Evolutionary Theories
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1. Describe 1 of Lamarck’s hypotheses
2. Are all of Lamarck’s 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?
Darwin’s journey (continue this after the
reading quiz)
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Charles Darwin (18091882) sailed on the
HMS Beagle in 1831
Observed huge
diversity
2 questions:
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Where did all of these
new species come from?
Why have so many
disappeared?
Darwin’s evidence and inferences
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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)
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2. Populations do not, however,
increase exponentially. They
generally remain stable in size.
(Field observations)
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3. The resources in the
environment are limited. (Field
observations)
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1. Because of the limited
resources in the environment,
there is competition among
individuals. Only a small
fraction of the individuals born
can survive.
Darwin’s evidence and inferences
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4. There is variation within
species and populations. Some
individuals possess characteristics
that are better suited to the
environment than others. (Field
observations)
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5. Most physical, and some
behavioral characteristics are
inherited.
(Breeding experiments with
pigeons. "Artificial selection")
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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.
Darwin’s evidence and inferences
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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)
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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.
Reading quiz: 8-23/24 (have timeline and
assignment sheet at your desk ready to be
stamped)
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1. Define adaptation
2. Define natural selection
3. Is natural selection the same thing as
evolution? Explain.
4. List 2 of Darwin’s points about his theory of
evolution
Reading quiz: 8-23/24
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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 Darwin’s 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)
Natural Selection
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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.
Lamarck’s evidence and inference
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Comparisons between
current species and
fossils: lines of
descendents
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Use and disuse
Inheritance of acquired
characteristics
What exactly is a theory?
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Explain which picture describes Lamarck’s
view and which pictures describes Darwin’s
view.
Reading quiz: 8-25 (pass SG 4 and assignment sheet to the
center. Natural selection lab will be collected at the end of
class)
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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
Evidence for evolution
Evidence for evolution
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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
Reading quiz: 8-28/29
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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
Forming a deduction
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Remember these terms…
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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 ___ .
Fossils
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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?
How do species arise?
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Must be
reproductively
isolated. This
develops from
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Behavioral isolation
Geographic isolation
Temporal isolation
Darwin’s
finches
Founders arrive
Separation of population
Variation arises
Reproductive isolation
Ecological competition
Continued evolution
New species case study
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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.
Reading quiz: 8-30/31
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1. Define reproductive isolation
2. Define punctuated equilibrium
3. List 2 points of Darwin’s theory of evolution
(natural selection)
4. Define speciation
Reading quiz: 8-30/31
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1. Define reproductive isolation
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2. Define punctuated equilibrium
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Theory in which periods of rapid evolution is separated by
periods of little/no change
3. List 2 points of Darwin’s theory of evolution
(natural selection)
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When 2 groups of organisms cannot interbreed (reproduce
with each other)
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
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The process of forming new species
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?
Another example of evolution
Bacterium
Mycobacterium
tuberculosis infects
individuals and
causes the lung
disease TB
Variations
exist
Antibiotics
created to
kill the
bacteria
Non resistant
bacteria die
New strains
(variations)
appeared.
How?
A change
randomly
occurs in the
bacteria
Antibiotic
resistant
strain
thrives!
Patterns of evolution jigsaw
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Topics
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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!
Practice essay question
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Support the following statement by clearly
defining terms, explaining relationships, and
giving examples. The evolutionary theories of
Lamarck and Darwin differed, yet had
commonalities.
Rubric
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Does the response…
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Describe the following points (inferences) about Darwin’s theory – variation
within species, competition, survival of the fittest organisms, inheritance of
adaptations
Describe the following points (inferences) about Lamarck’s 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…
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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)
How do I study?
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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!
How to study
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First assess yourself (be metacognitive)
For each study guide question, mark it with a +, √,
or –
Focus more on your (–) and (√) questions. Use
study guide and notes a primary reference (textbook
as last resort).