Well … not exactly.
We’re worried a lot that we’re all getting fatter. The thing is, so are lab animals on restricted diets. Scientists are starting to think this may be because we live in climate controlled environments where we don’t have to shiver much.
Anyway, my point is that when we change our environment, natural selection takes advantage.
Which brings me to mice. Brains of mice are getting larger too. The current theory is that contemporary urban environments are more challenging for mice to live in, thus they need to be smarter, and so natural selection favors mice with bigger brains.
Yep … there’s mouse hillbillies.