3/23/12- Document what you did on your
DoNow Sheet for today.
Copy & answer on a separate sheet of paper.
1. How do you think you did on yesterday’s test?
2. How long did you study (outside of class)?
3. Did you fully complete the review sheet?
4. What could YOU do to improve your grade?
5. What could we do to help you?
Study over Week 11 Vocab/Copy down Week 12
*Take out EOCT- p9 &10
3/26/12— Take out “Lorenzo’s Oil” Handout &
EOCT p9-10, from Friday.
Turn to pp417-422;
382-386
Read the following
pages…
Be on task when the
bell rings, so we can
listen to
announcements &
finish the movie…
3/27/12—Continue to define Evolution Vocab.
Take out EOCT p9 & 10
• Spontaneous
generation
• Endosymbiotic theory
• Biogenesis
•
•
•
•
Directional selection
Stabilizing selection
Disruptive selection
Natural Selection
After you have finished,
read the following
pages 417-422;
382-386, quietly
Essential Question: What are some
theories about the origin of life on
earth?
EVOLUTION
Today’s principle…
• BIOGENESIS-all living things
come from other living things
17th Century beliefs…
Spontaneous generationliving things could arise from
nonliving things
Experiments by Francesco Redi,
Lazzara Spallanzani, & Pasteur led
to the modern day idea of biogenesis
Redi
Lazzaro Spallanzani
demonstrated that
sealing off the flask
would keep
microrganisms from
forming in the broth.
Pasteur’s Experiment
Alexander Oparin
hypothesized that the gases
in the primitive atmosphere
lead to the formations of
organic molecules and
finally living things.
Early Earth
•
Approximately 4.6 bya
•
Primitive atmosphere
Earth's early atmosphere
probably contained hydrogen
cyanide, carbon dioxide,
carbon monoxide, nitrogen,
hydrogen sulfide, and water.
– Probably no O2
Conditions on the Early Earth
• 4.5 billion years ago
– “Cloud” began to condense = rain
• 4 billion years ago
– Crust and mantle formed
• Primitive atmosphere
– H2, N2, CO, CO2 , probably no O2
– Hot temperatures
Miller and
Urey’s
experiment
tested
Oparin’s
hypothesis.
It recreated
the
conditions of
early Earth.
– Miller and Urey's experiments suggested how
mixtures of the organic compounds necessary
for life could have arisen from simpler
compounds present on a primitive Earth.
• Evidence suggests that 200–300 million
years after Earth had liquid water, cells
similar to modern bacteria arose.
The Puzzle of Life's Origins
– Formation of Microspheres
• In certain conditions, large organic molecules form
tiny bubbles called proteinoid microspheres.
• Microspheres are not cells, but they have
selectively permeable membranes and can store
and release energy.
• Hypotheses suggest that structures similar to
microspheres might have acquired more
characteristics of living cells.
The Puzzle of Life's Origins
– Evolution of RNA and DNA
• How could DNA and RNA have evolved? Several
hypotheses suggest:
• Some RNA sequences can help DNA replicate under the
right conditions.
• Some RNA molecules can even grow and duplicate
themselves suggesting RNA might have existed before
DNA.
• Microscopic fossils, or microfossils, of unicellular
prokaryotic organisms resembling modern bacteria
have been found in rocks over 3.5 billion years old.
• These first life-forms evolved without oxygen.
Free Oxygen
• About 2.2 billion years ago, photosynthetic bacteria
began to pump oxygen into the oceans.
• Next, oxygen gas accumulated in the atmosphere.
– The rise of oxygen in the atmosphere drove
some life forms to extinction, while other life
forms evolved new, more efficient metabolic
pathways that used oxygen for respiration.
Origin of Eukaryotic Cells
• The Endosymbiotic Theory
– The endosymbiotic theory proposes that eukaryotic
cells arose from living communities formed by
prokaryotic organisms.
– About 2 billion years ago, prokaryotic cells began
evolving internal cell membranes.
– The result was the ancestor of all eukaryotic cells.
