1. The scientific theory of evolution is supported by multiple lines of evidence, including the fossil record, comparative anatomy, and observed changes over time.
2. Early evolutionary thinkers like Lamarck proposed different mechanisms of evolution than what is accepted today, such as the inheritance of acquired traits based on environmental needs.
3. Modern evolutionary synthesis incorporates Darwin's idea of descent with modification through natural selection acting on random genetic mutations and variations that arise during reproduction. Traits that increase reproductive success and survival become more common in populations over generations.