Evidence of Change Guide - Continuing Strong Foundations …secondary.mysdhc.org/science/documents/FCIMS/Life/L… · · 2009-07-31Our videos and accompanying materials focus on

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Editors:Brian A. Jerome, Ph.D.Stephanie Zak Jerome

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Graphics:Dean Ladago

Fred Thodal

Teacher’s GuideMiddle School

Evidence of Change

2Visual Learning Company 1-800-453-8481 www.visuallearningco.com

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Evidence of Change

Visual Learning Company1-800-453-8481www.visuallearningco.com


Use and Copyright

The purchase of this video program entitles the user the right to reproduce or duplicate, in whole or in part, this teacher’s guide and the blackline master handouts for the purpose of teaching in conjunction with this video, Evidence of Change. The right is restricted only for use with this video program. Any reproduction or duplication, in whole or in part, of this guide and student masters for any purpose other than for use with this video program is prohibited.

The video and this teacher’s guide are the exclusive property of the copyright holder. Copying, transmitting or reproducing in any form, or by any means, without prior written permission from the copyright holder is prohibited (Title 17, U.S. Code Sections 501 and 506).

Copyright © 2006

ISBN 1-59234-122-5


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3Visual Learning Company1-800-453-8481www.visuallearningco.com

Table of ContentsPage

A Message From Our Company

National Standards Correlations

Student Learning Objectives

Assessment

Introducing the Video

Video Viewing Suggestions

Video Script

Student Assessments and Activities

Answers to Student Assessments

Answers to Student Activities

Assessment and Student Activity Masters

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Viewing Clearances

The video and accompanying teacher’s guide are for instructional use only. In showing these programs, no admission charges are to be incurred. The programs are to be utilized in face-to-face classroom instructional settings, library settings, or similar instructional settings.

Duplication rights are available, but must be negotiated with the Visual Learning Company.

Television, cable or satellite rights are also available, but must be negotiated with the Visual Learning Company.

Closed circuit rights are available, and are defi ned as the use of the program beyond a single classroom but within a single campus. Institutions wishing to utilize the program in multiple campuses must purchase the multiple campus version of the program, available at a slightly higher fee.

Discounts may be granted to institutions interested in purchasing programs in large quantities. These discounts may be negotiated with the Visual Learning Company.


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A Message from our Company. . .Dear Educator:

Thank you for your interest in the educational videos produced by the Visual Learning Company. We are a Vermont-based, family owned and operated business specializing in the production of quality educational science videos and materials.

We have a long family tradition of education. Our grandmothers graduated from normal school in the 1920’s to become teachers. Brian’s mother was an elementary teacher and guidance counselor, and his father was a high school teacher and superintendent. This family tradition inspired Brian to become a science teacher, and to earn a Ph.D. in education, and led Stephanie to work on science educational programs at NASA.

In developing this video, accompanying teacher’s guide, and student activities, our goal is to provide educators with the highest quality materials, thus enabling students to be successful. In this era of more demanding standards and assessment requirements, supplementary materials need to be curricular and standards based - this is what we do!

Our videos and accompanying materials focus on the key concepts and vocabulary required by national and state standards and goals. It is our mission to help students meet these goals and standards, while experiencing the joy and thrill of science.

Sincerely,

Brian and Stephanie Jerome


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National Standards CorrelationsNational Science Education Standards (Content Standards: 5-8, National Academy of Sciences, c. 1996)

Benchmarks for Science Literacy (Project 2061 – AAAS, c. 1993)

Life Science - Content Standard CDiversity and Adaptations of OrganismsAs a result of their activities in grades 5-8, all students should develop an understanding that:• Biological evolution accounts for the diversity of species developed through gradual processes over many generations. Species acquire many of their unique characteristics through biological adaptation, which involves the selection of naturally occurring variations in populations. Biological adaptations include changes in structures, behaviors, or physiology that enhance survival and reproductive success in a particular environment.

• Millions of species of animals, plants, and microorganisms are alive today. Although different species might look dissimilar, the unity among organisms becomes apparent from an analysis of internal structures, the similarity of their chemical processes, and the evidence of common ancestry.

