Warm-up / EOC Prep- only write # 1 1. The process of DNA replication is necessary before a cell — A.makes a protein B. codes for RNA molecules C. divides.

Warm-up / EOC Prep- only write # 11. The process of DNA replication is necessary before a cell —

A.makes a protein B. codes for RNA molecules

C. divides into two cells D. modifies lysosome enzymes

2. In order to form recombinant DNA, scientists have found a way to cut a DNA segment using an enzyme named EcoRI. This enzyme cuts

DNA wherever the sequence

C-T-T-A-A-G occurs between the A

and the G base. Which of these

would result if EcoRI were used on

the DNA in the diagram to the right?

Agenda

• Warm-up

• Notes

• Darwin & Natural Selection Worksheet

• Natural Selection Fish Lab

• Whiteboards

• Clean-up

• Cool-down

Evolution is the core theme of biology

“Nothing in biology makes sense except in the light of evolution”

Theodosius Dobzhansky

Evolution Day 1

Darwin and the Theory of Evolution

Historical Background to

Darwin's Theory of Evolution

• The theory of evolution has developed through a lot of scientific observation and experimentation and most scientists today accept that evolution is the basis for the diversity of life on Earth.

• Charles Darwin, who later on developed the idea of natural selection, was born in England in 1809. He struggled in school and his father wanted him to be a doctor or a minister.

•In 1831 Charles Darwin left on a 5 year voyage on board the HMS Beagle to survey the coast of South America.

•He stopped off in the Galapagos Islands where the diversity of tortoises and birds amazed him

•In 1836 he returned to England

• He specifically studied finches, a type of bird with different sized beaks on the islands. Each type of beak was special for eating a different type of food. The birds adapted or changed so they could eat their food. One bird could have a long beak to get in holes to eat insects, and another might have a big beak to crush nuts.

Galapagos Islands

Darwin’s Finches

Darwin saw variation (difference) within species on the different Islands, but didn’t fully understand what he saw till he returned to England

• Another scientist, Jean Baptiste Lamarck, believed that physical features increased in size because of use or decreased in size because of disuse. His theories suggested that the organism’s life determined what traits got passed onto offspring.

• Giraffes

• No Evidence Ex: mice tails

• If a mouse has its tail cut-off, the mouse will not have tailless offspring

• A heavy influence on Darwin’s theories was the book Principles of Geology by Charles Lyell, which explained that the surface of the Earth changed slowly over many years.

• Another influence was the work of Thomas Malthus, who wrote that human populations can increase faster than the food supply.

•Geologists Hutton and Lyell explained that the Earth was old, and the economist Thomas Malthus explained population growth

• Populations breed rapidly, but populations don’t grow uncheckedMost organisms in a population die without breeding

• In 1859 Darwin published his book, On the Origin of Species

• Darwin did not want to be criticized for his ideas. However, he did not want to lose credit for his ideas either, so when a competing scientist, Alfred Russel Wallace was about to come out with a very similar idea Darwin had his ideas along with Wallace’s presented at a scientific meeting.

EVOLUTIONthe process by which modern

organisms have descended from

ancient organisms.

EVOLUTIONthe change over

time (in a gene pool or set of genes)

FITNESSthe physical traits and behaviors that enable organisms to survive

and reproduce in their environment

COMMON DESCENT

all species have common ancestors

ADAPTATIONprocess that enables organisms to become better suited to their

environments

HOW DOES ADAPTATION

WORK???Over time?

In a single generation?

ADAPTATION•TAKE PLACE OVER LONG PERIODS OF TIME!!!

•Only surviving (well adapted) organisms pass on their traits.

• The process by which new species form is called speciation. Geographic isolation plays a large role in speciation. Each environment is different with different pressures and challenges.

• Organisms adapt and change in response to their specific environment. If these populations become different enough they may even form separate species-which cannot interbreed.

REVIEW

• Who came up with the theory of natural selection?

• Charles Darwin

• What was the name of his ship?

• HMS Beagle

• What islands did Darwin visit?

• Galapagos

• Change over time is called…

• Evolution

• What types of birds did he study and what was different about them?

• Finches-their beaks

• All species have a common ancestor is known as …

• Common descent

• Species: group of genetically similar organisms that can interbreed, and produce FERTILE offspring.

