The gradual drying of the soil caused by its diminished ability to absorb water results in the further loss of vegetation, so that a cycle of progressive surface deterioration is established.
The physical structure of species competing for resources in the same ecological niche tends to gradually evolve in ways that allow them to occupy different niches.
Our present understanding of the Sun's luminosity holds that it should have progressively increased, not decreased, over the course of Earth's history.
Feelings of hopelessness among medieval workers trapped in the poverty cycle gradually lessened as it became possible for women's labor to supplement a family's money income by more than pennies.