Ramblings on Depth and Breadth in Introductory Science Teaching

About a week ago, I was having dinner with a friend, and the topic of teaching in various science disciplines came up; he got his degree in biology, while I got mine in physics. One of the things that we both noticed in our undergraduate careers was that introductory physics classes tend to go fairly deep right away, focusing only on a few broad topics, whereas introductory biology classes go much more for breadth, with the depth coming in specific topics in later classes. It took us a little time to think of why this might be. I think we came up with a reasonable explanation, so follow the jump to see what that explanation might be (along with extensions of it).

A few warnings are in order. One is that although I've gone through a full undergraduate course sequence in physics, I have only taken one introductory biology class in my undergraduate studies, so I'm essentially comparing an insider view of one subject to an outsider view of another; worse, my insider view of physics was built over 4 years so it is fairly fresh in my memory, whereas my outsider view of biology came in a single semester 4 years ago, so my memory of it is rather fading (though it is augmented by the problem sets and exams that I saved on my computer). Therefore, some things I say about biology might as well come from my posterior. Given all this, if you see that I say something horribly wrong about biology (or physics, for that matter), tell me in the comments! The other is that this post may seem rambling and incoherent at times; that's because this is more of a brainstorm than anything else.