TOPIC: Evolution

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• TOPIC Evolution
• AIM Explain the todays theory of evolution.
• Do Now Sit next to your 6 oclock partner for
  the Genetics Review on the next slide.
• Take out Selective Breeding ISN.
• HW Study for tomorrows genetics test!

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• The R allele represents wrinkled seeds. The r
  allele represents smooth seeds.
• Cross 2 heterozygous parents.
• What percentage of the offspring will most likely
  show the dominant trait?
• 75

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• The illustration traces the development of the
  corgi dog over several generations as a result of
  human activity.
• Identify the technique being used.
• Selective Breeding
• Hybridization

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• One way to produce large numbers of genetically
  identical offspring is by
• cloning.
• fertilization.
• changing genes by agents such as radiation or
  chemicals.
• inserting a DNA segment into a different DNA
  molecule.

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• Many diabetics are now using insulin that was
  made by certain bacteria. The ability of these
  bacteria to produce insulin was most likely the
  result of
• deleting many DNA segments from bacterial DNA
• genetic mapping of bacterial DNA to activate the
  gene for insulin production
• inserting a portion of human DNA into the
  ring-shaped DNA of bacteria
• using radiation to trigger mutations

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• Review
• Explain the theory of Natural Selection.
• Explain what Darwin meant by the term
  overproduction.
• Explain what organisms compete for and what the
  result of competition is.
• Explain what Darwin says about variation.
• Describe Survival of the Fittest.
• Describe speciation.

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Sources of genetic variation in a species

• Mutations (changes in DNA)
• Sexual Reproduction
• Genetic engineering
• Selective breeding

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• Migration moving into or out of an area

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Rate of Evolution
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1.Gradualism
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• Evolution occurs SLOWLY CONTINUOUSLY through
  time

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2. Punctuated Equilibrium
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• Sudden changes in a species after long period of
  no change

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• Ex Many bacteria have evolved resistant to
  certain antibiotic

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http//www.youtube.com/watch?vzjR6L38yReE
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Punctuated Equilibrium Today

• Penicillin has been in use since 1943. It
  originally came from the fungus Penicillium.

• 1947 Species of bacteria that cause pneumonia
  and other infections already had developed
  resistance to the drug.

• By the 1990s, several disease-producing bacteria
  had become resistant to penicillin and many other
  antibiotics.

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• When penicillin was used to kill bacteria, those
  with the penicillin-resistant variation survived,
  reproduced, and passed this trait to their
  offspring.

• Over a period of time, this bacteria population
  became penicillin-resistant.

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• BOTH THEORIES SEEMED TO HAVE OCCURRED DURING
  EARTHS HISTORY

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• Those that reproduce at a very fast rate
• Ex bacteria, insects

Which organisms have evolved quickly?
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What can cause extinction?

• Very little variation in a species
• major environmental change
• adaptation no longer favorable
• all organisms die extinction

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• Which population of organisms would be in
  greatest danger of becomingextinct?
• A population of organisms having few variations
  living in a unchanging environment.
• A population of organisms having few variations
  living in an changing environment.
• A population of organisms having many variations
  living in a unchanging environment.
• A population of organisms having many variations
  living in an changing environment.

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• Lets summarize
• Explain the two theories about the rate of
  evolution.
• Identify some sources of variation.
• What will cause a species to become extinct?

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• Which population of organisms would be in
  greatest danger of becomingextinct?
• A population of organisms having few variations
  living in a unchanging environment.
• A population of organisms having few variations
  living in an changing environment.
• A population of organisms having many variations
  living in a unchanging environment.
• A population of organisms having many variations
  living in an changing environment.

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Which statement could best be inferred from the
information in this diagram? (1) Evolution does
not involve gradual change.(2) Evolutionary
changes can result in extinction.(3)
Evolution begins with plants.(4) Evolution
produces organisms that all fill the same
niche.
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• Which statement about the rates of evolution for
  different species is in agreement with the theory
  of evolution?
• (1) They are identical, since the species live on
  the same planet.
• (2) They are identical, since each species is at
  risk of becoming extinct.
• (3) They are different, since each species has
  different adaptations that function within a
  changing environment.
• (4) They are different, since each species has
  access to unlimited  resources within its
  environment.

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• Which concept is not a part of the theory of
  evolution?
• (1) Present-day species developed from earlier
  species.
• (2) Some species die out when environmental
  changes occur.
• (3) Complex organisms develop from simple
  organisms over time.
• (4) Change occurs according to the needs of an
  individual organism to survive.

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• Fossil records indicate that between 80 and 60
  million years ago the structure of the horned
  dinosaur underwent rapid changes separated by
  long periods of stability. This pattern of change
  best illustrates the concept of
• use and disuse
• (2) punctuated equilibrium
• (3) gradualism
• (4) enzyme specificity

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• A key concept in the modern theory of evolution
  explains
• (1) how new organs arise according to the
  needs of an organism(2) how variations occur
  within a species(3) the continued increase
  in the human population(4) the presence of
  asexual reproduction within a species

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• Some scientists suggest that the extinction of
  dinosaurs resulted from sudden global weather
  changes caused by the impact of an asteroid on
  Earth. This event most likely promoted the
  evolution of new species of animals. These ideas
  best support the concept of
• (1) punctuated equilibrium(2) use and
  disuse(3) gradualism(4) geographic isolation

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1. Identify the common ancestor.
2. Identify the species that have become extinct.
   Why did these species become extinct?