– According to the endosymbiotic theory, eukaryotic
cells formed from a symbiosis among several different
prokaryotes.
Origin of Eukaryotic Cells
• Endosymbiotic Theory
Ancient Prokaryotes
Chloroplast
Aerobic
bacteria
Nuclear
envelope
evolving
Ancient Anaerobic
Prokaryote
Photosynthetic
bacteria
Plants and
plantlike
protists
Mitochondrion
Primitive Aerobic
Eukaryote
Primitive Photosynthetic
Eukaryote
Animals,
fungi, and
non-plantlike
protists
Origin of Eukaryotic Cells
Aerobic
bacteria
Ancient Prokaryotes
Nuclear
envelope
evolving
Ancient Anaerobic Prokaryote
Origin of Eukaryotic
Cells
Mitochondrion
• Prokaryotes that
use oxygen to
generate
energy-rich
molecules of
ATP evolved
into
mitochondria.
Primitive Aerobic Eukaryote
Origin of Eukaryotic Cells
Prokaryotes that carried out
photosynthesis evolved into
chloroplasts.
Chloroplast
Photosynthetic
bacteria
Primitive Photosynthetic Eukaryote
Reading Assignment
• Read p. 423-428 & p. 8-14.
Essential Question: What evidence is
there that evolution has occurred?
Evidence of Evolution
1. Fossils- The remains of any past life
Types of fossils
(1) imprint
(2) mold
(3) cast
(4) petrified
(5) frozen
2. Radioactive
• Half-life Time it takes
for one half of
a given
quantity of a
radioisotope
to decay
dating
3. Comparative Anatomy
a. Homologous structures parts of the body that are
similar in structure show
evidence of common origin
b. Analogous structures – parts of the
body that are similar in function but
not structure – does not show common
origin.
Bird’s wing and bee’s wing are analogous structures
c. Vestigial structure – structures that
no longer function in the body – may
show relationship with other organisms,
indicate common origin.
Examples: appendix
or a whale’s pelvis
4. Comparative
Embryology
• Early vertebrate
embryos strongly
resemble one
another
• Same plan of
development
5. Comparative
Biochemistry
• The More similar
the DNA & protein
structure of 2
organisms, the
more closely they
are related.
Pointing to a
recent common
ancestor.
3/28/12--Take out Your “Evidence for Evolution”
Graphic Organizer
1. Contrast biogenesis & spontaneous generation.
Which is believed today?
2. Briefly describe the experiments of each of these
scientists.
a. Redi b. Spallanzani c. Pasteur d. Miller&Urey
3. ____ hypothesized that the gases of Earth’s
primitive atmosphere led to the formation of
organic molecules & living things.
4. What was early Earth like?
5. _____ proposes that eukaryotic cells arose from
communities of prokaryotic organisms.
• Read p. 416-422 & p. 382-386.
• Find & cut out pictures/letters to illustrate
the 5 pieces of evidence for evolution.
Model your paper after the diagram on the
board.
• On the back of your paper:
• –Answer questions #1 & 2 only on p. 422.
• –Answer question #3 on p. 386.
3/29/12- Take out your Evol.
Poster
Do-Now:On the back of your Evol. Poster:
• –Answer questions #1 & 2 only on p. 422.
• –Answer question #3 on p. 386.
Turn in Evol. Poster on top of overhead &
Complete the Evolution Vocab Word
Search.
Letters punched out: S, M
Words punched out: Endosymbiotic Theory
& Half-life
Two theories of Evolution
Jean Baptist Lamarck –
Theory of Acquired
Characteristics
Traits you develop you
pass on---ACQUIRED
TRAITS
How would
Lamarck explain
the long neck on
the giraffe?
Would her children have longer
necks?
Charles Darwin –
Theory of Natural
Selection
Survival of the fittest.