• Population: group of organisms of the same species living in the same place at the same time.

• Adaptation: changing of a given species to become better suited to its environment

• Natural selection: is process by which populations change in response to their environment

• Adaptation occurs as a result of adaptation

• Complete the Darwin & Natural Selection worksheet.

• Remember, if it’s FALSE, make it TRUE!

Natural Selection Fish Lab• RULE # 1- DO NOT EAT THE FISH UNTIL MS.

GORNEY TELLS YOU TO!

• Each table needs– One bag of fish– One ocean (a paper plate)

– BE NEAT WITH THE FISH! DO NOT DROP THEM ON THE FLOOR! Pick them up if you do.

• Listen up, this will be graded!

Remember- hunt, Remember- hunt, mate, and then mate, and then

countcount

Clean-up

• Dispose of the fish “properly.” Do not leave ANY on the floor.

• Throw away the paper plates and bags.

• TURN YOUR FISH LAB PAPER WITH THE QUESTIONS ANSWERED INTO YOUR PERIOD’STRAY!

• Clean up this room!!

• That means…• No paper or trash on the floor• Chairs tucked under the desks• Desks straight

• THANK YOU!!

Warm-Up / EOC Prep1. Natural selection states that individuals

A with adaptive traits are more likely to surviveB on the bottom level of a hierarchy have the greatest reproductive successC demonstrating altruistic behavior are the ones with the most mutationsD remain unchanged over a period of time

2. Which of the following best defines common descent?   A All organisms came from the same ancestor. B All organisms have certain traits in common.

C All organisms descended from organisms that have traits in common with them.

D All organisms have similar body parts and organs in common.

Agenda

• Warm-Up

• Notes

• Evidence of Evolution Worksheet

• Evolution Vocabulary Table

• Whiteboards

• Clean-up

• Cool-Down

Evolution-Day 3

Age of the Earth and Evidence for Evolution

Organic Soup Theory

• No oxygen in the air• Organic molecules accumulated• A spark of lightning created

amino acids which over time produced organisms

What was the first life like?

• Anaerobic organisms…why?

• Single celled prokaryotes

• Asexual Reproduction

• Heterotrophs…why?

What came next?• Autotrophs…why?

• Probably used H2S instead of H2O…why?

• Then they made the switch to H2O…what happened?

• Sexual Reproduction--how would this influence evolution?

THE AGE OF THE EARTH

How did scientists figure out how old

the earth is?

2 ways to date the earth:

•Relative Dating—lower levels of rock are older than higher levels (not exact)

•Absolute Dating—the actual age of a sample using radiometric dating

RELATIVE DATING

RADIOMETRIC DATING

RADIOMETRIC DATING

RADIOMETRIC DATING

If you start with 1000 atoms of Uranium 238, how much will be left after 4.5 billion years? 500 atoms of U 238

RADIOMETRIC DATING

If you start with 1000 atoms of Uranium 238, how much will be left after 18 billion years? 62.5 atoms of U 238

According to scientists, the earth is about

4.5 billion years old.

THE FOSSIL

RECORD

Where do we get fossils from?

How do they form?

PLACES TO FIND FOSSILS:

• Ice• Tar Pits / quicksand / bogs• Amber / Sap• Sedimentary Rock—sediments fall on the living material and turn it to rock

Fossils in Amber

Are fossils a perfect record of

evolution? Why or why not?

No…but they are a

convincing window to the

past

Fossils are an incomplete record of evolution because:

• Fossil record is incomplete. Some organisms leave fossils, but most do not

• Quality is variable. Some are perfect, some are not…missing details

FOSSIL RECORDrepresents the preserved collective history of the

earth’s organisms.

The fossil record shows that changes in

organisms followed changes on earth.

Example:Shark teeth in Arizona

EVIDENCE FOR

EVOLUTION FROM LIVING ORGANISMS

Present-Day Evidence Present-Day Evidence for Evolutionfor Evolution

1. DNA1. DNA Similarity Similarity2. Biogeography2. Biogeography3. Homologous3. Homologous Structures Structures4. Vestigial Structures4. Vestigial Structures5. 5. EmbryosEmbryos

DNA Similarity

Evidence for Evolution

Species Percent DNA Binding

Human 100

Chimpanzee 98

Gibbon 94

Rhesus monkey 88

Tarsier 65

Lemur 47

Mouse 21

Chicken 10

DNA Comparisons between Humans and other Species

BiogeographyEvidence for Evolution

The study of patterns of geographical distribution

of plants and animals across Earth, and the

changes in those distributions over time

BIOGEOGRAPHY

Should species on these islands look the same?

