NEET BIOLOGY

Detailed explanation-1: -If two or more species share a unique physical trait they may all have inherited this trait from a common ancestor. Traits that are shared due to common ancestry are homologous structures. The similar bone arrangement of the human, bird, and whale forelimb is a structural homology.

Detailed explanation-2: -Homologous structures indicate that the species came from a common ancestor and are related through evolution. When two different species have the same bone structure, it indicates that they once had a common ancestor.

Detailed explanation-3: -In convergent evolution species of different ancestry have analogous traits. In parallel evolution, two species evolve independently of each other and maintain the same level of similarity. Therefore, homologous organs indicate both common ancestry and divergent evolution.

Detailed explanation-4: -The most important thing to remember about homologous structures is that they share common ancestry. In other words, only organisms that are somehow related to each other can have homologous structures. For example, a chimpanzee’s arm and a human’s arm are homologous structures.

Detailed explanation-5: -Homologous structures are similar structures that evolved from a common ancestor.