Red squirrels usually eat hazelnuts, but due to a reduction in their food source, they had to share resources with gray squirrels. The number of red squirrels decreased over time, and gray squirrels gradually replaced the red squirrels because they are better adapted to the environment. This is an example of(1 point)

Responses

natural selection.
natural selection.

survival of the fittest.
survival of the fittest.

competitive exclusion.
competitive exclusion.

resource partitioning.