Does our body expect to experience seasons?

Are we genetically programmed to physiologically expect the changing of the seasons?

In animals we see the genetic response to seasons, like some animals turn white when snow starts to fall. Are those animals kind of required to go through that shift to be healthy?? Are they just responding appropriately, but could be just as healthy with a sustained summer…?

As for humans…I don’t think there is a change we really go through, except tanning in summer. Do we need that tanning period? Do we need to get a certain amount of annual cold weather for super optimal conditioning?