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 generation-living 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

Mitochondrion

Aerobicbacteria

Nuclear envelopeevolving

Ancient Prokaryotes

Plants and plantlike protists

Primitive PhotosyntheticEukaryote

Primitive AerobicEukaryote

Ancient AnaerobicProkaryote

Chloroplast

Animals, fungi, and

non-plantlike protists

Photosynthetic bacteria

Origin of Eukaryotic Cells

Ancient Anaerobic Prokaryote

Nuclear envelopeevolving

Aerobicbacteria

Ancient Prokaryotes

Origin of Eukaryotic Cells• Prokaryotes that

use oxygen to generate energy-rich molecules of ATP evolved into mitochondria.

Mitochondrion

Primitive Aerobic Eukaryote

Origin of Eukaryotic Cells

Primitive Photosynthetic Eukaryote

Chloroplast

Photosynthetic bacteria

Prokaryotes that carried out photosynthesis evolved into chloroplasts.

Reading Assignment

• Read p. 423-428 & p. 8-14.

Essential Question: What evidence is there that evolution has occurred?

Evidence of Evolution

1. Fossils-Types of fossils

(1) imprint

The remains of any past life

(2) mold(3) cast(4) petrified(5) frozen

2. Radioactive dating• Half-life -

Time it takes for one half of a given quantity of a radioisotope to decay

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 Organizer1. 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. PosterDo-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, MWords 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?

Fig. 17.5a, p. 274

Charles Darwin – Theory of Natural Selection

Survival of the fittest.

Fig. 17.5b, p. 275

Isabela

Darwin

Wolf

Pinta

Marchena Genovesa

Fernandia

SantiagoBartolomé

RåbidaPin zon

SeymourBaltra

Santa Cruz

Santa FeTortuga

Española

San Cristobal

Floreana

EQUATOR

GalåpagosIslands

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

Fig. 19.11 p. 303

1

23

4

1

23

4

1

2

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.

Fig. 19.12 p. 303

FOUNDER SPECIES

insect and nectar eatersfruit and seed eaters

KAUAI AKIALAOA

AMAKIHI

IIWI

APAPANE

KONA FINCH extinct

LAYSAN FINCH

AKIAPOLAAU

MAUI PARROTBILL

Theory of Natural Selection1. 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 Selection1. Overproduction

2. Struggle for Existence – results from the competition between organisms for available food, shelter and living space.

Theory of Natural Selection1. Overproduction

2. Struggle for Existence3. Variations – differences make every individual different from every other individual

Theory of Natural Selection1. Overproduction

2. Struggle for Existence3. Variations

4. Natural selection–- those members best adapted will survive longer and reproduce

Theory of Natural Selection

1. Overproduction2. Struggle for Existence3. Variations4. Natural selection5. 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 grey-green 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.

3/30/12-Do Now: Be Ready to Pass up DONows;Study-Wk 121. ____ 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. PosterDo-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, MWords 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 EvolutionDifferent 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

Divergent Evolution – two different species that came from a common ancestor, usually due to a different habitat.

Example: sharks and dolphins

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 onPolygenic 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 LabExtra 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• Gene Pool for Fur Color in MiceSample Population Frequency of Alleles

allele forbrown fur

allele forblack 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 FormThe 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….

4/12/12Do-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. Evolution2. Adaptation3. Disruptive4. Embryology5. Fossils6. Analogous7. Speciation8. Vestigial9. Darwin10.Extinct11.Natural Selection12.Galapagos

13. Variation14. Competition15. Mutation16. Homologous17. Stabilizing18. Lamarck19. Redi20. Spallanzani21. Pasteur22. Miller & Urey23. Biogenesis24. 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 ____.