The heat maps used in the animation I posted yesterday plotted change over time in counts of countries in each cell of a two-dimensional space representing different kinds of politcal institutions. Over the 211 years in question, however, the number of countries in the world has grown dramatically, from about 50 in 1800 to well over 150 in 2011. For that reason, a couple of commenters wondered whether we would see something different if we plotted proportions instead of counts, using the size of the total population as a denominator in each cell. Proportions better fit the ideas behind a fitness landscape, so I added a line to my code and gave it a whirl. Here’s what I got:

To my eye, there aren’t any big differences in the patterns we see here compared with the ones based on counts. Re-watching the animation today, though, here are a few other…