Darwin Postulates
An explanation of Darwin's 4 main postulates on evolution
4 Main Postulates of Evolution by Darwin
Extinction - Not all traits are suited to survive, some will die out because of natural selection.
Differential Survival - External conditions can affect survival
Inheritance - Parents and their offspring look alike.
Extinction & Variation
These birds have variation between them as they adapt to the conditions they are in, but in order to do so, some traits get extinct in order for them to survive in their environment. If a bird is not able to adapt, it will get extinct.
Differential Survival
The mammoth got extinct millions of years ago because of the external conditions it faced, such as the Ice Age.
Inheritance
This photograph demonstrates the gene inheritance that the mother passed down to her daughter.
Variation
Selon Darwin, variation is essential for survival, without variation, a species will not be able to have a competitive advantage towards the other species that are out there.
Extinction
After some time, there commences to be a struggle for existence. If one wants to continue living, it will have to fight, if it is not able to do so sufficiently, a species will get extinct with time.
Differential Survival
The traits that are fittest for survival increase their frequency in each organism, those species that do not develop the traits necessary will slowly die out.
Inheritence
All organisms inherit traits from their parents. That is why the majority of times, a mother and her offspring will look alike. In evolution, the inheritance is done through a selective process that occurs in order for the survival of the organism.
Bibliography
Evolution: Frequently Asked Questions. (2016). Pbs.org. Retrieved 4 April 2016.
Genetic inheritance follows rules :: DNA from the Beginning. (2016). Dnaftb.org. Retrieved 4
April 2016.
Pujari, S.(2014). 4 Main Theories of Evolution (explained with diagram and tables) | Biology. YourArticleLibrary.com: The Next Generation Library. Retrieved 4 April 2016.
Variation and Classification : Revision, Page 5. (n.d). Bbc.co.uk. Retrieved 4 April 2016.