Final answer:
The terms 'descent with modification' and 'common descent' are both fundamental to the study of evolution. 'Descent with modification' refers to the idea that organisms evolve from a common ancestor but undergo changes over time, resulting in new species with different characteristics. 'Common descent' suggests that all living organisms share a common ancestor and can be traced back to a single origin.
Step-by-step explanation:
The term 'descent with modification' and the concept of 'common descent' are both fundamental to the study of evolution.
'Descent with modification' refers to the idea that organisms evolve from a common ancestor but undergo changes over time, resulting in new species with different characteristics.
On the other hand, 'common descent' suggests that all living organisms share a common ancestor and can be traced back to a single origin.
For example, humans and apes have a common ancestor, but over time, they have undergone modifications that have led to their distinct characteristics.
This concept is supported by evidence such as similarities in genetic codes, anatomical structures, and the fossil record.