Darwin's 4 Postulates

By: Ana Caty Treviño

1. In all species there is heritable variation

-Variations arise purely by chance resulting from random mutations in DNA


-Differences are obvious in many physical characteristics and extend to molecular level

2. In every generation, more offsprings are produced that can survive

-Darwin observed that many more individuals are born than survive


-Some individuals have more offspring than others

3. Survival and reproduction of individuals is not random

Natural selection acts on individuals within a population; however, it is the population that changes over time

Some phenotypic variants are passed on to offspring

Gregory Mendel's theories of inheritance(1865) confirmed Darwin's assumption that certain traits are heritable

APA Sources

Darwin, C. (1859, Jun 3). On the Origin of Species by Means of Natural Selection, 1st edition. Retrieved April 7, 2016, from http://www.esp.org/books/darwin/origin/facsimile/


Gramlich, C. A. (2010, Jan 14). On the Origin of Species by Means of Natural Selection. Masterplots, Fourth Edition, 1-2. Retrieved April 5, 2016, from http://web.a.ebscohost.com/ehost/detail/detail?vid=5&sid=43088fc3-3bc14e85927a2361dc1ddcb4%40sessionmgr4004&hid=4201&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#AN=103331MP424249820000716&db=lfh


Shubin, N. (2013, May 21). Darwin's Theory of Evolution. Retrieved April 7, 2016, from http://www.science4all.org/article/darwins-theory-of-evolution/