Describe the ways that humans both positively and negatively affect the environment and biodiversity.

Negatively:

overpopulation burning fossil fuels deforestationpollution

Positively:

protecting endangered speciesestablishing wildlife preserves and parksrecycling wastegrowing plants and vegetables/ home gardensCreating environmental regulations

Based on the information provided within the question it can be said that this scenario is describing the term known as directional selection. This term refers to a type of natural selection in which a certain characteristic of the species moves to one extreme as opposed to another. Which in this case refers to the bears size.