There doesn't exist a thing like "evolutionary purpose".
Evolution brought up an uncountable variety of living beings. They are totally different, but all fit very well in the environment where they live.
Evolution just happens, it has no purpose.
That's why it's absolutely useless and stupid to trying to extrapolate from evolution.
What you have said is just pure tautology.
Why the being is fit? Because it survives. Why it survives? Because it is fit.
Evolution in other words is not an external drive but a mean we use.
Studies on Innuit show they have evolved a peculiar metabolism, oxidative rate and body fat distribution. That doesn't mean that a drive lead the Innuits to evolve these characteristics. It just means that what they chose to do, the environment they chose to live allowed them to adapt and evolution allowed a mean to make this adaptation standard so each child is already born well adapted.
The concept of natural selection (as people consider it) is just a tautological nonsense.
There's no natural selection, natural selection is nothing but the end result of the history of who adapted and who didn't.
Inferring aestethic, artistic, moral, economical, cultural, social, affective values from this is just a dangerous meaningless mistake.