The Living Environment - Evolution of LifeBy the end of 8th grade, students should know that:• Small differences between parents and offspring can accumulate (through selective breeding) in successive generations so that descendants are very different from their ancestors.• Individual organisms with certain traits are more likely than others to survive and have offspring. Changes in environmental conditions can affect the survival of individual organisms and entire species.

Historical Perspectives - Explaining The Diversity of LifeBy the end of 12th grade, students should know that:• The quick success of Darwin’s book, Origin of Species, published in the mid- 1800s, came from the clear and understandable argument it made, including the comparison of natural selection to the selective breeding of animals in wide use at the time, and from the massive array of biological and fossil evidence it assembled to support the argument.


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Student Learning ObjectivesUpon viewing the video and completing the enclosed student activities, students will be able to do the following:

• Defi ne evolution as a change in a species over time.

• Describe the major components of the theory of natural selection including the aspects of overproduction, competition, variation, adaptations, and selection.

• Defi ne speciation as the evolution of one or more new species from a single existingspecies.

• Understand that a great deal of scientifi c evidence supports the theory of evolution.

• Explain the fossil record as the most complete biological record of life on Earth.

• List one or more examples of anatomical evidence of evolution in living things.

• Describe how the presence of homologous structures and vestigial structures supports evolutionary theory.

• Provide an example of a homologous structure and a vestigial structure.

• Explain that similarities in embryology of many animals point toward the fact that different organisms share a common evolutionary origin.

• Understand that genetic similarities between organisms point out evolutionary relationships.


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Assessment

Preliminary Assessment:The Preliminary Assessment, provided in the Student Masters section, is an assessment tool designed to gain an understanding of students’ pre-existing knowledge. It can also be used as a benchmark upon which to assess student progress based on the objectives stated on the previous pages.

Video Review:The Video Review, provided in the Student Masters section, can be used as an assessment tool or as a student activity. There are two main parts. The fi rst part contains questions that can be answered during the video. The second series of ten questions consists of a video quiz to be answered at the conclusion of the video.

Post Assessment:The Post Assessment, provided in the Student Masters section, can be utilized as an assessment tool following completion of the video and student activities. The results of the Post Assessment can be compared against the results of the Preliminary Assessment to evaluate student progress.


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Introducing the Video

Video Viewing SuggestionsThe student Master “Video Review” is provided for distribution to students. You may choose to have your students complete this Master while viewing the program or to do so upon its conclusion.

The program is approximately twenty minutes in length and includes a ten question video quiz. Answers are not provided to the Video Quiz on the video, but are included in this teacher’s guide. You may choose to grade student quizzes as an assessment tool or to review the answers in class.

The video is content-rich with numerous vocabulary words. For this reason you may want to periodically stop the video to review and discuss new terminology and concepts.

Before showing the program to your students ask them the following question: What evidence exists which supports the evolution of living things? Write the question on the board so all students can see it. Discuss the importance of this question for a couple of minutes. Then ask them for suggestions of types of evidence of evolution of living things.

Next write the following phrases on the board:

Explain to students that these are some of the major categories of evidence supporting evolution. Tell students to pay close attention to the video to learn some more about the specifi cs of each category of evidence. Following the program fi ll in some examples of evidence in each category.

