Darwin's Four Postulates

Andrea Arnaud - Biology P4

According to Darwin, the process of evolution is possible because of the following four postulates.

1. Population Growth

The population grows alongside the dominant or advantageous traits. If a specie or a variation of a certain animal has a better chance at survival it will completely out compete other competition and other variations of the animal. It is a cycle that keeps on repeating itself no matter what. There will always be a new advantage and a variation lacking that trait. It is what keeps evolution alive, that said, not every specie has the same survival rate.

2. Inheritance (Mutations and sexual reproduction)

Mutations and dominant traits that are passed generation through generation can be easily magnified by inheritance. Because of how the circle of life works, we will see how the advantageous or dominant traits will magnify in great proportions once a couple of generations start passing by. This is because they simply pose a better chance at survival in their given ecosystem.

3. Competition

The different variations that are passed down generation through generation can create different advantages for different animals. These advantages can help animals get their prey or have a better chance at survival, all depending on the different ecosystems.


There are a lot of variation within the same species, (smaller tails, larger tails, faster animals, slower animals), many different traits that make animals be different as they are. The ones with the most dominant traits tend to start to grow as they are the ones that benefited by these different traits. There will always have to be variation amongst the animals as a whole.


Darwin's Four Postulates. (1992). Retrieved April 4, 2016, from http://ib.berkeley.edu/courses/ib162/Week1.htm

Darwinian Natural Selection. (2008). Retrieved April 4, 2016, from http://bioserv.fiu.edu/ortegaj/CHAPTER3_DARWIN_SPR.pdf

Natural Selection: Darwin's Four Postulates. (2015, February 6). Retrieved April 4, 2016, from https://kiputsc.wordpress.com/2015/02/06/frebruary-6-2015-natural-selection-darwins-four-postulates/