Homology can be defined as the presence of common structures because of shared ancestry. Homology can involve genes, proteins, or anatomical structures. As a result of 'descent with modification,' many homologous structures have adapted different purposes. List three anatomical structures in vertebrates that are homologous but have different functions.

Key Concepts

Homologous Structures

Homologous structures are anatomical features in different species that share a common ancestry, even if they serve different functions. For example, the forelimbs of mammals, birds, and reptiles exhibit similar bone structures, indicating their evolutionary relationship despite their varied uses, such as grasping, flying, or swimming.

Descent with Modification

Descent with modification is a key principle of evolution, suggesting that species evolve over time through changes in their traits. This process leads to the diversification of species from common ancestors, resulting in homologous structures adapting to different environments and functions while retaining underlying similarities.

Adaptive Radiation

Adaptive radiation is the evolutionary process where organisms diversify rapidly into a variety of forms to adapt to different environments. This phenomenon often results in homologous structures that have evolved to fulfill distinct roles, such as the varying limb structures in vertebrates that have adapted for different modes of life, like running, swimming, or flying.