4. DNA sequence comparison
5. Random mutations
Amphibia is the class of vertebrates which is considered to be the first to develop lungs. This allowed amphibians to live successfully on land as terrestrial organisms. Ichthyostega was the first primitive amphibians with nostrils and lungs. Amphibians adopted themselves to live on land with developed lungs.
Answer:
coevolution
Explanation:
Coevolution refers to the process where two or more species modify each other's evolution via natural selection. Darwin mentioned how insects and flowering plants could coevolve by reciprocal evolutionary modifications. Coevolution has firstly been associated with mutualism between species including, for example, birds and flowering plants. However, coevolution may also involve host-parasite relationships, such as associations involving parasitic organisms and their sexually reproducing hosts. Finally, there are situations where coevolution involves both parasitism and mutualism (i.e., antagonistic coevolution).