Bio Unit 6 - Evolution

5/3/16

• Entry Task

• How do scientific ideas evolve? In other words, how do they change over time?

• Discuss. • Then, when do you think earth was “born”?

When do you think life was “born”? Have they changed over time?

• Hand back tests: IF YOU GOT 60% or less COME TOMORROW MORNING FOR REFLECTIONS!

Today’s Agenda • Today we will consider geological and biological evolution with a

timeline.

1. Each team will get an envelope with events in earth’s history.

2. You will attempt to order these on a timeline.

3. To make your timeline: Measure 5 meters of PAPER TAPE. Cut and tape to the floor along the side, back or aisle of the classroom. USE MASKING TAPE!

4. Make a mark every 10 centimeters. Each whole meter is 1 billion years. Each 10 cm = 100,000,000 (100 million years)

5. Paperclip your events where you think they belong in earth’s history.

6. Look at other team’s proposed timelines. DISCUSS.

7. CONSIDER ANSWERS. Adjust your timeline correctly.

8. DISCUSS. Read a few items from poster at http://www.hhmi.org/biointeractive/earth-evolution-intersection-geology-and-biology

• FINISHED EARLY? Please clean your REEBOP parts and return to trays

5/3/16

• Exit Task

• What relationships might there be between geological changes over time and biological changes over time?

5/4/16

• Entry Task

• How have these 3 systems of earth: (atmosphere, solid earth and organisms) affected each other over earth’s history? List a few ways.

Today’s Agenda

• 5 min – divvy your paper strips, paperclip to timeline

• 5 min - Look at other team’s proposed timelines. DISCUSS.

• 5 min - CONSIDER ANSWERS. Adjust your timeline correctly.

• 5 min - DISCUSS. Read a few items from poster at http://www.hhmi.org/biointeractive/earth-evolution-intersection-geology-and-biology

• 20 min - NOTES

Genetic Variation – how does it increase?

• Read page 484 from your textbook (attached).

– Identify and explain the 2 sources of genetic variation.

• Sexual Reproduction – including meiosis/crossing over and fertilization

• Random mutations – gene mutations and chromosomal mutations

Meiosis • Meiosis: produces four UNIQUE sex cells for

reproduction • Each cell is HAPLOID – ½ the chromosomes of the

body cells • Crossing over may occur • Allows for differences (variation) in populations • Fertilization restores the chromosome number to

DIPLOID in offspring • Sexual Reproduction also increases genetic

variation

Comparing meiosis and mitosis MITOSIS

MEIOSIS

BODY CELLS SEX CELLS – sperm or eggs

What if there was a mutation here when DNA replicated?

What if there was a mutation here when DNA replicated?

Mutations Effect on Organism/Offspring

• Mutation in DNA of body cell – Effect on whole organism

• Localized to cells which reproduce from the mutated cell • Neutral, harmful, beneficial • Example: skin cancer from too much UV exposure - harmful

– Effect on offspring = ZERO

• Mutation in DNA of sex cell – Effect on whole organism = ZERO – Effect on offspring

• Neutral, harmful, beneficial • Example: sickle cell anemia - harmful • Example: bugs develop resistance to chemicals – beneficial

(for survival of bug!)

Mutations in sex cells can lead to new traits in offspring (increasing genetic

variation in a population)

Sexual Reproduction (½ the genetic material from mom and ½ from dad) also increases genetic variation

What kind of cell must this be? Reproductive Cell!

2 main kinds of mutations

Gene Mutations

• Point mutations occur at a single point in DNA sequence

– Substitutions for one base only changes 1 amino acid

– Insertions or deletions, also known as frameshift mutations, cause changes in many amino acids

• Occur 1x/10,000,000 bases of replicating DNA

Chromosomal Mutations

• Deletion – of a section of chromosome

• Duplication – extra copy of section of chromosome

• Inversion – reverses direction of a portion

• Translocation – part of one chromosome breaks off and attaches to another

What kind is it? How might this happen? How many amino acids does

it affect?

