steppingstone

Stepping stone is a term that refers to both a literal stone used to step across a small obstacle and a figurative means to progress toward a larger goal. The metaphor implies that each stage is temporary but necessary to reach a destination.

The phrase likely originates from the image of stepping across a shallow stream using stones placed at intervals.

In geography and travel, a stepping-stone route describes a sequence of islands, peninsulas, or towns that enable navigation or migration between distant regions. Historically, explorers and migrants relied on stepping-stone routes through archipelagos or coastlines to reach new areas.

In population genetics, the stepping-stone model describes gene flow in populations arranged in a spatial grid, where migration occurs between neighboring demes rather than between all pairs. It helps model spatial patterns of genetic variation and the effects of geographic distance on migration.

In career and education contexts, a stepping-stone job or stepping-stone program refers to a position or course of study that provides experience or credentials that facilitate advancement to a desired role or field. The term emphasizes progression through intermediate steps rather than immediate placement.