Evolution & Natural Selection

Competition

Specialization

Variation

Selection

Fossils - Depth and Structures

Molecular Biology

Comparative Anatomy

Species locations

Selective breeding means that only the organisms with desirable traits will live to reproduce or be given the opportunity

Artificial selection is when humans dictate the traits that are desired (dogs, cats, horses, cows and so on)

Nature does a fantastic job of doing this, but it cannot happen with out genetic diversity.