Which concept captures the idea that all life shares a common origin and has diverged over time?

Which concept captures the idea that all life shares a common origin and has diverged over time?

• A. Natural selection
• B. Descent with modification
• C. Fitness
• D. Embryology

Answer: (B)

Descent with modification expresses that all life comes from a common ancestor and has diverged into the diversity we see today as lineages accumulate changes over time. It captures both the unity of life and the branching, differing forms that arise as descendants adapt to different environments. The idea is not just that organisms change, but that they are related through a shared origin, with each generation passing on modified traits to its descendants. Natural selection explains how those changes accumulate by differential survival and reproduction, but the broader concept at stake is the shared ancestry and divergent evolution described by descent with modification. Embryology studies developmental patterns, which can reveal relationships, and fitness is about reproductive success, not the overarching pattern of origin and divergence.

Descent with modification expresses that all life comes from a common ancestor and has diverged into the diversity we see today as lineages accumulate changes over time. It captures both the unity of life and the branching, differing forms that arise as descendants adapt to different environments. The idea is not just that organisms change, but that they are related through a shared origin, with each generation passing on modified traits to its descendants.

Natural selection explains how those changes accumulate by differential survival and reproduction, but the broader concept at stake is the shared ancestry and divergent evolution described by descent with modification. Embryology studies developmental patterns, which can reveal relationships, and fitness is about reproductive success, not the overarching pattern of origin and divergence.