Answer:
Common descent is a theory that states that all organisms are descendants of a single common ancestor.
Step-by-step explanation:
Common Descent:
- By definition, common descent signifies the common ancestry of a group of organisms.
- Common descent is an approach to explain the similarities between different organisms.
- The theory of common descent states that all organisms have descended from one common ancestor and therefore, possess some degree of similarity.
- Common descent has helped explain the genetic and structural similarities between two entirely different organisms such as reptiles and birds.
- For example, pentadactyl limbs i.e. limb with five fingers or digits is a highly conserved characteristics of all tetrapods. This indicates common descent with modification.