What caused Darwin to develop his concept of evolution based on natural section?

Answer 1

Darwin's Finches:

In summary, Darwin noticed how specific adaptations between each species of Finch correlated to their surrounding environment. He ultimately concluded that at one point, a myriad of years ago, a single homogeneous group of finches flew to the Galapagos Islands. Then, as time passed, certain genetic variations that helped individuals survive became more popular among the Finch population (those with a helpful genetic variation became more likely to reproduce and pass on that gene mutation). However, since the islands differed from one another geographically and environmentally, different genetic variations (such as larger beak size) were more helpful on one island than another (if an island consisted mostly of ground nuts, a finch with a larger, more powerful beak could more easily eat and pass on his traits. If an island consisted mostly of insects, a more nimble, swift beak would be more preferable). [remember, the Finches did not try to make themselves have larger beaks, random, unpredictable genetic mutation did].

Answer 2

Darwin developed his concept of evolution based on natural selection after observing variations in organisms, competition for resources, and the struggle for existence in nature. He realized that organisms with advantageous traits were more likely to survive and reproduce, passing these traits to future generations, leading to species adaptation and change over time.