Do Now

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Do Now

• 2 minute free write responding to the questions
• What do you know about evolution and natural
  selection? What do you WANT to know?

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Evolution

• Chapter 6
• Period 4
• Ms. Suckow

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Early thoughts about Evolution

• There are millions of different types of
  organisms.
• Included among these organisms are species.
• Species are a group of organisms whose members
  successfully reproduce among themselves.

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Evolution

• The evolution of the horse can be traced back to
  at least 55 million years.

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Theorist Jean Batiste de Lamarck

• French scientist
• In 1809 he proposed one of the first explanations
  as to how species evolved.
• Hypothesized that species evolve by keeping
  traits their parents developed.
• Felt as if traits werent used they would be
  lost.
• Theory of acquired characteristic Dog with
  cropped ears.

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Theorist Charles Darwin

• At the age of 22, Darwin became the ships
  naturalist on the HMS Beagle.
• On a trip to survey the east and west coast of
  South America, Darwin recorded information about
  all the plants and animals during his journey.

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Principals of Natural Selection

• Darwins observation convinced him that
  individuals pass traits most favorable to
  themselves to their offspring, this is known as
  natural selection.
• Natural selection means that organisms with
  traits best suited to their environments will
  most likely survive.

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Darwin identified four factors

• 1. Organisms produce more offspring than can
  survive.
• 2. Variations are found among individuals of a
  species.
• 3. Some variations enable members of a population
  to survive and reproduce better than others.
• 4. Over time, offspring of individuals with
  helpful variations make up more and more of a
  population.

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Adaptation and Variation

• A variation is the appearance of an inherited
  trait that makes an individual different from
  other members of the same species.
• Some differences may be as small as different
  hairlines and as large as fruit without seeds.

• An adaptation is any variation that makes an
  organism better suited to its environment.
• Some variations may be color, shape, behavior, or
  chemical makeup.

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Checking Understanding

• A group of organisms whose members look alike and
  successfully reproduce among themselves is known
  as a(n)______.
• A. Species
• B. Variation

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Answer

• A. Species

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Checking Understanding

• Darwin concluded that individuals with traits
  most favorable for a specific environment survive
  and pass these traits on to their offspring. This
  is the theory of evolution by ________.
• A. Natural Selection
• B. Evolution

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Answer

• Natural Selection

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Checking Understanding

• A(n) _______ is a group of organisms of one
  species that live in an area.
• A. Population
• B. Giraffe

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Answer

• A. Population

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EXIT QUESTION
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Exit Question

• What is variation?
• Give an example of a variation in humans.