Darwin's Postulate

Jimena Villarreal

The Four Postulate's

(1) the potential for a species to increase in number.

This postulate clearly refers to the importance of evolution. This calls upon variation because the more the species grow the more they vary in genes. Although this postulate seems as something very obvious it is detrimental for evolution and is present throughout every single species of Earth. For instance, HIV in Africa, our species has been victim to aids for many years however although there are a ton of deaths do to it, our population, due to its increase in numbers, doesn't show significant impact in the population. Through generations, our species has learned to survive challenges such as this one and keep growing. The differences in genes allow species to adapt and survive most of the time when encountering changes.


(2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction.

This postulate refers to the inevitable inheritance of genetic variation. This can be seen throughout increases in dominant traits age time goes by, (generations). One clear example of trait dominance is in the bunny simulation that allowed us to see what would happen to a population over 12 generations. In many cases the population of white fur would include brown fur bunnies and if you went to see the family trees you could see the recessive genes and dominant genes being passed down. This simulation backs up Darwin's postulate because it was very clear how through reproduction, mutations were passed down, sometimes it was fur color, sometimes it was teeth size and sometimes it was even tail length.


(3) competition for limited resources.

Since our world consists of renewable and nonrenewable sources there is a lot of competition for the limited ones that our earth possesses. Because of the limitations, the more species reproduce the less availability per resource for each individual. This goes back to survival of the fittest because those who have less or can't obtain the necessary resources to live will eventually die. A clear example of these is the ratio of dogs in Monterrey alone compared to homes. The numbers have increased so much that everyday thousands of dogs are being taken to the pound to put to sleep because there isn't anymore space for them. The competition of resources ensures that only the best-est of each species survive.


(4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

The final postulate we are going to analyze is almost a conclusion of the other ones. It says that organisms with advantageous traits will be the ones to pass their genes towards other generations. For instance the evolution of birds whose ancestors are dinosaurs. They are clearly very different and it has been over millions of years but this is the kind of things that allows us to understand adaptation and gene differentiation which explain why some traits are not passed down through generations.


Sources:

Garner, P. (August 1, 2012) "Introduction to Ecological Genetics." Retrieved April 5, 2016, from http://ib.berkeley.edu/courses/ib162/Week1.htm


Gittleman, J. (October 2015). Extinction | biology. Retrieved April 05, 2016, from http://global.britannica.com/science/extinction-biology


Johnsen, Z. (2016). Fading Puppy Syndrome. Retrieved April 5, 2016, from

http://www.all-about-goldens.com/fading-puppy-syndrome.html


Pianka, Eric. (2008) Convergent Evolution. Retrieved April 5, 2016, from http://www.zo.utexas.edu/courses/THOC/Convergence.html