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On the Origin of “New” Species

On the Origin of “New” Species. Can Evolution and Natural Selection explain how entirely new species might originate?. Natural Selection – review:. Genetic variation within populations. Overproduction of offspring. Competition within populations.

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On the Origin of “New” Species

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  1. On the Origin of “New” Species Can Evolution and Natural Selection explain how entirely new species might originate?

  2. Natural Selection – review: • Genetic variation within populations. • Overproduction of offspring. • Competition within populations. • Successful reproduction by best-adapted individuals. • SURVIVAL OF THE FITTEST!

  3. So Natural Selection can explain how species change slowly and gradually over time.But does it explain how entirely NEW speciesmight arise?

  4. One explanation - SPECIATION.It works like this: • Separation or isolation – when populations become broken up, and they can not mate between them. • Adaptation – through natural selection, the new populations adapt to their different environments, and follow their own evolutionary paths. • Division – the populations eventually differ enough to be new distinct species, which can no longer interbreed

  5. It helps explain how there can be so many species, such as all the different species of salamanders in California.(Click on the image for a short video about the salamanders of California.)

  6. It also might explain what Darwin saw at theGalapogos Islands.

  7. Reasons why populations get separated: • Rivers • Lakes • Canyons • Mountain ranges • Volcanic activity • Drifting continents • Changing climate • Can you think of others?

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