Transcript Evolution - Dublin City Schools

Evolution
Genetic change in a
population over time
What are the 3 necessary ingredients for evolution?
• Evolution is a natural phenomenon that will
occur wherever suitable conditions exist
• It’s a genetic change in a population over time
• Is the example below macroevolution or microevolution?
Evidences for Evolution
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Fossils: What is a fossil?
Comparative Embryology
Comparative Biochemistry
Comparative Anatomy
Fossil Evidence
• Preservation in ice
and acid
• Preservation in
amber
• Preserved hard parts
• Petrification
• Molds and casts
• Imprints
Preservation in Ice & Acid
• Organisms are kept from
decaying in ice or strongly
acidic conditions.
• Why are bogs conducive to
preservation and not
decomposition?
Preservation in Amber
• Fossilized
tree sap
Preserved Hard Parts
• Organic materials
in hard parts of
living things
leech out and are
replaced by
minerals in the
surrounding rock
Petrification
• Organic
materials in
tree tissue
leech out and
are replaced by
minerals in the
surrounding
rock
Molds & Casts
• Molds impressions
• Casts 3-D
• Identify the 3 pictures as
molds or casts.
Imprints
• Impressions or
indentations in
rock
Stratification
strata
• What does the root word
“strata”mean?
• How fossils are formed
• Becoming a Fossil
Relative Dating
estimating the age of something compared to something else
Absolute Dating
RadioMetric Dating Video:
http://www.pbs.org/wgbh/evolution/library/03/3/l_033_01.html
• radioactive: decay of nuclei
of unstable atoms half-life
• uranium 238 = 4.5billion yrs
uraniumlead
• C14 up to 40,000yrs
• C14C12 half life 5700
• If a piece of rock is found
with a Lead:Uranium ratio
of 7:1, how old is the rock?
Comparative Embryology
• "ontogeny
recapitulates
phylogeny"
• each embryo has
to repeat the
adult stages of
its biological
predecessors
• Haeckel was a
fraud!
Comparative Biochemistry
• DNA sequence
and protein
molecules
• What is the
adjacent picture
called?
• What is the
name of the
process which
generates it?
Comparative Anatomy
• Homologous
structures
• Analogous
structures
• Vestigial
structures
Homologous Structures
• Similar in design, different in function
• Divergent Evolution offspring of a
common (similar) ancestor diverge b/c
they are adapted by different environments
Adaptive Radiation
process by which
ancestral
species
evolve into a number
of diff species
Analogous Structures
similar in function different in design
• offspring nonrelated
(different) ancestors
converge b/c they
are
adapted
by
similar
environments
• Speed and stealth in
the water 
• Rolling for
defense
What is the name of this animal?
• Echolocation for
feeding in
darkness (Oil
bird and bat)
• Convergent Evol.
• result of geographic
isolation and niches
to be filled
• process by which
different species
evolve similar
structures or
adaptations to
similar (but diff)
environments
Parallel
Evolution
Divergent, Convergent & Parallel Evolution
Make a Venn comparing the 3 types of evolution. 3 facts per group.
• Hummingbird
flowers
• What kind of
evolution do
these flowers
exhibit? Why?
Co-Evolution
• When two different
organisms change
in response to each
other
• How many bees are on
the screen? Write your
answer and then watch
the videos.
Evolution of Camouflage:
Orchard Wasps
Mimicry
Will the REAL stinging insect
please stand up!
How many stinging insects on the screen?
Mimicry only works if there are
more _____________
Vestigial structures
• a structure or organ
that
has
no
apparent use
• if organisms use
the
minimal
amount of E to
survive,why would
they use E to form
a structure that has
no use?
Theories of Evolution
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Empedocles
Aristotle
Linnaeus
Lamarck
Cuvier
Lyell
Wallace/Darwin
Stanley/Gould
Science influences
society, which influences
science.
Lamarck & Acquired Characteristics
• Acquired
characteristics traits
acquired during life
can be passed to
offspring
• Theory of Use &
Disuse what we use
gets larger and what
we don’t gradually
disappears
Natural Selection (Darwin & Wallace)
• Overproduction
• Struggle for existence/
Competition
• Variation within a
species
• Survival of the fittest
problem: how did variations arise?
How does Evolution Really Work
Overproduction
• Thomas
Malthus "Essay
on Principles of
Population"
• geometric/expo
nential
progression (vs
arithmetic)
Gradualism vs Punctuated Equilibrium
Permian Extinction
Speciation
Formation of a new
species (group of
organisms that can
reproduce fertile
offspring) needs:
1. Available niche
2. Genetic Isolation
3. Time
Genetic Isolation
Geographic/allopatric Isolation results from
physical separation
Ecological/sympatric Isolation:
• Mechanical (post/pre zygotic)
• Temporal
• Ethological (behavioral)
• Isolating Lacewing songs
Directional Selection
• Selection against
one extreme
• Fit to be ONE
extreme
Stabilizing Selection
• Selection against
both extremes
• Fit to be
AVERAGE
Disruptive Selection
• Selection against
the average
• It is fit to be BOTH
extremes
• Give a plausible example of each of the 2 types of
speciation.
• Give a plausible example of each of the 3 types of
selection.
• Making a Cladistic: Try the following activity:
http://www.pbs.org/wgbh/evolution/change/family/
Why Does Evolution Matter Now?
• Evolution of Antibiotic Resistance
• Biological Invaders
How Did We Meet the GPS?
SB5. Students will evaluate the role of natural selection in
the development of the theory of evolution.
a.
Trace the history of the theory.
b.
Explain the history of life in terms of biodiversity,
ancestry, and the rates of evolution.
c.
Explain how fossil and biochemical evidence support
the theory.
d.
Relate natural selection to changes in organisms.
e.
Recognize the role of evolution to biological resistance
(pesticide and antibiotic resistance).
References
• Absolute Dating: dig.anthro.niu.edu/anth102/ 01intro/1dating.html
• PBS Evolution Library:
http://www.pbs.org/wgbh/evolution/library/index.html
• Mimicry: http://www.morning-earth.org/Graphic-E/TransfMimic.html
• NOVA: Homeobox Genes