Quantitative genetics: evolution of multiple traits
Organisms have many traits. Their survival and reproduction depends on how all of the traits function together. Natural selection works on the whole organism, not individual traits, and if traits are genetically correlated, selection on one trait may lead to an evolutionary response in other traits.
The basic math is pretty similar to what you've already seen. If you happen to be familiar with multiple regression, you'll see a pretty striking application of it here. If you haven't encountered multiple regression before, don't worry, I'll explain what you need to know.
No recording of today's lecture. Sorry. I forgot to turn on the recorder.