Evolutionary Theories

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Evolutionary Theories
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• 1. Describe 1 of Lamarcks hypotheses
• 2. Are all of Lamarcks hypotheses currently
  supported?
• 3. List 2 observations Darwin made on his voyage
  on the Beagle
• 4. In what way did Lyell influence Darwin?
• 5. In what way did Malthus influence Darwin?

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Darwins journey (continue this after the reading
quiz)

• Charles Darwin (1809-1882) sailed on the HMS
  Beagle in 1831
• Observed huge diversity
• 2 questions
• Where did all of these new species come from?
• Why have so many disappeared?

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Darwins evidence and inferences

• 1. All species produce far more offspring than
  required just to replace parents. This would
  result in exponential growth if populations were
  not limited. ("Essays on Population" by Thomas
  Malthus)
• 2. Populations do not, however, increase
  exponentially. They generally remain stable in
  size.(Field observations)
• 3. The resources in the environment are
  limited. (Field observations)

• 1. Because of the limited resources in the
  environment, there is competition among
  individuals. Only a small fraction of the
  individuals born can survive.

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Darwins evidence and inferences

• 4. There is variation within species and
  populations. Some individuals possess
  characteristics that are better suited to the
  environment than others. (Field observations)
• 5. Most physical, and some behavioral
  characteristics are inherited.(Breeding
  experiments with pigeons. "Artificial
  selection")

• 2. Those individuals with the best
  characteristics for the particular environment
  will do a better job of producing and providing
  for offspring than will others with less "fit"
  characteristics.

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Darwins evidence and inferences

• 6. Geologic processes are very, very slow.
  (Principles of Geology by Charles Lyell, work by
  Hutton, as well as Darwin's own studies of
  geology)

• 3. The earth must be very, very old. Over very
  great periods of time, "good" characteristics
  have time to accumulate and less fit ones have
  diminished.

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Reading quiz 8-23/24 (have timeline and
assignment sheet at your desk ready to be stamped)

• 1. Define adaptation
• 2. Define natural selection
• 3. Is natural selection the same thing as
  evolution? Explain.
• 4. List 2 of Darwins points about his theory of
  evolution

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Reading quiz 8-23/24

• 1. Define adaptation
• Inherited trait that provides a selective
  advantage (increases fitness)
• 2. Define natural selection
• Differential rate of reproduction (or survival of
  the fittest organisms)
• 3. Is natural selection the same thing as
  evolution? Explain.
• NO! Evolution refers to changes of a population
  over time. Natural selection is the mechanism
  that can drive evolution
• 4. List 2 of Darwins points about his theory of
  evolution
• Variation within a species exists, some species
  are better suited to survive, favorable traits
  (adaptations) tend to spread in a population,
  living species evolved from organisms (descent)

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Natural Selection

• There is variation in all species
• Some variation better adapted for the environment
  than others
• Natural selection (survival of the fitter)
  Individuals with characteristics better adapted
  for the environment will survive and have more
  viable offspring than non adapted individuals.

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Lamarcks evidence and inference

• Comparisons between current species and fossils
  lines of descendents

• Use and disuse
• Inheritance of acquired characteristics

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What exactly is a theory?

• Explain which picture describes Lamarcks view
  and which pictures describes Darwins view.

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Reading quiz 8-25 (pass SG 4 and assignment
sheet to the center. Natural selection lab will
be collected at the end of class)

• 1. Define a vestigial structure
• 2. Define a homologous structure
• 3. Give an example of a homologous structure
  (description, not picture)
• 4. Describe how proteins can be used to show
  relationships among species
• 5. What is 1 limitation of using proteins to
  compare species

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Evidence for evolution
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Evidence for evolution

• Homologous structure Provides evidence for
  common ancestor (note Humans did NOT evolve from
  apes, but rather a common ancestor
• Vestigial structures
• Embryo similarities
• Biochemical similarities

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Reading quiz 8-28/29

• 1. According to the most current scientific
  evidence, how old is the earth?
• 2. We have found fossils of fish and amphibians.
  What did Darwin predict would eventually be
  found?
• 3. Define a fossil
• 4. List 2 ways fossils can form

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Forming a deduction

• Remember these terms
• Hypothesis, experiment, prediction
• A deduction combines all three. It is a very
  formalized way to guide an experiment.
• IF hypothesis AND experiment THEN prediction
• We are interested whether males or females are
  better at biology
• IF _____ AND ___ THEN ___ .

