Final answer:
Charles Darwin's 'On the Origin of Species' outlines his theory of evolution by natural selection, which is based on the principles of overproduction, variation within species, and differential survival and reproduction that leads to the adaptation and emergence of species over time.
Step-by-step explanation:
Charles Darwin's seminal work, On the Origin of Species, published in 1859, laid the foundation for the theory of evolution through natural selection. There are three main principles in Darwin's theory:
- Species have the innate potential to increase their numbers exponentially, but the food supply does not increase at the same rate, leading to a struggle for existence.
- Within any given species, there is variation in traits, and these variations can be inherited by the next generation.
- Natural selection acts upon these variations, meaning that individuals with traits that confer an advantage in the struggle for existence are more likely to survive and reproduce. Over time, this process can lead to the adaptation of species to their environments and the emergence of new species.
Darwin's journey aboard the HMS Beagle and his observations of biogeography, such as the unique adaptations of finches in the Galápagos Islands, provided crucial evidence for his theory.