NEET BIOLOGY

Detailed explanation-1: -But beneath the skin, the forelimb bones of these animals are startlingly similar. These likenesses in structure, called homologies, are the result of descent from a common ancestor.

Detailed explanation-2: -Homologous structures share a similar embryonic origin; analogous organs have a similar function. For example, the bones in the front flipper of a whale are homologous to the bones in the human arm. These structures are not analogous. The wings of a butterfly and the wings of a bird are analogous but not homologous.

Detailed explanation-3: -Comparison to Human Arm in Function whale Whale has a much shorter and thicker humerus, radius, and ulna. Much longer metacarpals. Whale fin needs to be longer to help in movement through water. Thumbs are not necessary, as they don’t need to pick up and grasp things.

Detailed explanation-4: -Bat wings and whale fins are a good example this. While they don’t appear similar from the outside and function differently, the skeletal structure of these two features are actually very similar, as they are rooted in a common ancestor. Most hands, wings and flippers in mammals are homologous.