Charles Darwin was a great admirer of Humboldt, and was very familiar with his work.

That work involved extensive description of the geographic distributions of plants – i.e. he founded botanical geography, a form of biogeography – especially in South America.

I expect that this work played into and influenced Darwin’s own observations of the geographic distributions of animals and animal fossils – i.e. Darwin’s own work in biogeography. Darwin’s observations on these matters played a key role in his development of evolutionary theory.