Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The direction of evolution refers to the path that evolutionary changes take over time, leading towards increased complexity, simplicity, or staying about the same.
This is when members of a single group or lineage rapidly diversify into many new species by adapting to varied environments. Like hikers exploring all paths from one crossroad on their trail.
This occurs when distinct species independently evolve similar traits due to having to adapt to similar environments or ecological niches - just as different hikers might end up at the same viewpoint because it offers the best view.
Stasis: This is when a species changes little over a long period of evolutionary time. It's like a hiker who decides to set up camp and stay in one place on the trail for a while.