Harte's classic short story "The Luck of the Roaring Camp" contains several assumptions about nature.

Some of them are about gender. It is an assumption about what it means to be male or female when Harte says of Cherokee Sal that she lacks " her sex’s intuitive tenderness and care."

A second assumption is that there should be an alignment between people's physical selves and their characters...but there isn't. Look at the discussion of the men in the camp, and their character, early in the story.

Other assumptions address nature in general more specifically. After the child is born, he is very healthy, due (perhaps) to the " invigorating climate of the mountain camp." This indicates some environments are more innately healthy than others.

Another assumption emerging after the baby is born is that people should be aware of the beauty in nature...but often aren't. The men's work and entertainment blinded them to natural beauty. Once they are taking care of the baby, they are aware of the beauty in rocks and pebbles.