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Artificial Selection

Artificial Selection. By: Thomas Philip. What is Artificial Selection?. It is a selective pressure exerted by humans on a population in order to improve or modify particular desirable traits. -. How does it affect us. Do any of you in the class have a pet?

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Artificial Selection

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  1. Artificial Selection By: Thomas Philip

  2. What is Artificial Selection? • It is a selective pressure exerted by humans on a population in order to improve or modify particular desirable traits. -

  3. How does it affect us • Do any of you in the class have a pet? • If you do the chances are that your pet has been through artificial selection when the dog was bred.

  4. Artificial Selection • Breeders have bred dogs with certain characteristics so that the offspring will have those characteristics. • If a dog is born with an undesirable trait then the breeder will not breed that particular dog. • The breeder will breed the ones with the desirable traits. • This will ensure that over time the breed will only contain the desirable traits.

  5. For example • Wolf • Dog • Golden retriever • Lab • This is what happened over many generations with artificial selection.

  6. What is the difference between Artificial & Natural selection? “The only difference between natural selection and artificial selection is whether the difference in reproductive success is driven by naturally occurring processes, or whether the selection is imposed by humans.” The chances are that this cow is not from natural selection but rather bred for some desirable traits through artificial selection.

  7. Natural Selection • Natural Selection occurs naturally in the wild. • Traits are passed on by the animals who have the most offspring. • This usually occurs by the animals that survive the longest due to some trait that allows them to survive longer than one without the trait.

  8. Charles Darwin’s theory • His theory was that, over time a species would change so that it would be more efficient in the wild. • The longer a particular animal survives, the more offspring it will likely have passing on its more desirable genes.

  9. For example: • Male Animal 1 can eat nuts, while Male Animal 2 can eat nuts and leaves. • Over time if something occurs where there are only leaves available to eat, Animal 2 would likely survive longer and produce more offspring. • Over time the offspring would develop into two groups, those who eat leaves and nuts and those who only eat nuts. • Natural Selection would occur by allowing those who could eat both nuts and leaves to continually survive longer and produce more offspring. • The trait of only being able to eat nuts would eventually no longer exist. • It would take many generations for this to occur.

  10. Example 2 • However, this can only happen within a species where the genes are compatible. • Natural selection can only occur when reproduction happens and hence only occurs within a species.

  11. Do you understand? • Put a check mark in this box ☐ if you do • Great you understand!!!

  12. THE END

  13. References • Biology 11 text book • http://ncse.com/creationism/analysis/artificial-vs-natural-selection (definition on natural selection) • My mom

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