Not necessarily. Evolution does not mean improvement, just adaptation. Unless there's some sort of biological pressure, such as a predator or an environmental r

Not necessarily. Evolution does not mean improvement, just adaptation. Unless there's some sort of biological pressure, such as a predator or an environmental risk, change won't happen or will happen much more slowly. The time scale is also important. In very cold environments, such as the ones described, everything happens at a much slower pace. Consider it this way: heat is a proxy for energy (technically it is energy, but it's not all the energy). Energy is required for change. Very cold environments mean less energy, which means less change over the same time period.