Certified Professional Dog Trainer – Knowledge Assessed (CPDT-KA) Practice Exam 2026 - Free Dog Trainer Exam Practice Questions and Study Resources

Selective human-guided breeding drives genetic changes that alter both behavior and biology in domesticated animals. When humans consistently choose for traits like tameness, sociability, and compatibility with human environments, those preferences shape which genes are passed on over many generations. This leads to a suite of changes, not only in outward appearance but also in behavior and physiology—so dogs may become more tractable and less fearful, while their bodies and systems adapt to living with people (for example, changes in brain chemistry related to stress responses, as well as morphological shifts that accompany long-term domestication).

This differs from natural selection in the wild, where there are no deliberate human goals guiding trait changes. Domestication is driven by human intent, often resulting in faster and different directions of change than would occur naturally. It also involves more than just physical traits; behavior is a central aspect because the ability to live with humans is a key feature selected for. It isn’t about climate adaptation, which is an environmental pressure rather than the process of breeding for particular traits.

So the statement accurately reflects that domestication results in extensive behavioral and biological changes due to selective breeding.