The house mouse, beloved of cats, only arrived in North America with Europeans, so there aren’t millions of years to make up a story about how things happened. Well, here are some things that happened:
The western and eastern mice from cold climates shared changes in 16 genes, many involved with the regulation of body temperature.
“This suggests that there’s some predictability to evolution, that some of the same genes have changed in parallel to give rise to similar traits,” says Nachman.
Jake Buehler, “Mice on opposite North American coasts evolved the same way ” at New Scientist
Well, wait. It’s not just the same outcome; it’s the same genes that changed. That suggests an underlying pattern. The pattern better fits Lee Spetner’s non-random evolutionary hypothesis,where adaptability is built in, as he set out in The Evolution Revolution (2014).
If there were any life form that would have built-in adaptability it would be mice. They need it.