Fig. 17.5a, p. 274
Darwin
Wolf
Pinta
Marchena
Genovesa
Santiago
Bartolomé
Fernandia
Råbida
Pin zon
Seymour
Baltra
Santa Cruz
EQUATOR
Santa Fe
Tortuga
Isabela
San Cristobal
Española
Galåpagos
Islands
Floreana
Fig. 17.5b, p. 275
Darwin’s Finches
• Darwin saw many of the islands in the
Galapagos had their own species of finch.
• Each bird had a unique beak and well
adapted body for the type of food found in
its area.
• The birds were all similar, but were
different species.
• Darwin realized they must have evolved
from a common ancestor.
Fig. 17.7, p. 277
A few individuals of a
species on the mainland
reach isolated island 1.
Speciation follows genetic
divergence in a new habitat.
Later in time, a few
individuals of the new
species colonize nearby
island 2. In this new
habitat, speciation follows
genetic divergence.
Speciation may also
follow colonization of
islands 3 and 4. And it
may follow invasion of
island a by genetically
different descendants of
the ancestral species.
1
3
2
4
1
2
1
3
2
4
Fig. 19.11 p. 303
KONA
FINCH
extinct
KAUAI AKIALAOA
AMAKIHI
LAYSAN
FINCH
IIWI
AKIAPOLAAU
APAPANE
MAUI
PARROTBILL
fruit and seed eaters
insect and nectar eaters
FOUNDER SPECIES
Fig. 19.12 p. 303
Theory of Natural Selection
1. Overproduction- - populations increase at
a higher rate than their food supply and the
size of a population is limited by the availability
of food
Theory of Natural Selection
1. Overproduction
2. Struggle for Existence – results from
the competition between organisms for
available food, shelter and living space.
Theory of Natural Selection
1. Overproduction
2. Struggle for Existence
3. Variations – differences make every
individual different from every other
individual
Theory of Natural Selection
1. Overproduction
2. Struggle for Existence
3. Variations
4. Natural selection–- those members best
adapted will survive longer and reproduce
Theory of Natural Selection
1. Overproduction
2. Struggle for Existence
3. Variations
4. Natural selection
5. New Species – accumulated
variations in an isolated population will
eventually produce a new species =
Speciation
How Natural Selection Works
Example: The Peppered Moth
The peppered Moth,
Biston beularis, lives in
England. There are
two colors of this
moth.
Before the Industrial
Revolution the bark of
trees were light colored
because they were
covered with greygreen lichens.
If you were a bird
which moth would you
eat?
After the Industrial
Revolution the bark
of the trees were
dark because the
lichens were killed
by pollution.
Which moth is
visible now?
Other Examples of
Natural Selection
• Bacteria becoming resistant to antibiotics
• Insects becoming resistant to pesticides
Next…
• Read p. 369-381 quietly.
3/30/12Do Now: Be Ready to Pass up DONows;Study-Wk 12
1. ____ is known for his theory of acquired traits.
EXPLAIN the theory of acquired traits.
2. ____ is known for the theory of natural selection.
DESCRIBE what natural selection is.
3. ____ attempted to disprove spontaneous
generation by setting up an experiment with jars of
meat.
4. ____ attempted to disprove spontaneous
generation by setting up an experiment with flat
top flasks of broth.
5. ___ & ___ set up an experiment to test Oparin’s
hypothesis about the conditions of early earth.
3/29/12- Take out your Evol.
Poster
Do-Now:On the back of your Evol. Poster:
• –Answer questions #1 & 2 only on p. 422.
• –Answer question #3 on p. 386.
Turn in Evol. Poster on top of overhead &
Complete the Evolution Vocab Word
Search.
Letters punched out: S, M
Words punched out: Endosymbiotic Theory
& Half-life
Patterns of Evolution
• Macroevolution refers to large-scale
evolutionary patterns and processes that
occur over long periods of time.
Patterns of Evolution
Different patterns provide different paths to
explain the degree of variation among
organisms.
• Convergent
Divergent
Convergent Evolution – two different
species that did not come from a
common ancestor but are very similar in
appearance and life style
Example: sharks and dolphins
Divergent Evolution – two different species
that came from a common ancestor,
usually due to a different habitat.
