WARM UP- Please get a white sheet from the tray on my stool- there is space for your warm up!

IN YOUR OWN WORDS…

1.WHAT DOES ADAPTATION MEAN?

2.WHAT IS NATURAL SELECTION?

Evolution

S7L5. Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring.

a. Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwin’s finches and peppered moths of Manchester).

What’s the Standard?

Charles Darwin: Who is this guy?

Video Clip

Similarities and DifferencesCheckpoint: How did

Darwin think plants and animals had originally come to the Galapagos Islands?

Answer: Perhaps they had been blown out to sea or set adrift on a fallen log.

Adaptations

What is an Adaptation? An adaptation is a trait that helps an organism adjust to its environment, survive and reproduce.

Adaptation: Elephant

(Video Clip)

Adaptation: GiraffeCheckpoint: What type of adaptations allows giraffes to feed on a diet

of leaves from treetops? (LEMARC– BEFORE DARWIN)

Answer:

The body structure of the giraffe has adapted over time.

Evolution

What is Evolution? Darwin believed that species changed over time becoming better adapted to their environment. This process is slow and takes many generations.

Evolution

What makes an idea a Theory? It is well tested and explains many observations.

How does a Theory different from a fact? A fact is a specific observation, known to be true; a Theory is a broad concept, thought to be true because it explains many facts.

Natural SelectionNatural Selection

What is Natural Selection? Natural selection is the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.

Survival of the fittest! Who's Going to Survive?

Natural SelectionNatural Selection

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Natural SelectionNatural Selection

There are several factors that Darwin identified that affect the process of natural selection:

• Overproduction of offspring

• Competition

• Variations

Overproduction

Natural Selection

Competition Variation

OverproductionMost species produce

far more offspring than can possibly survive.

CompetitionCompetition is the

struggle between organisms for the limited resources in a habitat.

Variation

Variation is any difference between individuals of the same species.

Natural Selection: Examples

Are these two butterflies the same species?These are the Monarch and Viceroy butterflies.

The Monarch on the left is poisonous and the Viceroy is not.

Question: Why would it be beneficial for the Viceroy to look like the Monarch?

Natural Selection: Examples

Checkpoint: A species of hare (rabbit) that is found in a cold tundra environment. How are oversized feet an advantage to the Arctic Hare?

Natural Selection: Examples

How many moths do you see?How many moths do you see?

Warbler finch

Woodpecker finch

Small insectivorous

tree finchLarge

insectivoroustree finch

Vegetariantree finch

Cactus finch

Sharp-beaked finch

Small groundfinch

Mediumground finch

Large groundfinch

Insect eaters

Bud eater

Seed eaters

Cactuseater

Warbler

finch

Tree

finch

esG

round finches

variationnatural selection for best survival & reproduction

From 1 species to 14 species…

How Do New Species Form?

A new species might form when a group of individuals remains separated from the rest of its species long enough to evolve different traits.

How Do New Species Form?

How Do New Species Form?

Have the Have the Kaibab Kaibab Squirrel and Squirrel and the Abert the Abert Squirrel been Squirrel been isolated long isolated long enough to enough to become a become a new species?new species?

An example of Evolution through Gene Flow

An example of Evolution through Genetic Drift