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Natural Selection and Evidence for evolution

Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift.
What is Natural Selection?
The process by which Random evolutionary changes are selected for by nature in a consistent, orderly, non-random way.

Two elements of natural selection include:
Descent with Modification and Common Descent.    

What is Descent with Modification:  
The fact that the parent produces offspring and that those offspring behave slightly different from the parent and from each other. These differences are due to random genetic variations. 

What is Common Descent: 
The idea that all living organisms come from a common ancestor thus relating with one another.

Who discovered Natural Selection? 
It was discovered by Charles Darwin in-between 1809- 1882. Charles Darwin was a naturalist and he was intrigued with Common Descent.   

When was Natural Selection discovered?
It was not until Darwin was 50 years old, in 1859, that Darwin finally published his theory of evolution in full for his fellow scientists and for the public at large. He did so in a 490 page book entitled On the Origin of Species.

What did Darwin think of natural selection?
Darwin proposed that Nature its self is capable of selection.
That when parents have offspring nature simply by being difficult to survive decides which organism gets too live and which does not. 

Ex. Red butterfly and yellow butterfly mate and produce two red butterflies and two white butterflies. The butterflies fly to a garden with only white flowers, the white butterflies are more advantageous at surviving than than the red ones as the white butterflies will camouflage with the white flowers making themselves less visible to predators.
EX. 
In this image you see how natural selection came in handy. The Giraffes with the longer necks were the only ones able to to reach food from the tall trees. The giraffes with the smaller necks could not reach for the food on the tall trees so they starved until they died. As a result,  the Giraffes with the longer necks were naturally selected to survive and pass on their traits to their offspring who will inherit the parents long necks.

What are evidence of evolution?
1) Fossil  evidence: Remains of ancient organisms
2)  Anatomical structures: (Similar body parts)
  •  Analogous structures Ex. The wings of a fly, a moth, and a bird are analogous because they developed independently as adaptations to a common function—flying.
  •  Homologous Structures Ex.
3) Molecular: Evidence with DNA, RNA, ATP
4) Embryological: Similar embryos from one species to the next. Ex
In this image you see how the embryos of different organisms are very identical however they are different. This shows that we evolved from a common ancestor since we all share a similar tail that soon will develop into a different organism.





















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