the respiratory systems of mammals and birds adapted to maximise the extraction of oxygen from air. How has did this happen.

Answer 1

Since this is not my area of expertise, I searched Google under the key words "evolutionary development of lungs" to get these possible sources:

https://www.google.com/search?client=safari&rls=en&q=evolutionary+development+of+lungs&ie=UTF-8&oe=UTF-8&gws_rd=ssl

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

Don't just copy the material. Express the ideas in your own words. Although this will take more time and effort, you will learn more.