Natural Selection and Evidence to Support Evolution ACADEMIC ninth grade science

Natural Selection Darwin’s Mechanism for Evolution Overproduction Inherited variation Struggle to survive Successful reproduction Adaptation of the species

Overproduction Too many offspring produced Many variations -Gene Pool: the total of all alleles (variations) in population -What is the allele frequency for feather color for this gene pool?

2. Inherited Variation Mutation and random mating make variations -Mutation: Changes in DNA ****(Darwin was missing this) -Random mating: mixing genes in reproduction Most birds are blue Sometimes, one is born green Sometimes, one is born blueish-green

3. Struggle to Survive Organisms compete for resources (food, shelter, mates, etc.) Those with better variations survive

The birds face the challenge of blending in to survive.

Only some will survive and have the opportunity to pass on their successful genes. Ugh!, so full… EEP! Blue-green birds stand out more Blue-green birds are eaten

4. Successful Reproduction Successful traits are passed to offspring -More organisms with the successful trait -Fewer organisms with the less successful trait(s) How has the allele frequency changed in this population? This is evolution!

5. Adaptation of the Species Adaptation: process by which a species becomes better suited to its environment ? Hee, hee…

Warm up… 1. Use the diagram and explain the process of natural selection.

Pace of Evolution GRADUALISM: Slow Even pace PUNCTUATED EQUILIBRIUM: Quick bursts Many periods of no change

WoolyBooger…

Warm up… Read the article on your sheet and begin to answer the questions on the back.

How does the WoolyBooger show NATURAL SELECTION?

Examples: Sickle cell Anemia Peppered Moth

Evidence to Support Evolution

1. Fossils Any trace of a dead organism Calcium in bones is replaced with harder elements Soft tissues don’t often fossilize Age determined by radiometric dating

Fossil Activity

Warm up… A Make FOUR observations (facts) about these fossil footprints. Consider size, shape, & position. Make FOUR inferences (educated guesses) about the prints that reconstruct the events that may have caused this pattern. There is more than one possible answer. B C

2. Comparative Embryology Vertebrates have similar early stages; gill slits, “fins”, a tail Differences accumulate as development continues New development instructions are added to old instructions inherited from ancestors.

2. Comparative Embryology

3. Transitional Forms Intermediates between old and new species Ex: modern horse descended from dog-sized animal with multiple toes

Transitional Forms Fish to Amphibians

Transitional Forms Reptiles to Birds

Transitional Forms Land Mammals to Aquatic Mammals

Transitional Forms Activity Turn to pages 112-113 in the GREEN textbook. Read about the transitional forms of the whale. In your notes, describe what scientists think the ancient ancestor the modern whale was like.

NOW… Watch the Sickle Cell Anemia Video Read the Sickle Cell Anemia Article Use the information to complete the FRONT of the Natural Selection Examples sheet

Warm up… Watch the Peppered Moth video Complete the BACK of the Natural Selection Examples sheet you received yesterday (We will do antibiotic resistance in another class period)

4. Homologous Structures Structures with a common ancestry Modified versions of structures from other organisms Ex: bones in appendages

4. Homologous Structures

5. Vestigial Structures Structures with no present function Remnants of the past; Previously served a function Ex: human appendix-may once have been used for digestion Ex: whale’s pelvis-not needed for swimming, is needed for walking

5. Vestigial Structures

Warm up… Take out the sheet from Friday Complete the chart and questions with your partner, using the packet on the table

Which is NOT homologous & Why? A Human Lizard Octopus B Bird Whale Grasshopper Lizard Human

6. DNA and Proteins DNA make an organism’s proteins DNA sequence holds the evolutionary history If species changes, their DNA changes Closely related organisms share more similar DNA Ex: humans and chimps share 98% DNA

6. DNA and Proteins Human-Human=99.5% similar Human-Chimpanzee=98% similar Human-Cat=90% similar Human-Cow=80% similar Human-Mouse=75% similar (90% analogous regions) Human-Chicken=60% similar Human-Fruit Fly=60% similar

DNA and Proteins Activity Cytochrome C article???????

So…evolution can cause speciation Speciation: formation of a new species as a result of natural selection

Madagascar & Speciation

Now… Read about Antibiotic Resistant Bacteria. Answer the questions on the back of the Natural Selection Examples Sheet

Warm up… 1. Use the diagram and explain the process of speciation.

Antibiotic Resistance

Now… Find your new group Complete Speciation Work time

Warm up… Did any individual Peppered moth change its color during its lifetime? Why? (or why not?) Explain the change from light colored to dark colored moths. 36:15

Now… Quick Check-15 minutes-you know it or you don’t Peppered Moth Graph This MUST be finished TODAY Graded TODAY and returned for the questions TOMORROW Work time

Warm up… What is the difference between an independent variable and a dependent variable? Explain the steps of Natural Selection. How does antibiotic resistance show natural selection?

Check yours… X Transitional Vestigial DNA Fossils Embryology Homologous Transitional Vestigial Embryology DNA Fossils Gill Slits… X Forelimbs… DNA… Archaeopteryx… Whale pelvis… Common ancestor… Modern horse…

Check yours… 2. UNDERLINE each of these terms or ideas (not the descriptions) Overproduction Inherited variation Struggle to survive Successful reproduction Adaptation of the species

Check yours… 3. CIRCLE your example Underline each piece of natural selection you used to defend it