It all began when he took a ship to the Galapagos Islands and took careful observations about both the geology and biology of the islands. Darwin was particularly struck by the differences between the inhabitants of the different islands. Particularly the finches caught his eyes there were several variations between the species on each island. On each island every beak supported that specific bird in it’s environment. A finch that lived on an island with trees and bushes that dropped seeds would have a small beak to pick up those seeds. A finch that lived on an island with hard fruits would have a beak that could grasp a stick to break open those fruits. A finch that lived on an island with access to large quantities of insects would have a sharp narrow beak to kill and eat those insects. Charles Darwin also observed that tortoise that lived on the mainlands varied from those on the islands. Eventually environments changed so drastically that these tortoise evolved into new species. These weren’t just random changes that occurred, they were specially adapted to live on the islands rather than the mainlands. This goes even further when the tortoise on the islands start to adapt differently. A tortoise on the larger islands, which contained vast amounts of grass and vegetation, grew extra heavy and had dome like shells. While on the smaller islands with little vegetation the …show more content…
Evidence of this can be found in several categories stretching from comparative anatomy to DNA comparisons. An example of comparative anatomy is the species of whales. Whales just like land mammals have placentas and give live birth, feed milk to their young, are warm-blooded, and have hairs. The biggest similarity is the presence of lungs instead of gills in a whale. They have the ability to breath due to the use of a blowhole similar to a nose and nostrils. If you go and look at the skull of a whale you can see how the blowhole splits into two nasal passage similar to a human nose and other land mammals noses. Another significant feature in a whale is the arm, wrist, hand, and finger bones present within the fin of a whale. These bones are usually only found in other land mammals. There is also bones where the hind legs of a whale should be that resemble a hip bone and leg bone with an attaching ball joint. These bones have no use in present day whales but might have helped previous species of whales. You can even see in another category of evidence called fossil records how previous species of whales had a more formed version of legs then present day whales. Going back even