Fossil EvidenceAnatomical EvidenceEmbryological EvidenceGenetic Evidence


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Video Script: Evidence of Change1. If there is one thing that’s certain in nature…2. …and in our lives, its that things change.3. As time goes on our bodies change. When you are young you grow taller and bigger.4. And as we age we gain more experience, more knowledge, and get wiser.5. Things in nature are also constantly changing. For example, the weather and seasons are always changing.6. The interaction of plants and animals with the environment is always changing as well.7. Biologists believe that living things over time have changed a great deal.8. In fact, change is one of the basic themes of the theory of natural selection.9. What causes living things to change?10. How and why do species change?11. And, what evidence exists to support the notion that species change and evolve over time?12. During the next few minutes we’re going to explore these questions and others…13. …and take a look at some of the evidence of the process of change.14. Graphic Transition – Introduction to Theory of Natural Selection15. In 1859 the fi eld of biology was changed forever.16. This was the date when the British naturalist, Charles Darwin, published the earthshaking book titled, The Origin of Species By Means of Natural Selection.17. This book altered the way people thought about living things, and how they change over time.18. The theory of natural selection, proposed by Darwin, is one of the cornerstones of evolutionary theory.19. Evolution is a change in a species over time.20. As you probably already know, a species is a group of organisms that have similar characteristics and successfully reproduce to form fertile offspring.21. The theory of evolution, as other theories about changes in life over time, cannot be conclusively proven or disproven.22. However, a great deal of scientifi c evidence supports the theory of evolution, and during the next few minutes we will examine some of this evidence.23. Graphic Transition – Components of the Theory of Natural Selection24. In 1831, Charles Darwin, serving as naturalist on the ship called the H.M.S. Beagle, took a fi ve-year journey around the world.25. Through visiting places such as South America, the Galapagos Islands, and numerous other islands in the Pacifi c, he gathered a great deal of information which, over the next twenty years, led him to develop the theory of natural selection.


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Script (cont.)26. Natural selection is the survival and reproduction of organisms within a species that are best adapted to their environment. Let’s review the components of the theory of natural selection.27. According to the theory of natural selection, most species produce many more offspring than can survive in nature. This is referred to as overproduction.28. Through the process of overproduction its more likely that a few offspring will survive to adulthood.29. Most plants, for example, produce many more seeds than will ever germinate and grow to reproductive age.30. Animals such as fi sh, frogs, and reptiles also tend to produce large numbers of offspring. 31. Overproduction of offspring often results in competition.32. When resources become scarce individuals are forced to compete for things such as food, living space, 33. …and even breeding partners.34. You Observe! Are all these birds exactly the same? 35. While all the birds, called gannets, may look exactly the same, there are many variations between them.36. Some birds may have slightly longer beaks, some may be heavier, and others may be stronger.37. Minor variations within species of plants and animals are common.38. In some instances a variation possessed by an individual may be advantageous. A variation enabling an organism to be better suited to its environment is called an adaptation.39. A famous study conducted for over twenty years by Rosemary and Peter Grant actually observed competition among fi nches on an isolated island in the Galapagos Islands. 40. They observed that fi nches with beaks best suited for obtaining available food out competed members of the same species when food became scarce.41. This slight variation in beak shape enabled certain fi nches to survive, and pass their beak shape on to their offspring, while those without the variation died.42. The key to Darwin’s theory of evolution is the principle of selection- or as Darwin called it- natural selection.43. You most likely have heard the expression, “survival of the fi ttest.” What does this expression mean?44. This phrase sums up the idea that those individuals with helpful adaptations are more likely to survive, and those without the adaptation will likely die.


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Script (cont.)45. Nature therefore “selects” individuals to survive based on how well adapted they are to their environment.46. In turn, these individuals are able to reproduce, and their offspring tend to have these adaptations as well.47. Graphic Transition – Speciation 48. You Compare! How do these different species of birds compare?49. If you said they all look similar, then you made the same observation Charles Darwin made…50. …when he visited the Galapagos Islands in the 1830’s.51. These birds are called fi nches, often referred to as Darwin’s fi nches.52. These fi nches, of which there are 13 distinct species, . . .53. . . . are one of several pieces of information that caused Darwin to think in a different way about the progression of life.54. The fi nches in the Galapagos serve as an excellent example of speciation. Speciation is the evolution of one or more new species from a single existing species.55. Scientists believe that the fi nches speciated, or evolved, from a single species of fi nch.56. This is a diagram of the likely evolutionary relationship between the different species.57. Let’s now take a look at some of the different types of evidence supporting the theory of natural selection and evolution.58. Graphic Transition – Fossil Evidence59. There is a great deal of scientifi c evidence which supports the theory of evolution.60. One such type of evidence comes from the fossil record.61. As you probably already know, a fossil is the remains or trace of a once-living thing.62. The fossil record is the collection of fossils that scientists have examined and it has taught us a great deal about past life on Earth.63. The fossil record provides a biological record of life on Earth.64. Scientists can determine the age of once living things and also the age of the rocks containing the fossils. 65. Using sophisticated procedures and piecing together millions of fossils, scientists have developed a picture of how life has changed throughout Earth’s history.66. In general, they have concluded that life began in a very simple form, similar to these bacteria, billions of years ago. 67. While the fossil record is not entirely complete, it does. . .68. . . . clearly illustrate the progression of life from single celled organisms to a vast array of organisms found on our planet today.


