Darwin went to the continents of Africa and South America, wherein both of them have a tropical grassland/Savanna biome. The grasslands in these continents gave him a chance to notice that species do vary globally. He observed the similarities between the different large, flightless birds species–rheas, ostriches, and emu.

Darwin’s voyage has allowed him to compare the animal species living in the different continents and islands, as well as the fossils of extinct species. When he tied up all the pieces of evidence from his journey, he proposed that evolution is a natural process and the environment plays an important role in shaping an organism. He explained that this was how modern organisms have evolved from their extinct ancestors. More importantly, it is a process that is responsible for the great variety of life that we see on Earth.

Darwin’s entire voyage has given him the chance to compare the animal species living in the different continents and islands, as well as the fossils of extinct species. This led him to discover the three patterns of biological diversity: species vary globally, locally, and over time.