Artificial Selection in Dogs
Artificial selection by humans shapes dog diversity, stemming from wolves.
Evolution of Dogs: Five Key Criteria
Evolution from wolf to dog involves variation, inheritance, selection, time, and adaptation.
Variation
Dogs digest starch due to a gene duplication (AMY2B), unlike wolves.
Variation exists in AMY2B gene copies among dog breeds, affecting starch digestion.
Inheritance
Bully Whippets have a myostatin mutation causing increased muscle mass.
Genetic combinations of the myostatin mutation affect muscle development.
Selection
Humans selected dogs for traits like size (e.g., Great Danes vs. dachshunds).
Dachshunds' shorter legs were selected for hunting.
Directional selection shifts traits like leg length through breeding.
Time
Dogs evolved from wolves, branching off over time.
Dogs (Canis lupus familiaris) are a subspecies of wolf.
Adaptation
Dogs adapted for specific jobs (e.g., Irish Wolfhounds, Old English Sheepdogs).
Artificial selection drives adaptation to suit human needs.
Adaptation results from variation, inheritance, selection, time.