Many things in nature were not made for us or anyone else to look at so what’s going on? I think the answer lies in remarkable convergence between features of art that we value because they provide evidence of human skill and the features of natural things that have evolved and persisted because these features have given them staying power and survivability. That’s to say there’s a convergence between our sense of aesthetically good form and nature’s selection of evolutionarily stable form.-- from Beauty's Child: Sexual Selection, Nature Worship and the Love of God. Nicholas Humphrey on (Edge 300)
In the case of animals and plants part of the reason for this is the ordinary working of natural selection. That the whole body grows in an ordered and harmonious way just is the best way of building a complete machine. So even without the added stimulation of sexual selection good form would prove to be evolutionarily adaptive.
Why is being in the presence of beautiful things adaptive?
A. The things as such as are valuable to us
1. Beauty is a sign of something good (for us) about the object
2. Beauty is the thing that’s good for us about the object
B. The things as such have no value, but in approaching them we approach something else that has value
1. Safe environment
2. Good people.