MicroEvolution

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MicroEvolution

• HS Bio Work Sample
• Spring 2013

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Learning Target

• I can explain the sources and significance of
  genetic variation.
• I can explain the sources of genetic variation.
• I can explain the significance of genetic
  variation.

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What is Micro-Evolution?

• Micro, meaning small
• Evolution, meaning change over time
• So, microevolution has something to do with
  small changes over time?

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What is Micro-Evolution?

• Well, yes!
• We tend to think of evolution as occurring at the
  organism level, but in order for this to happen,
  changes must occur at a much smaller level the
  genetic level.

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The Genetic Basis of Evolution
Genotype

• For evolution to occur, inherited genetic
  differences must at least partially account for
  phenotypic differences.

Phenotype
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What are the sources of Genetic Variation?

• Mutations!
• Mutations are the ultimate source of variation,
  and are thus the raw material of evolution.
• If there were no variation, then there could be
  no evolution.

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What causes mutations?

• Environmental Agents

• Mistakes in Duplication

• DNA damage from environmental agents
• UV light (sun)
• nuclear radiation
• chemicals agents

• Mistakes that occur when a cell copies its DNA in
  preparation for cell division.

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Do we need to review the structure function of
DNA?

• What purpose does DNA serve in the cell? (Why do
  our cells even need DNA?)
• Information Storage
• What are the two main structural components of
  DNA?
• Phosphate sugar backbone
• the nitrogenous bases
• What five letters are used to spell out
  organismal genomes? Which letters relate to DNA,
  which relate to RNA?
• DNA A, C, G T
• RNA A, C, G, U

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Mutations by Environmental Agents
OR
Cutting of DNA sequence
Change in DNA nucleotide
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Mutations during Duplication
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You awake out there?

• If you could have any super power what would it
  be?

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Some common mutations

• What do these all have in common?

• Chin Dimples
• Lactose intolerance
• Colorblindness
• Pattern Baldness
• Heart Disease
• Diabetes
• Stroke
• Sickle Cell Anemia
• Etc

• They are caused by a unique change in human gene
  sequence, or genome.
• They are inherited from ones parents.
• Generally, they do not negatively influence the
  afflicted individuals chance for reproduction.

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Check for understanding

• Ive discussed two sources of mutation, what was
  one?
• Ive discussed two sources of mutation, what was
  the other?
• Which source of mutation do you think is more
  common?
• Which source of mutation do you think is more
  deleterious (causing harm or damage)?

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Why is genetic variation important?

• Remember mutations are the raw materials for
  evolution
• AND mutations lead to genetic variation
• SO without genetic variation there is not
  evolution!
• But, what is genetic variation?

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What is genetic variation?

• Genetic
• from Ancient Greek genetikos, "genitive" and from
  genesis, "origin
• Of or related to genes, genetic makeup, and
  heredity in living organisms
• Variation
• In Biology marked difference or deviation from
  normal or recognized form, function, or
  structural characteristics
• Genetic Variation
• Varying characteristics in a the genetic makeup
  of a species
• (as a result of genetic mutation)

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But why was genetic variation important?
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Lets break it down
WARNING from this point forward I will being
using the words variation and diversity as
synonyms (like they mean the same thing)

• Genetic Diversity
• Total variety of genetic characteristics in a
  species
• Species Diversity
• Diversity of within an ecological community
• Biodiversity
• The variations of life forms in an ecosystem.
• Ecosystem Diversity
• Variety of species that inhabits the planet

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So what youre saying is

• Mutations lead to genetic diversity...
• Genetic diversity leads to species diversity
• Species diversity leads to biodiversity
• Biodiversity leads to ecological diversity
• But, have I answered the question
• Why is genetic variation important?

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Youre all still awake arent you???

• As a planet, we grow and eat a lot of corn and
  corn products (were talking 324 million ton in
  2010 alone). Currently the majority of corn
  grown in the USA is one species, Zea mays. Say
  some nasty infectious disease decided to start
  eating our corn monocrop
• how would that affect your life?

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Just a few examples of surprising
places where you can find
corn ingredients

• Toothpaste sorbitol
• Salad Dressing high fructose corn syrup
• Gum HFCS, sorbitol, or maltitol
• Make Up starch (filler)
• Milk corn fed cows Vit D
• Shampoo ascorbic acid
• Diapers cornstarch
• Soda HFCS caramel color
• Envelope Glue nitrocellulose glue
• Perfume Cologne grain alcohol
• Aspirin cellulose microcrystalline

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Check In-

• How does corn play a role in your life?
• How would your life be affected if the corn crops
  in the US were to be infected?
• Why is genetic variation (aka genetic diversity)
  important?

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Why is genetic variation important?

• Genetic diversity plays a very important role in
  adaptability and survival of a species!
• When a speciess environment changes, slight gene
  variations are necessary to produce changes in
  that organisms such that enables it to adapt and
  survive.

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How does this relate to our good friend C.
sweetus?

• What evidence is there that variation exists
  within the C. sweetus population?
• Why are some variations inherited and others
  eliminated?
• How do variation, selection, and time fuel the
  process of evolution?