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Script (cont.)69. Graphic Transition – Anatomical Evidence of Evolution70. You Compare! How are the following structures similar – the wing of this bird, the leg of this cat, and the arm of this person?71. That’s right, these structures all have a similar shape,. . .72. . . . they all have a similar purpose in that they help the organism move,...73. . . . and they also have a similar bone structure.74. Homologous structures demonstrate a similarity due to having shared a common evolutionary ancestor.75. Another type of evidence of evolutionary relationships are vestigial structures. These are structures or remnants of structures that do not have a function, such as the presence of a vestigial toe on this modern day horse.76. Vestigial structures, such as the coccyx, also called your tailbone, are remnant structures that served a function in ancestral organisms.77. Whales and pythons have vestigial hind leg bones embedded in their body, which illustrates that they evolved from four-legged ancestors.78. These are just a few examples of anatomical pieces of evolutionary evidence.79. Graphic Transition – Embryological Evidence of Evolution80. The study of newly formed organisms or embryos and their development is called embryology.81. A comparison of embryology of different organisms provides very interesting evidence of evolution.82. For example, the embryos of many vertebrate animals are quite similar in early stages of development.83. Such similarities point toward the fact that different organisms share a common evolutionary origin.84. Structures such as a tail and gill slits are found in early embryos of fi sh, chickens, and rabbits.85. While fi sh keep their gills, chickens and rabbits lose them as the embryo develops.86. The more closely related the organisms, the longer they resemble each other in their development.87. These similarities in embryology support a strong evolutionary relationship between vertebrate species.88. Graphic Transition – Genetic Evidence of Evolution89. As you may already know, our body cells contain very important genetic information.


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Script (cont.)90. You Decide! What is this substance called?91. DNA is the fundamental unit of heredity and is found in our cells. DNA contains the information all living things need to grow and maintain themselves.92. Advances in technology have enabled biologists to compare the DNA of different organisms, pointing out evolutionary relationships.93. Due to the fact that DNA has been passed down from the earliest organisms, all organisms share commonalities in their DNA.94. The more closely related two different species are, the more similar their DNA. 95. Graphic Transition – Summing Up96. During the past few minutes we have reviewed the fascinating theory of natural selection,. . .97. . . . and learned about some of the evidence that supports the theory of evolution.98. First, we discussed the different components of the theory of natural selection including that of overproduction, competition,. . .99. . . . and the presence of variation between individuals of a species.100. We took a look at how certain variations might prove to be helpful adaptations,. . . 101. . . . and that these adaptations are passed on to offspring.102. Briefl y, we discussed the process of how speciation leads to the development of one or more species from a single species.103. We then explored some of the evidence supporting the theory of evolution. . . 104. . . . including fossil evidence, . . . 105. . . . embryological evidence, . . .106. . . . genetic evidence, . . .107. . . . and anatomical evidence.108. So the next time you wonder about how the abundance of life around us evolved,... 109. . . . or how life has changed through time,...110. ...think about some of the aspects of the theory of evolution and the evidence supporting it.111. You just might think about life on Earth a little differently.112. Graphic Transition – Video Assessment113. Fill in the correct word to complete the sentence. Good luck and let’s get started.

1. _________ is a change in a species over time.2. Natural _________ is the survival of organisms best adapted to their environment.