• Original DNA: AAG GCG ATA

• Mutation: AAG GGG ATA

• Original DNA: AAG GCG ATA

• Mutation: AAG GAC GAT A

• Original DNA: AAG GCG ATA

• Mutation: AAG GGA TAC (note a C was removed…)

Causes of Mutations

• Errors during DNA replication in mitosis or meiosis

• Mutagens – environmental factors can cause damage to DNA making mutations more likely.

• Example: Tobacco smoke or environmental pollutants or radiation (UV or X-rays)

• Mutations in DNA: can (not always) lead to unique traits, which may help or hinder survival!!

Organism Environment Unique Trait Bunny Rabbit Winter

Cactus Desert

Cheetah African Savanna

Chameleon Jungle

Peacock Mating Season

5/4/16

• Exit Task

• CANCELLED: What 2 things can increase genetic variation within a population?

5/5/16

• Entry Task

• Read page 484 from your textbook.

– Identify and explain the 3 sources of genetic variation

Today’s Agenda

• Finish notes on Increasing Genetic Variation: sexual reproduction and mutations

• Watch video from HHMI: Constant Changes, Common threads http://media.hhmi.org/hl/05Lect1.html

Rock Pocket Mouse

• Watch video -- take notes http://media.hhmi.org/hl/05Lect1.html

• Run simulation to see how coat color changes over generations of mice in a changing environment.

• REFLECT: How do random changes in organisms interact with a changing environment? What happens over many generations?

• Start Rock Pocket Mouse Packet • http://www.hhmi.org/biointeractive/activities/po

cketmouse/Mouse_ColorVariation_Student.pdf

5/5/16

• Exit Task

• What are the 2 categories of mutations?

• Which ones have the least affect? Most affect?

5/6/16

• Entry task

• Say Something Nice

Today’s Agenda

• Finish Video.

• REFLECT: How do random changes in organisms interact with a changing environment? What happens over many generations?

• Start Rock Pocket Mouse Packet

• http://www.hhmi.org/biointeractive/activities/pocketmouse/Mouse_ColorVariation_Student.pdf

5/6/16

• Exit Task

• Trade and Grade – turn in entry/exit task sheets

5/9/16

• Entry Task

• How do random changes in organisms interact with a changing environment? What happens over many generations?

• Use Rock Pocket mice and lava flows as an example.

Today’s Agenda – Rock Pocket Mice Lab • FOLLOW THE PROCEDURE ON HANDOUT: • Consider images 1-4. Each page shows 2 different locations at the

same moment in time. • In your comp books, record the number of light and dark mice

– Example: Image 1 – location A dark mice____light mice ____ – Location B dark mice____light mice ____

• Place the images in chronological order. Explain your thinking on handout.

• Answer #4 in your comp book based on the movie we watched Friday.

• Class discussion about order of images. Fill in data table on #5 on handout.

• Graph #6 on graph paper I give you. • Answer analysis questions in your comp books.

5/9/16

• Exit Task

• Explain why a rock pocket mouse’s fur-color influences its overall fitness (or the ability to survive and produce offspring) in a changing environment.

5/10/16

• Entry Task

• Compare and contrast meiosis and mitosis.

• Next, summarize the steps of protein synthesis and name the location of each process. What is the product?

Today’s Agenda

• Complete practice worksheets to study for tomorrow’s test.

• Get back your punnett ½ sheet from last test. Consider where you went wrong/right.

• Note: this test will mainly cover meiosis/mitosis comparisons; protein synthesis and a punnett square ½ sheet including a dihybrid cross.

5/10/16

• Exit Task

• What will you complete/study tonight?

• NOTE: There will be NO reflections offered on this test.

5/11/16

• Entry Task – none PREPARE FOR TEST: pencil.

• You may review answers from the answer key to the review sheet before the test.

• DO NOT WRITE ON TEST Packet! • Write on half sheet and pencil on scantron. • Stay quiet – no cheating! Plus there are different

versions of test.

