What did Darwin infer from his observations of organisms in south America and the Galapagos's islands?

Answer 1

All the species of finches on the Galapagos Islands appear morphologically very similar, varying mostly in terms of beak size and behavior; they all look very much like a species of finch from the mainland of South America. This suggests that all the finches on the Galapagos are descended from one original colonist species that went through an adaptive radiation. Because of the small, isolated environment of the Galapagos, the finches have become the topic of extensive study into natural selection. The studies that have been conducted on the finches show strong selection for larger beaks during droughts. These data show that climatic changes can have profound effects on the morphology of a species and potentially lead to the formation of new species. When Darwin visited the Galapagos, he observed and collected some of the finch species, believing that they represented a very diverse set of birds that were not closely related. Their significance was not recognized until later, when ornithologist John Gould pointed out that the birds were all closely related finches (Desmond and Moore 1991). But because Darwin originally collected some of the specimens and because the finches showed so much evidence for evolution and natural selection, they have been dubbed "Darwin's finches." This has led many people to conclude (mistakenly) that Darwin's theory of evolution was specifically inspired by the finches

The zoologist Thomas Bell showed that the Galápagos tortoises were native to the islands. By mid-March, Darwin was convinced that creatures arriving in the islands had become altered in some way to form new species on the different islands, and investigated transmutation while noting his speculations in his "Red Notebook" which he had begun on the Beagle. In mid-July, he began his secret "B" notebook on transmutation

Answer 2

1) Finches have different colors in different areas.

2) Finches beak size depends on their diet

3) Tortoises are larger where there are less predators.

Answer 3

Darwin inferredthat the organisms in South America and the Galapagos islands were different in each generation, even if they were the same species.

Answer 4

He noticed that species similar to others in other parts of the world differed from the ones he saw on that isolated island. They had adapted to their environment.