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
A common ancestor refers to an ancestral organism or gene pool shared by two or more descendant species.
Related terms
Cladistics: This is a method of classifying living organisms based on the most recent common ancestors. It's like organizing a family reunion based on who shares which grandparents.
These are structures in different species that have similar form or function due to shared ancestry. Like how you and your cousin might both have grandma’s nose!
This occurs when unrelated organisms independently evolve similar traits as they adapt to similar environments. It's like two unrelated people both becoming chefs because they live in food-loving cities.