Darwin's Four Postulates
Example: All the humans have the same genetic code but variation lets us have different color of eyes, skin and height.
Example: When a horse with running skills passes down those skills to his offspring because of the genetic transmission.
Example: The different types of finches have different beaks because they need them for the different environments and the different types of vegetation.
Example: The extinction of other cavemen because of their lack of intelligence.
Berkeley. (2001, February 10). Introduction to Ecological Genetics. Retrieved April 07, 2016, from http://ib.berkeley.edu/courses/ib162/Week1.htm
Cornell, H. (2010, July 15). Darwinism Refuted.com. Retrieved April 07, 2016, from http://www.darwinismrefuted.com/origin_of_species_01.html
Nedeker, B. (2005, April 30). Charles Darwin. Retrieved April 07, 2016, from http://www.biography.com/people/charles-darwin-9266433
Spieth, J. (2012, October 26). Charles Darwin on Extinction - The role of extinction in evolution. Retrieved April 07, 2016, from http://www.biology-online.org/articles/role_extinction_evolution/charles_darwin_extinction.html