Selection as an Ecological Process

Having discussed relative fitness it is now time to turn to selection.  The first important point is to think about the “breeders” equation: r=h2s here r is the response to selection, h2 is the heritability, and s is the selection differential.  The important point is that evolution by natural selection (r) has two components, h2 […]

Putting the fun back in the fundamental theorem

One final entertaining aspect of relative fitness is Fisher’s Fundamental Theorem.  In his 1930 book Fisher states “The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time.”  This is a bit grandiose as will become clear below, but it is an interesting […]

Relative Fitness

My intention over the next several weeks is to delve into the five forces of evolution – selection, mutation, migration, drift, and environmental change – in more detail. I will deal with the forces separately, but all of the forces interact.  For example drift is not particularly exciting unless there is selection to magnify its […]

The Forces of Evolution

There is more to say about inheritance, and I will get back to it in the future, but for the moment I want to move on and give an overview of the forces of evolution.  As before, it is useful to return to the Hardy Weinberg Castle (HWC) equilibrium I discussed a couple of weeks […]