The Theory of Evolution: Variation and Adaptation

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The Theory of Evolution Variation and Adaptation

• Chapter 10.1

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2 Minute Quick write

• What is the purpose of life, from a biological
  point of view?

• Bonus Name this sculpture..
• Who sculpted it?
• Have you seen it?

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Within a species, an amazing amount of variation
exists

• Species interbreeding populations of organisms
  that can produce healthy offspring.
• Variation the differences between individual
  members of a population.

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Variation within a species

• Some variations you can see size, color, shape
  of teeth, etc.
• Some variations can not be seen, they are
  biochemical blood type or hormone level.

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Variation within a species

• Some variations you can see size, color, shape
  of teeth, etc.
• Some variations can not be seen, they are
  biochemical blood type or hormone level.

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Variation within a species

• Many variations are genetic, and can be
  inherited.
• They result from mutation and recombination.

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Variation from Mutation

• Most mutations are neutral or harmful
• Some are beneficial in certain instances
• Gray fox in snow
• Light skin in colder climate.

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Variation from recombination.

• Most variation comes from recombination of
  existing alleles.
• During sexual reproduction, alleles recombine 3
  ways
• Independent assortment of chromosomes.
• Crossing over during meiosis
• Random fertilization.

Is the Quagga extinct? It has been bred back.
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Adaptation

• Adaptation an inherited trait that increases a
  populations chance of survival and reproduction
  in a particular environment.

The anteaters snout is an example of adaptation.
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Nichea habitat and the role a population plays
in that habitat.

• Includes where organisms live, what and how they
  eat, how they raise offspring, who their
  predators are.
• Conditions such as space, light, moisture and
  temperature are included.
• When two populations try to occupy the same
  niche, fierce competition arises.
• What are they competing for ?

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10.1 Biodiversity

• Biodiversity The variety and abundance of
  species that make up a biological community.
• Is biodiversity good?
• Change creates advantages for some species and
  disadvantages for others.

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10.1 Biodiversity

• Biodiversity Earth is home to 15 million
  species.
• 99 percent of all types of organisms that ever
  lived are now extinct.
• Change creates advantages for some species and
  disadvantages for others.

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10.1 Biodiversity

• Earths history can be studied using fossils, the
  preserved remains or imprints of ancient
  organisms.
• Scientists who study fossils are paleontologists
• Fossils are found in sedimentary rock

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How are fossils formed?
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10.1 Biodiversity

• Paleontologists dont have a complete record of
  the history of life.
• Soft bodied animals dont make good fossils.
• Fossils are vulnerable to erosion and weathering.
  
• They are hard to find.