Darwin explained that evolution occurred by a mechanism called(hybridization, Natural Selection, Mutation, or Variation)
The environment determines the
(Fitness, Ancestry, Intelligence, or Hybridization)
of an organism, which depends on (Tolerance, adoptions, ecosystems, or Habitats)
that help the organism survive and reproduce

Darwin explained that evolution occur by a mechanism called NATURAL SELECTION. The environment determines the FITNESS of an organism which depend on ADAPTATIONS that help the organisms to survive.

Explanation:

Theory of evolution was first formulated in Darwin's book in 1859 by Charles Darwin,an English naturalists.

The theory states that organisms rise as a result of natural selection ofsmall and inherited traits, which the organism to adapt or be fit to survive and reproduce in its environment.