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Fossils

• Remains or impressions of organisms preserved,
  either in tar, sap, sedimentary rock or other
• Are the remains of all organisms preserved?
• Do scientists have all of these remains?
• What can the fossil record tell us?

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How do species arise?

• Must be reproductively isolated. This develops
  from
• Behavioral isolation
• Geographic isolation
• Temporal isolation

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Darwins finches
Founders arrive
Separation of population
Variation arises
Reproductive isolation
Ecological competition
Continued evolution
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New species case study

• You have just discovered 2 new populations of
  birds living in the Amazon Rain Forest. Although
  they look the same, they seem to sing different
  songs. You first want to know whether these 2
  groups are different species or not. How do you
  decide?
• You find out that they are separate species.
  Propose an explanation for how this speciation
  occurred. Be creative and use all the vocabulary
  learned in class, evolution natural selection
  speciation, etc.

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Reading quiz 8-30/31

• 1. Define reproductive isolation
• 2. Define punctuated equilibrium
• 3. List 2 points of Darwins theory of evolution
  (natural selection)
• 4. Define speciation

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Reading quiz 8-30/31

• 1. Define reproductive isolation
• When 2 groups of organisms cannot interbreed
  (reproduce with each other)
• 2. Define punctuated equilibrium
• Theory in which periods of rapid evolution is
  separated by periods of little/no change
• 3. List 2 points of Darwins theory of evolution
  (natural selection)
• Variation within a species exists,
  overpopulation, some species are better suited to
  survive, favorable traits (adaptations) tend to
  spread in a population, living species evolved
  from organisms (descent)
• 4. Define speciation
• The process of forming new species

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Another example of evolution

• Bacterium Mycobacterium tuberculosis infects
  individuals and causes the lung disease TB

Antibiotics created to kill the bacteria
New strains (variations) appeared. How?
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Another example of evolution

• Bacterium Mycobacterium tuberculosis infects
  individuals and causes the lung disease TB

Antibiotics created to kill the bacteria
New strains (variations) appeared. How?
A change randomly occurs in the bacteria
Variations exist
Non resistant bacteria die
Antibiotic resistant strain thrives!
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Patterns of evolution jigsaw

• Topics
• Punctuated equilibrium (282)
• Adaptive radiation (Divergent evolution) (handed
  out)
• Convergent evolution (307)
• Coevolution (handed out)
• First go through topic with group. Use textbook
  and study guide. Takes notes on your discussion.
  UNDERSTAND YOUR TOPIC!
• Create a poster to visually display your topic.
  This should have the topic title, picture(s), and
  key points.
• You will rotate explaining your topic to others
  and listening to others explain their topic. TAKE
  NOTES!

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Practice essay question

• Support the following statement by clearly
  defining terms, explaining relationships, and
  giving examples. The evolutionary theories of
  Lamarck and Darwin differed, yet had
  commonalities.

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Rubric

• Does the response
• Describe the following points (inferences) about
  Darwins theory variation within species,
  competition, survival of the fittest organisms,
  inheritance of adaptations
• Describe the following points (inferences) about
  Lamarcks theory use and disuse, inheritance of
  acquired characteristics
• Clearly states differences in these descriptions
• Clearly states commonalities in these
  descriptions
• Gives an example of each
• Does the response
• Use the following format IF ___ AND ___ THEN
• Provides a tentative, testable explanation after
  IF
• Provides a general description of the lab after
  AND
• Provides a measurable prediction after THEN (such
  as more prey will survive or of prey living)

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How do I study?

• Study frequently, differently, and actively
• You are given the opportunity to succeed and get
  any grade you want. It is up to YOU to do this
  and earn your grade
• What NOT to do
• Only study the night before or study not at all
• Simply reread information (textbook, etc.)
• Study in only one way
• What TO DO
• Review notes and work EVERY day, and even more
  DAYS before an exam
• While reviewing study guide, labs, worksheets,
  and textbook, keep asking yourself do I
  understand this and keep writing down notes,
  making outlines, answering questions
• Do different things. Flash cards, end of the
  chapter questions, draw out diagrams
• Study with a group, attend review sessions, see
  ME for help!

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How to study

• First assess yourself (be metacognitive)
• For each study guide question, mark it with a
  , v, or
• Focus more on your () and (v) questions. Use
  study guide and notes a primary reference
  (textbook as last resort).