Example: horse and donkey
Natural selection can affect the distributions
of phenotypes in any of three ways:
1. Directional Selection
• When individuals at one end of the
curve have higher fitness than
individuals in the middle or at the
other end, directional selection
takes place.
• The range of phenotypes shifts as
some individuals survive and
reproduce while others do not.
Natural Selection on
Polygenic Traits
• In this case, birds with larger beaks have higher
fitness. Therefore, the average beak size
increases.
2. Stabilizing Selection
• When individuals near the center of
the curve have higher fitness than
individuals at either end of the curve,
stabilizing selection takes place.
• This keeps the center of the curve at
its current position, but it narrows the
overall graph.
Human babies born at an average mass are
more likely to survive than babies born
either much smaller or much larger than
average.
3. Disruptive Selection
• When individuals at the upper and
lower ends of the curve have higher
fitness than individuals near the
middle, disruptive selection takes
place.
• If the pressure of natural selection is
strong enough and long enough, the
curve will split, creating two distinct
phenotypes.
If average-sized seeds become scarce, a bird
population will split into two groups: one that eats
small seeds and one that eats large seeds.
Next…
• Read p. 398-399 & complete the ch. 15
wkst (p. 185 & 187).
VOCAB QUIZ TOMORROW!
4/10/12-Be working when bell rings…
Do-Now:
• Take out yesterdays Evolution Crossword
from yesterday & Complete
• Study for Evolution Vocabulary Quiz
• Week 13 Vocab on left of Smart Bd
• No closed toed shoes…No Lab
Extra Credit: Friday—Hypnosis—7pm, Gym
***Evolution Test Quest*** Thursday
4/11/12-Get out “Evolution”Safari Video
Notes from Monday 4/9/12
Do-Now:
• On the back there is a word
puzzle/questions. Answer questions #2-6
BEFORE you search for the words.
• Set out your Evolution Review to be
checked.
Genes & Variation
• Many genes have
at least two forms,
or alleles.
• An individual
organism is
heterozygous for
many genes.
• Genetic variation is
studied in
populations.
• A population is a
group of individuals
of the same species
that interbreed.
• A gene pool
consists of all
genes, including all
the different alleles,
that are present in a
population.
• The relative frequency of an allele is
the number of times the allele occurs in
a gene pool, compared with the number
of times other alleles for the same gene
occur.
• Relative frequency is often expressed
as a percentage.
– In genetic terms, evolution is any
change in the relative frequency of
alleles in a population.
Variation and Gene Pools
Sample Population
• Gene
Pool for Fur Color inFrequency
Mice of Alleles
allele for
brown fur
allele for
black fur
• Sources of Genetic Variation
– The two main sources of genetic
variation are mutations and the genetic
shuffling that results from sexual
reproduction.
• A mutation is any change in a sequence of
DNA.
• Genetic Shuffling redistributes genes
A random change in allele frequency is
called Genetic Drift
• Genetic drift may occur when a small group of
individuals colonizes a new habitat.
• Individuals may carry alleles in different relative
frequencies than did the larger population from
which they came.
• The new population will be genetically different
from the parent population
• When allele frequencies change due to
migration of a small subgroup of a population it
is known as the Founder Effect.
Evolution Versus Genetic
Equilibrium
• The Hardy-Weinberg principle
states that allele frequencies in a
population will remain constant unless
one or more factors cause those
frequencies to change.
• When allele frequencies remain
constant it is called genetic
equilibrium.
Evolution Versus Genetic
Equilibrium
– Five conditions are required to maintain genetic
equilibrium from generation to generation:
1.There must be random mating,
2. The population must be very large,
3. There can be no movement into or out of
the population,
4. There can be no mutations, and
5. There can be no natural selection.
Speciation
• The formation of a new species
• A species is a group of organisms
that breed with one another
and produce fertile offspring.
Fossils and Ancient Life
• Fossils and Ancient Life
• Paleontologists are scientists who collect and
study fossils.
