Final answer:
Vertebrates adapted to terrestrial life through limb modifications for movement, development of lungs for breathing air, and skin changes for moisture retention and cutaneous respiration. The internal fertilization mechanism was also crucial for their successful reproduction on land. These adaptations were essential as they transitioned from aquatic to terrestrial lifestyles.
Step-by-step explanation:
Vertebrates conquered the terrestrial environment through major adaptations, including limb modifications, the development of lungs for breathing atmospheric oxygen, and changes to their skin, allowing them to resist dehydration and survive outside of water.
For instance, amphibians, the first land vertebrates, adapted to life on land through significant internal and external changes. They evolved from gill-breathing aquatic forms, developing lungs for respiration on land. Their fins transformed into limbed appendages, helping them with terrestrial locomotion.
Additionally, their moist skin developed special adaptations to allow cutaneous respiration, absorbing oxygen and releasing carbon dioxide directly through the skin, supplemented by mucus glands for maintenance of moisture.
These evolutionary milestones allowed early vertebrates like amphibians to thrive on land despite being initially born in water, paving the way for the diverse range of terrestrial vertebrates we see today.
Furthermore, vertebrates developed internal fertilization mechanisms to adapt to the terrestrial lifestyle. This advancement was crucial for reproduction on land, where external fertilization methods used in water would not be effective.
Over time, as plant life expanded creating diverse ecosystems, vertebrates continued to evolve, leading to the emergence of different lineages such as synapsids and mammals, reptiles, dinosaurs, and birds.