and cellular responses are of great interest to life science students. We should emphasize that these examples are not simply a form of window dressing meant to make a particular set of mathematical approaches palatable to students. Rather, the class is structured around the idea that, as biologists, we are naturally interested in understanding these kinds of systems. In order to do that, we need to develop a mathematical framework for making, simulating and analyzing dynamical models. Using these biological systems not purely as examples, but rather as the core motivation for studying mathematical concepts, provides an intellectual framework that deeply interests and engages life science students.

*Originally published at **http://hobbieroth.blogspot.com**.*