Darwin's Four Postulates

Reynaldo Richardson

Postulate I

The first postulate was that there had to be variation in the phenotypes, or the traits, of individuals within the species. Without variation the phenotypes would never change therefore evolution would never occur.

Postulate II

Secondly, in every generation more progeny must be created than what can survive. For every generation that is born not all offspring can survive. This second postulate is very important because animals with higher traits or the organisms who are more adapt are the one's who survive and pass on their traits.

Postulate III

The third postulate, states that the survival and reproduction of individuals is not random. Animals with more better traits, or traits that are more adaptive to the current environment commonly have a better chance of surviving that individuals who don't. Those who have better chances of surviving remain in the population long enough to reproduce more. This is when the individuals with higher traits increases reproduction and eventually the individuals with higher traits or also called the "fittest" will survive and their traits will be passed on. While the individuals with weaker traits will eventually die. This is called "survival of the fittest".

Postulate IV

The last and most important postulate is the one that defines Darwin and what made him earn an important position in the science world. The four postulates states that phenotypic traits had to be heritable. Darwin stated that this traits somehow had to be passed on to future generations but he never discovered how the transfer of genetics worked.


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