Final answer:
The theory of evolution by natural selection describes how species can change over time. Plato believed species were unchanging but ancient Greeks expressed evolutionary ideas. Darwin published a book on evolution in 1859, outlining the theory.
Step-by-step explanation:
The theory of evolution by natural selection describes how species can change over time. This idea was suggested and debated before Charles Darwin. Plato believed that species were static and unchanging, but there were ancient Greeks who expressed evolutionary ideas. Darwin published a book on evolution in 1859 titled On the Origin of Species, which presented the theory of evolution by natural selection and provided evidence for the occurrence of evolution.