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Variation and Natural Selection Notes Mutations Variations Natural Selection Adaptations Selective Breeding How Does All of This Fit Together? Evolution Charles Darwin
Variation and Natural Selection Notes
Mutations
Variations
Natural Selection
Adaptations
Selective Breeding
How Does All of This Fit Together?
Evolution
Charles Darwin
Charles Darwin
Scientist during the 1800’s that traveled around the world making observations of nature.
Darwin discovered from his travels that organisms have structural characteristics that enable them to live in their environment – Adaptations!
Background Information
Variation and Natural Selection Notes
Darwin’s Finches
As Darwin was observing birds on the Galapagos Islands, he discovered that there were many variations of one kind of bird – the Finch.
Variations are differences in form of an organism within the same species or group.
Background Information
Variation and Natural Selection Notes
Darwin’s Finches (Continued)
These birds that would later become nicknamed as “Darwin’s Finches” proved that organisms adapt to live in their environment.
Each of Darwin’s Finches have a beak that is specifically designed to eat the type of food that is available in its environment.
Background Information
Variation and Natural Selection Notes
Darwin’s Finches (Continued)Each one of these Finches was found on a different Galapagos Island. This illustration shows how various Finches adapted to eat the type of food available to them.
Background Information
Variation and Natural Selection Notes
How Do Adaptations Come About?
How Do Adaptation Come About?
Variation and Natural Selection Notes
Mutations
A mutation is where there is a randomchange in genetic information in an organism.
Mutations can be good and they can be bad.
How Do Adaptations Come About?
If a mutation is good, it will help and organism to live.
If a mutation is bad, it will often cause the organisms to die.
Variation and Natural Selection Notes
Mutations
Good or Beneficial Mutations
Below is a picture of a Black Jaguar (Left). This color mutation is good because it helps the Jaguar to hunt at night, blending into the night time landscape.
How Do Adaptations Come About?
Variation and Natural Selection Notes
Mutations
Bad or Harmful Mutations
Below is a picture of a two headed calf . This type of mutation is bad because the animal is not able to survive.
How Do Adaptations Come About?
Variation and Natural Selection Notes
Variations
Good mutations lead to variations.
When mutations are good, the organism survives to pass the mutation on to it’s offspring. As more and good mutations are passed on, more variations of a species become present as in these parakeets below.
How Do Adaptations Come About?
Variation and Natural Selection Notes
Natural Selection
Mutations which lead to variations also lead to natural selection.
Natural selection occurs when good mutations are passed on to offspring.
How Do Adaptations Come About?
Natural selection is often referred to as “Survival ofthe Fittest”. Organisms that have “stronger” mutations or characteristics survive and the organisms that have “weaker” characteristics die.
The organisms with the stronger characteristic are able to pass their stronger characteristics on to their offspring. The organisms with the weaker characteristics die and are unable to pass their weaker characteristics on.
Variation and Natural Selection Notes
Natural Selection Example
How Do Adaptations Come About?
Variation and Natural Selection Notes
Natural Selection Example (Cont.)
How Do Adaptations Come About?
Variation and Natural Selection Notes
Natural Selection Example (Cont.)
How Do Adaptations Come About?
Variation and Natural Selection Notes
Adaptations
Over very long periods of time, the goodmutations that get pass on and on over several generations become known as adaptations.
How Do Adaptations Come About?
Adaptations take hundreds, thousands, or even millions of years to come about.
If an organism is not able to adapt, it will die. If an entire species is unable to adapt, the whole species will die and become extinct.
Variation and Natural Selection Notes
Selective Breeding
Selective breeding is when animals are bred on purpose to bring about desired traits.
How Do Adaptations Come About?
Below is a picture of a horse (left) and donkey (middle) and a mule (right). When a horse is bred with a donkey a mule is produced. A mule has the strength of a horse and the sure footedness of a donkey.
Variation and Natural Selection Notes
Selective Breeding
Selective breeding is when animals are bred on purpose to bring about desired traits.
How Do Adaptations Come About?
Below is a picture of a horse (left) and donkey (middle) and a mule (right). When a horse is bred with a donkey a mule is produced. A mule has the strength of a horse and the sure footedness of a donkey.
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