How did Darwin arrive at the idea about species variation

We can see some of the most important patterns Darwin noticed in distribution of organisms by looking at his observations of the Galápagos Islands off the coast of Ecuador. Darwin found that nearby islands in the Galápagos had similar but nonidentical species of finches living on them.

maritime tropical may be your answer.

a- multicellular

b-eukaryotic

c-no cell wall

d-heterotrophic

e-autotrophic