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Script (cont.)3. __________ is the evolution of one or more new species from a single existing species.4. The theory of evolution is supported by __________ evidence.5. The ______ record provides a biological record of life.6. Fossils clearly point out the progression of life from ______ organisms to advanced organisms.7. ________ structures demonstrate a similarity due to having shared a common evolutionary ancestor.8. Your coccyx is an example of a _________ structure.9. Early _________ of many vertebrates is quite similar.10. Closely related species have similar _____ sequences.

Answers may be found on page 17.


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• The Evolution of the Horse

• Embryological Evidence

• Vestigial Structures

• Vocabulary of Evidence of Change

Student Assessments and ActivitiesAssessment Masters:

• Preliminary Assessment

• Video Review

• Post Assessment

Student Activity Masters:


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Answers to Student AssessmentsPreliminary Assessment (pgs. 20-21)

1. Evolution 2. selection 3. Speciation 4. scientifi c 5. fossil 6. simple 7. Homologous 8. vestigial 9. embryology 10. DNA

Video Review (pg. 22)

Post Assessment (pgs. 23-24)

Video Quiz (p. 22)

1. Evolution 2. Darwin 3. adaptations 4. fossil 5. complex 6. Homologous 7. vestigial 8. Embryological 9. longer 10. DNA 11. F 12. T 13. F 14. F 15. T 16. F 17. T 18. T 19. T 20. T

1. Embryological 2. fossil 3. Evolution 4. Homologous 5. Darwin 6. longer 7. adaptations 8. DNA 9. vestigial 10. complex 11. F 12. F 13. T 14. T 15. T 16. F 17. T 18. T 19. F 20. T

1. No, the birds are not all exactly the same. They all have slight variations among them including different coloring, beak length, strength, etc.2. All of the different species of fi nches look similar, however each is a different species. There are 13 species of Galapagos fi nches.3. The structures are similar in shape, purpose, and bone structure, but each has a somewhat different function.4. The substance containing our important genetic information is called DNA.


Evidence of Change

Answers to Student Activities

Vocabulary of Evidence of Change (p. 30)

Embryological Evidence (p. 26 - 28)

The Evolution of the Horse (p. 25)

Vestigial Structures (p. 29)

1. d - speciation 2. h - vestigial structures 3. b - overproduction 4. f - fossil record 5. j - DNA 6. a - theory of natural selection 7. i - embryology 8. g - homologous structures 9. e - isolation 10. c - adaptation

1. The fi rst equine organisms looked a lot more like dogs than horses. They had feet with several toes and they were only one and a half feet tall.

2. Horses moved out of the forests millions of years ago because the forests were shrinking in size, and they could survive more easily on grasslands.

3. The fossil evidence of the evolution of the horse is very important because it showsus evidence that evolution happened on a large scale, over periods of millions of years.

Questions1. In the 1700s, scientists were fascinated by the observation that different animals looked very similar in their early stages of development.2. Embryology is the study of early developmental stages of living things (embryos).3. Early embryos of fi sh, reptiles, birds, and mammals have tails and gill slits.4. As the embryos become more developed they become less and less alike.5. The embryos of different organisms help scientists identify evolutionary relationships. The greater the embryological similarity, the closer the evolutionary relationship of different organisms.

1. This illustrates a pelvis in a whale. This is a vestigialstructure because whales do not need a pelvis toswim. It suggests that whales evolved fromvertebrates which walked on land.

2. This illustrates the coccyx, or tailbone in humans. It suggests a common ancestry with vertebrates which possess tailbones.

3. This is an appendix. In humans it is useless but inother animals it aids in the digestion of cellulose. It suggests a common ancestry to other vertebrates such as other primates.

tailtail

tail

tail

tail

tail

tail

tail

tail

rabbit chicken fi shgills

gills

gills

gills

gills


Evidence of Change Assessment and Student

Activity Masters

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NameEvidence of Change

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Directions: Fill in the blank with the correct word. A list of possible answers is provided at the bottom of the page.

Preliminary Assessment

1. _____________ is a change in a species over time.

