What is the principle that each living species has descended, with changes, from other species over time?

• A. Descent with Modification
• B. Mutation
• C. Genetic Drift
• D. Natural Selection

Answer: (A)

Descent with modification is the idea that all living species are related through common ancestors and that lineages accumulate changes over many generations, leading to the diversity we see today. This principle fits best because it describes both the shared ancestry of organisms and the gradual changes that produce new species over time.

Mutation, while it provides new genetic variation, is a mechanism that creates differences rather than the overarching pattern of how species come from previous ones. Genetic drift refers to random changes in allele frequencies, especially in small populations, and doesn’t capture the broad pattern of lineages changing over time. Natural selection describes how certain traits become more common because they improve reproductive success, but it’s a process acting on variation rather than the general pattern of descent with modification itself.