Today’s agenda

• Test

• Extra time? Watch video: Fossils, Genes and Embryos by Dr Kingsley (HHMI) https://www.youtube.com/watch?v=ZhxJkGwS_9U

• Or on disc on my desk in “Evolution: constant change and common threads”

5/11/16

• Exit Task

• None - testing

5/12/16

• Entry Task

• What do you think provides evidence for evolution?

• Rock Pocket Mice Lab – discuss tomorrow.

Answers

• Students may bring up fossils, that dinosaurs are no longer alive, or that organisms resemble each other but are different.

• DNA is a universal molecule, which can be changed and inherited, and this provides part of the mechanism of evolution.

• Also, in a changing environment some organisms will have an advantage and survive and reproduce to pass on their genes while others die.

Today’s Agenda

• Finish video

• Watch video: Fossils, Genes and Embryos by Dr Kingsley (HHMI)

• On disc on my desk in “Evolution: constant change and common threads”

• Or on youtube https://www.youtube.com/watch?v=ZhxJkGwS_9U

5/12/16

• Exit Task

• Describe 4 pieces of evidence for evolution as described in the video lecture.

5/13/16

• Entry Task

• Say Something Nice

• Review Rock Pocket Mice Q/A

Today’s Agenda

• Finish retest if you needed more time on Wednesday.

• Finish Fossils, Genes and Embryos video.

• Notes on Evidence of Evolution

5/13/16

• Exit Task

• Trade and Grade Entry/Exit tasks

5/16/16

• Entry Task

• Consider this phylogeny carefully. Who is the oldest common ancestor?

• Who is most closely related to the Lutra lutra?

Today’s Agenda

• 13 select minutes of Fossils, Genes, Embryos

• Notes on Evolution

Evolution

• Evolution: change in organisms over time - the process by which modern organisms have descended from ancient organisms

All living things are related to a COMMON ANCESTOR!!!

What do phylogenetic trees show you? • Relationships among

species – those on a “fork” together are closest

• Time since a speciation event (splitting)

• The main branches are common ancestors

Evidence of Evolution

• Evidence:

1. Presence of Fossils found in rock layers

2. Homologous and Vestigial Structures

a. Homologous: Similar Structures

b. Vestigial: Unused structures; whale pelvis, human

wisdom teeth

Evidence of Evolution

Fossil Record Homologous Structures

Evidence of Evolution

3. DNA Comparisons

• Humans and mice are 99% similar in DNA, so they are

closely related

4. Embryos

• Not closely and closely related organisms have similar

embryos

Evidence of Evolution

DNA Comparisons

Embryos

Natural Selection • Natural Selection: “survival of the fittest,

failure of the worst” – Over-reproduction sets up a struggle for existence

– Natural selection selects for variations in the population (result of mutation & sexual reproduction) that are adaptive

– The “goal” of life is to

survive and reproduce

(pass adaptive genes to

next generation)

LS4.C: Adaptation

• Natural selection leads to adaptation – a population dominated by organisms that are

anatomically, behaviorally, and physiologically well suited to survive and reproduce in a specific environment.

– the differential survival and reproduction of organisms in a population that have an advantageous heritable trait leads to an increase in the proportion of individuals in future generations that have the trait and to a decrease in the proportion of individuals that do not.

• Adaptation also means that the distribution of traits in a population can change when conditions change.

5/16/16

• ExitTask

• Explain how in a changing environment, organisms with advantageous and heritable traits will increase in numbers over generations.

5/17/16

• Entry Task

• Watch: http://study.com/academy/lesson/cladograms-and-phylogenic-trees-evolution-classifiations.html#lesson

• Explain the difference between a cladogram and a phylogenetic tree.

Two videos…two quizzes today

• Crash Course on Natural Selection

• http://goo.gl/forms/zo07JsabCP

• Quiz

• Mr. Anderson's Lecture on Evidence of Evolution

• http://goo.gl/forms/MDW7eSeF6g

• Quiz

5/17/16

• Exit Task

• None – quizzing

5/18/16

• Entry Task