The theory of evolution by natural selection was finally formulated by:

1. Earlier explanations held that organisms were made perfectly adapted and did not change. 2. Over time, scientists came to understand that life was constantly evolving on Earth. 3. Those earlier theories were disproven, but their development contributed to the theory of evolution that was finally formulated by Charles Darwin. 4. Mendel worked on inheritance and Linnaeus on classification. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 18 'Evolution and the Origin of Species', sections 18.1-18.3_