While hiking in South America, a member of your group becomes ill with fever and chills after passing through a swampy area. A resident of the area removes bark from a nearby tree and has the ill person chew on it, which has a beneficial effect. The effective ingredient was likely from the tree.

The effective ingredient was likely quinine from the cinchona tree.

Explanation:

Quinine is obtained from the bark of the cinchona tree and it is used in the treatment of malaria. Malaria is transmitted to humans by several species of mosquitoes. In South America, Malaria is mostly transmitted in rain forest areas in northern countries. Therefore, in the situation we are studying here, the member who became ill might have been infected. The quinine present in the cinchona bark made him feel better.

it depends on which society you are referring to. many civilization performed rituals so the gods would with their growing season but the most well known is that of the aztecs. they would make sacrifices, usually animals, but sometimes humans as well.

they could find out our specific needs.