No, I'm a (former) mathematical physicist. My main source for that particular paragraph is a math bio textbook I used in grad school (standard yellow book), combined with attendance at a huge number of math bio seminars [1].

However, if you want a source for the general statement that a lot of systems biology works out to ODEs, I'll point you to some general models which form the basis for most work in mathematical neuroscience:

http://en.wikipedia.org/wiki/Biological_neuron_models

[1] If you are in quantitative grad school, I highly recommend you to do the same even if you are studying something completely different (e.g., quantum physics or abstract algebra). The math and biology are usually simple and explained very well, and you wind up learning a lot about both.