Explain how the world would be different if C4 plants and CAM plants had not evolved.

Answer 1

Since this is not my area of expertise, I searched Google under the key words "C4 CAM plants" to get these possible sources:

http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm
http://www.biologie.uni-hamburg.de/b-online/e24/24b.htm
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/C4plants.html
http://en.wikipedia.org/wiki/C4_carbon_fixation
(Broken Link Removed)

You can use the information from these and other sources listed to give your explanation. In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.