• A fossil is the remains of a once living thing
• All information about past life is called the fossil
record.
• The fossil record includes information about the
structure of organisms, what they ate, what ate
them, in what environment they lived, and the
order in which they lived.
– The fossil record provides evidence about the
history of life on Earth. It also shows how
different groups of organisms, including
species, have changed over time.
• The fossil record provides incomplete information
about the history of life.
• Over 99% of all species that have lived on Earth
have become extinct, which means that the
species has died out
How Fossils Form
• Fossils can be as large as a complete, preserved
animals, or as small as a fragment.
• Most fossils form in sedimentary rock.
• Sedimentary rock forms when exposure to the
elements breaks down existing rock into small
particles of sand, silt, and clay.
How Fossils Form
• Fossil Formation Water carries small rock
particles to lakes and
seas.
How Fossils Form
How Fossils Form
The preserved remains
may be later discovered
and studied.
Interpreting Fossil Evidence
• Paleontologists determine the age of fossils using
relative dating or radioactive dating.
• In relative dating, the age of a fossil is determined
by comparing its placement with that of fossils in
other layers of rock.
• Rock layers form in order by age—the oldest on
the bottom, with more recent layers on top.
• Relative dating allows paleontologists to
estimate a fossil's age compared with that of
other fossils.
Interpreting Fossil Evidence
• Index fossils are used to compare the relative
ages of fossils.
• An index fossil is a species that is recognizable
and that existed for a short period but had a wide
geographic range.
• Relative Dating
Interpreting Fossil Evidence
•Radioactive dating is the use of half-lives to determine
the age of a sample.
•A half-life is the length of time required for half of the
radioactive atoms in a sample to decay.
–In radioactive dating, scientists calculate the age of a
sample based on the amount of remaining radioactive
isotopes it contains.
•Carbon-14 begins to decay when an organism dies.
•Carbon-12 is not radioactive and does not decay.
•By comparing the amounts of carbon-14 and
carbon-12 in a fossil, researchers can determine
when the organism lived.
Interpreting Fossil Evidence
Reading Assignment
Read p. 416-422.
Book Work:
• P. 428 #4 only
• P. 440 # 1, 2, & 3 only
• You may write the questions and your
answers OR write the answers using
complete sentences.
• Evolution Quest Tomorrow….
4/12/12
Do-Now:
1. Contrast convergent & divergent evolution.
2. When individuals at one end of the curve have
higher fitness than individuals in the middle or
at the other end, ___ takes place.
3. If average-sized seeds become scarce, a bird
population will split into two groups: one that
eats small seeds and one that eats large
seeds. This is an example of ____.
Evolution Bio-Bingo!
1. Evolution
2. Adaptation
3. Disruptive
4. Embryology
5. Fossils
6. Analogous
7. Speciation
8. Vestigial
9. Darwin
10.Extinct
11.Natural Selection
12.Galapagos
13. Variation
14. Competition
15. Mutation
16. Homologous
17. Stabilizing
18. Lamarck
19. Redi
20. Spallanzani
21. Pasteur
22. Miller & Urey
23. Biogenesis
24. Endosymbiotic
10/31/11-Happy Halloween!
Pick up your books.
Do-Now:
1. Which is really happening: Genetic
Equilibrium or Evolution? Why?
2. Define speciation. What made Darwin
believe he observed speciation in the
Galapagos Islands?
3. The two main sources of genetic variation
are ___ & ____.
11/15/10-Pick up your book.
Do-Now:
1. List the four types of evidence that can be
used to support the theory of evolution.
2. Explain how each of your answers from
#1 could be used to support the theory of
evolution.
Evolution Test TOMORROW.
11/16/10-You do NOT need
your book today.
Do-Now:
1. The age of Earth is estimated to be ____.
2. The process by which a population
becomes better suited to its environment
is known as ____.
3. List two examples of vestigial structures.
4. The belief that life came to earth from
some other planet is called the ____.