Placental Animals and their Marsupial Counterparts

Placental Marsupial

Wolf Tasmanian Wolf

Flying Squirrel Flying Phalanger

Mouse Marsupial Mouse

Mole Marsupial Mole

Anteater Numbat

Bob Cat Tasmanian Tiger Cat

Lemur Spotted Cuscus

Biogeography suggests that

species evolved to fit their

environments

Homologous StructuresEvidence for Evolution

HOMOLOGOUS STRUCTURES

parts in different organisms that develop

from the same anscestral body part

HOMOLOGOUS STRUCTURES

Vestigial StructuresEvidence for Evolution

VESTIGIAL STRUCTURES

structures that have little or no purpose in the

present, but did in the past

Examples of Vestigial

Structures• Human appendix

• Tonsils

• Small vertebrae in humans

• Leg bones in snakes

EMBRYOSEvidence for Evolution

EMBRYOorganisms in the early stages of development.

EMBRYOS• Similar body structures / parts / organs

• Similar embryonic development

Embryo Similarity• What do you

notice about the first row?

• What happens as you move down each column?

• Clean up this room!!

• That means…• No paper or trash on the floor• Chairs tucked under the desks• Desks straight

• THANK YOU!!

Warm-Up / EOC Prep1. When Charles Darwin went to the Galapagos Islands he saw

various species of finches with different size beaks. The finches got their different beaks as a result of… 

A passing on acquired characteristicsB adapting to different types of food in the separate environmentsC adapting to different types of weatherD wanting different beaks2. In order for an organism to be biologically fit, it must:  A Survive B Survive and Reproduce C Be stronger than its competitors D Be in the right spot at the right time

Agenda

• Warm-Up

• Notes

• Evolution Flip-flop

• BIO BINGO

• Clean-up

Evolution Day 2

Natural Selection and Evolution of Populations

EVOLUTION BY NATURAL SELECTION

• Inherited variation exists within the genes of every population or species. This variation is the result of random mutations and sexual reproduction.

• Variations provides the material for natural selection

• In a particular environment, some individuals of a population or species are better suited to survive (survival of the fittest)-as a result of their variation-and they can then have more offspring

• These traits that help certain individuals survive and reproduce to spread in a population over time, and therefore a change in the entire population is seen-evolution occurs

• Each species has evolved and gathered adaptations in response to its particular environment.

• Certain forms of a trait become more common in a population because more individuals in the population carry the alleles for these forms.

• Natural selection causes the frequency of certain alleles in a population to increase or decrease over time, depending on if they are good (favorable) for survival or bad (not favorable for survival).

• If the trait is bad and does not help them survive, the trait will become less common (organisms will die, produce less offspring, and therefore not pass on the genes for the trait).

• What makes a successful variation or trait? One that makes it more likely for you to:

• Get food Not get eaten• Have children• Thermal conservation

NATURAL SELECTION

The process in nature where the most fit

organisms produce more offspring

Darwin’s Theory of Natural Selection

• The process of natural selection is driven by four important points that are true for all real populations:

1. All populations have genetic variation

2. The environment presents challenges to successful reproduction (If you don’t survive, you don’t pass on your genes to the next generation)

Darwin’s Theory of Natural Selection

3. Individuals tend to produce more offspring than the environment can support-which results in competition

• 4. Individuals that are better suited to their environment and can cope with the challenges presented by their environment tend to leave more offspring than those individuals that are less suited to the environment

• Given time, natural selection will produce different groups of organisms (speciation)

Example:

Giraffes show variation in the length of their necks.

Giraffes with longer necks get better food, have more babies(greater fitness)

Longer necks give birth to longer necks(trait is passed on in genes)

Results:

Over time, average neck length increases

Under other conditions, over longer periods of time, new species form(e.g. the Okapi)

REVIEW

• The process in nature where the most fit organisms produce more offspring is called…

• Natural selection

• What makes a successful variation?

• Helps not get eaten, have babies, thermal conservation, get food