Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

1. Meiosis and fertilization are important processes because they may most immediately result in

A) many body cellsB) genetic variationC) natural selectionD) immune responses

2. Exposure to cosmic rays, x-rays, ultraviolet rays, and radiation from radioactive substances may promote

A) a change from sexual to asexual reproductionB) an increase in population sizeC) the production of similar organismsD) diversity among organisms

DO NOW

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Do Now: Compare and contrast the forelimbs of vertebrates below

Similarities Differences

Same kinds of bones: humerus, radious, ulna, carpal, and fingers

Same structure: 1 + 2 + 5 pattern

Different bone shapes and sizes

Different limb’s functions: swim, fly, crawl, grab, run

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Frog Lizard Bat Human

Cat Whale Bird

Describe how each forelimb is suited for the environment and habitat of the animal it belongs to

Jumping and swimming in a pond Flying in air Grabbing things

Swimming in waterRunning & jumpingOn ground

Flying in air

Crawling on ground

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Limbs have different sizes, shapes, and functions because they are adapted to different environments

Limbs have the same pattern or structure because animals share a close common ancestor.

d. How do you explain the differences among these limbs in vertebrates?Why are they different?

b. How do you explain the similarities among these limbs in vertebrates? Why are they similar?

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

a. Are the forelimbs of these vertebrates made up of the same kinds of bones?

c. Do the forelimbs of these vertebrates perform the same function?

Yes

No

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Homologous structures:

Same structure Different function

Adapted to a different environment

Share a closecommon ancestor

How are the forelimbs of these animals similar and different in structure and function?

Are all these winged animals related?

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Similarities Differences

All of them have the same function: flying; and are adapted to the same environment, air.

Their wings have different structures: bones and muscles, feather, skin, scales, and membranes.

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

7. Compare the structures of pterodactyl wing, butterfly wing, bat wing, and bird wing show below. Identify and note similarities as well as differences.

Because all wings are adapted to the same environment (air) to carry out the same function (flying).

b. Each of these creatures has developed structures for flying (wing). Why do you think these different species have developed this similar adaptation?

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

a. Are all wings alike?

No

All winged creatures are NOT closely related because wings do not have the same structure. Therefore, winged creatures do not share an early common ancestor

No, because these wings have developed from different ancestors.

c. How do you explain the differences among these limbs in vertebrates? Why are they different?

d. Are all winged creatures related? Explain.

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Analogous structures:

Different structure Same function

Adapted to same environment

Do not share a close ancestor

DO NOW:• Explain what are homologous structures and analogous structures.• How are homologous structures an evidence of evolution?

Objective: Understand How Homologous Structures Are an Evidence of EvolutionKey Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation