Objective : Understand How Homologous Structures Are an Evidence of Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation 1. Meiosis and fertilization are important processes because they may most immediately result in A) many body cells B) genetic variation C) natural selection D) 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 reproduction B) an increase in population size C) the production of similar organisms D) diversity among organisms DO NOW

Objective : Understand How Homologous Structures Are an Evidence of Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation Do Now: Compare and contrast the forelimbs of vertebrates below

SimilaritiesDifferences Same kinds of bones: humerus, radious, ulna, carpal, and fingers Same structure: pattern Different bone shapes and sizes Different limb’s functions: swim, fly, crawl, grab, run Objective : Understand How Homologous Structures Are an Evidence of Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

FrogLizardBatHuman CatWhaleBird 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 airGrabbing things Swimming in water Running & jumping On ground Flying in air Crawling on ground Objective : Understand How Homologous Structures Are an Evidence of Evolution Key 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 Evolution Key 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 Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation Homologous structures: Same structureDifferent function Adapted to a different environment Share a close common 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 Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

SimilaritiesDifferences 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 Evolution Key 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 Evolution Key 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 Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation

Objective : Understand How Homologous Structures Are an Evidence of Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation Analogous structures: Different structureSame 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 Evolution Key Words: evidence, forelimbs, homologous, analogous, ancestor, adaptation