Yes, the simulations are of one population only. In the density-dependent simulation, the population arguably splits into three separate ones, though, which may be taken to demonstrate ecological speciation in asexuals (there's no sex in these simulations, btw).

As is common in evolutionary simulations, the population size is indeed forced to be constant. However, you are assuming that being in the blue territory is very low fitness, which is not the case. Blue is a fitness of 0.1, while red is 0.14. This is a difference that selection can detect, so to speak, but not one…

As is common in evolutionary simulations, the population size is indeed forced to be constant. However, you are assuming that being in the blue territory is very low fitness, which is not the case. Blue is a fitness of 0.1, while red is 0.14. This is a difference that selection can detect, so to speak, but not one…