Briefly state the problems that animals faced in their adaptation ...

[viki]

Briefly state the problems that animals faced in their adaptation to land. What will be an ideal response?

Question 2

Describe the evolution of fish in the Paleozoic. What will be an ideal response?

[nixon_s]

Answer to Question 1

Because animals evolved in a moist environment, they had to adapt to the drying effects of the
atmosphere, so they had to develop an outer skin covering for protection. They also had to develop a
means to extract oxygen from the atmosphere rather than from water. Because animals need mobility
to find food, they also had to develop a means of locomotion, and a skeletal structure for support
against gravity. Finally, their reproductive system had to combat the problems of desiccation of
unprotected eggs

Answer to Question 2

The most primitive vertebrates were the jawless fish, the ostracoderms. They had poorly developed
fins, an external covering of body armor, and were extinct by the end of the Devonian. Jawless fish
could only feed on detritus, but jawed fish, the acanthodians and placoderms, could chew food and
become active predators. Acanthodians appeared in the Lower Silurian with large spines, scales
covering much of the body, and reduced body armor. Placoderms evolved during the Late Silurian and
had considerable variety.

[viki]

Thank you

[nixon_s]

Happy to help you