I’m guessing you’re asking what factors make up evolution, and my best answer to this would be natural selection leads to the making of evolution. Slowly over hundreds of years even thousands tiny differences are made in a species that helps it adapt to the environment it lives in. A good example is giraffes, as the trees gradually grew taller the ones with longer necks could still eat and survived. They bred their traits to the next generation. Those with shorter necks could not reach the trees, could not eat, and would die off.