Question

The economy of a small town in Europe depended on agriculture in 1920. With the development of industries in 1940, the economy relied more on industries. Due to the release of lot of soot by these industries, the bark of the trees became permanently dark within ten years. The primary source of food for birds was a certain species of moth which spent most of their time sitting on tree trunks and laying eggs in the bark of the tree.

Year	White moths (%)	Black moths (%)
1920	95	5
1940	95	5
1950	95	5
1960	50	50
1970	20	80
1980	5	95

Based on the above table, the wings of the moth and wings of birds show

• A. Homologous structures
• B. Autologous structures
• C. Divergent structures
• D. Analogous structures
• E. Emergent structures

Answer 1

Answer: (D)

Analogous structures

Based on the above table, the wings of the moth and wings of birds show analogous structures.

Analogous structures pertain to the various structures in different species having the same appearance, structure or function but have evolved separately, thus do not share common ancestor. Examples of analogous structures include: wings of insects and birds used for flying.

Animals with analogous structures are not necessarily very closely related genetically, despite the fact that they may have evolved similar bodily structures. For example, bats, bluebirds and butterflies all use wings to fly. These three creatures, however, are dissimilar in many other aspects, for bats are mammals, bluebirds are birds and butterflies are insects. Likewise, a dolphin and a shark both have flippers, a fin and a similar body shape, but the shark is a fish and the dolphin is a mammal, which makes it more closely related to a rat than to the fish with which it shares the oceans. Because the shark and the dolphin both live in the sea, they have evolved similar bodily structures to cope with life in that particular environment, but they are otherwise very different. This fact has made it difficult, sometimes, for scientists to make accurate classifications of animals, especially before scientists knew how to work with DNA.