HAPPY TUESDAY Bellwork for yesterday write video Today you will need: Something to write with, a new Bellwork Sheet and your Journal Turn in your homework.

HAPPY TUESDAY

Bellwork for yesterday write “video”

Today you will need: Something to write with, a new Bellwork Sheet and your Journal

Turn in your homework from yesterday (video worksheet)

Bellwork for today: 1.With a partner, discuss the white card on your table. 2. Then sort through the pink cards and choose the one

that you think would happen next.3. On your bellwork sheet EXPLAIN why you and your

partner chose that card. Use at least three sentences.

Standard: (7E)Analyze and evaluate relationship of natural

selection to adaptation.

Essential Question:What is evolution and what causes

it to happen?

What is Evolution?

Evolution: change in the traits of a population over time

Evolution is called “the grand unifying theory of biology.”Evolutionary theory continues to change as new data are

gathered and new ways of thinking arise.

Gene pool: the total number of genes of every individual in an interbreeding population.

Evolution can also be defined as a change in the gene pool over time.

Evolution can also be defined as a change in the gene pool over time.

What important contribution did Charles Darwin make to biology?

Charles Darwin: contributed more to our understanding of evolution than anyone else.

• Darwin traveled, made observations and collected evidence

b. Darwin published the results of his work in a book called On the Origin of Species.

Mechanisms of Evolution(How does evolution happen?)

There are 5 factors that can affect the frequency of a gene in the gene pool.

1. Genetic Mutation2. Non-random mating3. Natural Selection4. Small Population5. Gene Flow

1. Genetic Mutation:• DNA errors in replication, transcription, translation,

or because of environmental factors.– The source of all new genes/traits in a population

• If mutations are passed on to offspring (over generations), then evolution has occurred

2. Non-Random Mating• Not all mates are created

equal.

•In many species, mates are not selected at random. They are chosen for specific characteristics..

•This limits the size of the gene pool because only the genes of the mating individuals are passed to the next generation.

3. Natural selection: the process by which individuals with characteristics that are not well suited to their environment either die or leave few offspring.

It is not seen directly, but only observed as changes in a population over a long time.

3. Natural Selection• survival of the fittest• advantageous genes are passed

on to the next generation while harmful genes are eliminated

*the driving force of evolution

Examples of natural selection

Why does natural selection happen?

1. Population size is limited by

environmental resources

2. Fitness: the ability of an organism to survive and reproduce.

Adaptation: any inherited characteristic that increases an organism’s chance of survival.

Successful adaptations: - enable organisms to become better suited to

their environment - increase an individual’s ability to survive and

reproduce.

Humans have thousands of adaptations: large brain, opposable thumbs, excellent sensory organs, light, strong skeleton, etc.

Bunny Simulation

If only one species is considered the "fittest", why do we still have so many variations among species. Why do some birds have very long pointy beaks, while other birds have short flat beaks?

Debrief Options

• Create a chart on the bunny simulation• What are adaptations that can help the wolf

survive?• Quickwrite answering Essential Question.

Summary of Darwin’s Theory: Individual organisms differ and some of these variations are

heritable (passed on) Organisms produce more offspring than can survive and

many that do survive do not reproduce Because more organisms are produce than can survive, they

must compete for limited resources (food, shelter, etc) Each unique organism has different advantages (good) and

disadvantages (bad) Individuals best suited to their environment survive and

reproduce successfully These organisms that survive pass their heritable traits to

their offspring

Summary of Darwin’s Theory cont’d: Other individuals that are not suited for their

environment die or leave few offspring This process called natural selection causes species

to change over time Species alive today are descended with modification

from ancestral species (their ancestors) This process by which diverse species evolved from

a common ancestor unites all organisms on Earth into a single tree of life

What to do:1. Check you grade in the

back.2. Figure out which of the

assignments you need to make up.

3. Get the assignment.4. When finished, turn it in to

you class period tray.

IF YOU HAVE NOTHING TO MAKE UP:• Congratulations! You won a trip to

space! You are going to Mars to study the organisms that live there. When you arrive you observe 2 new species. Using the basic characteristics of Mars, create the two species you encounter with adaptations that are appropriate for life on Mars. Write 5 sentences describing the organisms and draw a picture of them on Mars.Basic Characteristics of Mars:

• Diverse terrain, including: mountains, valleys, polar ice caps, deserts• Atmosphere has clouds, thus rain• The red color is due to blowing sand• Has vegatation• It is VERY cold.