m12.    Why are organisms becoming extinct?

Extinction is occurring at an unnaturally rapid rate because of man's interference with nature.  More than 50,000 species per year could become extinct by 2005. For the first time plants are becoming extinct as rapidly as animals.

e10.    Why do organisms become extinct?  

e11.    What types of old-growth forests are there?

g04.    What causes climates to change?

g05.    How are forests of geological importance?

g07.    How did plate tectonics affect the diversity of ecosystems?

g10.   What are earthquakes?

g11.    What is volcanism?

g12.    How are mountains built?

g20.    What is the theory of plate tectonics?