Darwin's Four Postulates

Daniel Benavides Martinez P3

Variation in the Population

Even though that the animals in the population can be very similar to each other, they all have differences. Whether they are major or small differences, the differences can be found. The thing is that difference is needed for the Natural Selection process to take place. The process of natural selection cannot happen out of thin air, they need to have differences, weaknesses and strengths for it to take place. Natural selection really is: The fit will survive and the weak will die. Why does this have to happen? Why keep the weak? The weak die for the strong to keep reproducing and continue to make the genes even stronger than they were. What Natural selection is trying to do is for only the best of the best to continue, and to keep reproducing and continue to evolve to become better. What mostly changes through generations are the genes, the genes are what help the living organisms evolve and be able to survive and get better qualities, whether they are physical or mental.

Heritable Variation

Lets face it, we can all see how similar we are to our parents and even sometimes our grandparents. This is also the case with any living thing in the world. Most of the characteristics that you have as an offspring have been herited by somebody before you, whether it was your parents or grandfather or whatever. This is what Darwin is trying to show us. The characteristics of a living thing are not just created, they are herited by somebody before you, they are not just created all of a sudden. The only way new characteristics are created when they are evolved (become better). What the producers are trying to do (summarised) is to make their genes even better and stronger for them to be able to pass them to their offpsrings.
Big image

Selection

You may be asking yourself: How does selection happen? How does it work? Well let me explain, Selection is something that works with the environment, in other words, tests the animals survivability in the environment he is located. What the environments role do is to determine which genes of the animals are strong and which ones are weak, here they are able to determine which one should be evolved and which one will be discarded. What does the environment do exactly? Well they test the animal, they see what climate they can tolerate and if they aren't able to do it the animal will be able to evolve for them to finally be able to tolerate it.

Survival and Reproduction are not Random

To explain what Darwin tried to do i would like to do an example. The example will be about tigers. For example a Tiger has 2 cubs, one of the tigers is born with longer legs than the other one. What is the up side of having longer legs? Well they will be able to gain speed quicker and achieve a higher top speed which helps them hunt. The problem of not having normal or long legs would be that they would not be able to catch their pray and slay them with their powerful canines. So many physical characteristics are based on the survivability of the animal. They need to have supreme characteristics and evolved that will help them do their "job" correctly. Why can this caused selective reproduction? Well the tiger with shorter legs will have a very big problem when he has his own offspring, he will not be able to catch the prey to feed them or even protect them. While the tiger with long legs will have the ability to do all of the duties necessary to take care of his offspring, that is why selective breeding happens, they need to be ready to do it and be capable of doing it, and some aren't.
Big image