2. Charles ________ published the book titled The Origin of Species By Means of Natural Selection.

3. Individuals with helpful _____________ are more likely to survive.

4. The ________ record is the most complete biological record of life on Earth.

5. Fossils show that life was quite simple billions of years ago, and has become more _________ .

6. _____________ structures are similar in structure and origin but have a somewhat different function.

7. The presence of the coccyx (tailbone) in humans is an example of a ___________ structure.

8. _______________ similarities of many vertebrate animals in early developmental stages point toward a common evolutionary origin.

9. The more closely related the organisms, the ________ they resemble each other in their development.

10. The more closely related two different species are, the more similar their _____.

longeradaptationsHomologousfossilEvolution

DarwincomplexEmbryologicalDNAvestigial

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Directions: Decide whether the statement is true (T) or false (F).

Preliminary Assessment

T F11. All members of a single species have exactly the same traits.

12. Change is one of the most fundamental principles of the theory of natural selection.

13. Charles Dickens wrote The Origin of Species By Means of Natural Selection in 1859.

14. The expression “survival of the fittest” means that only animals who exercise a lot will live to adulthood.

15. The 13 different species of finches on the Galapagos Islands provide an example of speciation.

16. If members of two different species have homologous structures, then they definitely don’t have common ancestors.

17. Examples of vestigial structures include the tailbone in humans, and embedded hind leg bones in whales.

18. Embryos of many vertebrate animals look quite similar in early stages of development.

19. Fossils show us how life has changed throughout Earth’s history.

20. Organisms which are similar to one another have similar DNA.

T F

T F

T F

T F

T F

T F

T F

T F

T F

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Video ReviewDirections: During the course of the program, answer the questions as they are presented in the video. At the end of the video, answer the Video Quiz questions.

You Observe! 1. Are all these birds exactly the same?

You Compare! 2. How do these different species of birds compare?

You Compare! 3. How are the following structures similar - the leg of this cat, the wing of this bird, and the arm of this person?

You Decide! 4. What is this substance called?

Video Quiz:

1. ___________ is a change in a species over time.

2. Natural ____________ is the survival of organisms best adapted to their environment.

3. _____________ is the evolution of one or more new species from a single exisiting species.

4. The theory of evolution is supported by _______________ evidence.

5. The ________ record provides a biological record of life.

6. Fossils clearly point out the progression of life from ________ organisms to advanced organisms.

7. ________ structures demonstrate a similarity due to having shared a common evolutionary ancestor.

8. Your coccyx is an example of a ___________ structure.

9. Early ____________ of many vertebrates is quite similar.

10. Closely related species have similar _____ sequences.

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Post AssessmentDirections: Fill in the blank with the correct word. A list of possible answers is provided at the bottom of the page.

1. _______________ similarities of many vertebrate animals in early developmental stages point toward a common evolutionary origin.

2. The ________ record is the most complete biological record of life on Earth.

3. _____________ is a change in a species over time.

4. _____________ structures are similar in structure and origin but have a somewhat different function.

5. Charles ________ published the book titled The Origin of Species By Means of Natural Selection.

6. The more closely related the organisms, the ________ they resemble each other in their development.

7. Individuals with helpful _____________ are more likely to survive.

8. The more closely related two different species are, the more similar their __________ .

9. The presence of the coccyx (tailbone) in humans is an example of a ___________ structure.

10. Fossils show that life was quite simple billions of years ago, and has become more _________ .

EvolutionDarwinadaptationsfossilcomplex

HomologousvestigialEmbryologicallongerDNA

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Post AssessmentDirections: Decide whether the statement is true (T) or false (F).

11. Charles Dickens wrote The Origin of Species By Means of Natural Selection in 1859.

12. If members of two different species have homologous structures, then they definitely don’t have common ancestors.

13. Fossils show us how life has changed throughout Earth’s history.

14. Change is one of the fundamental principles of the theory of natural selection.

15. Examples of vestigial structures include the tailbone in humans, and embedded hind leg bones in whales.

16. All members of a single species have exactly the same traits.

17. The 13 different species of finches on the Galapagos Islands provide an example of speciation.

18. Organisms which are similar to one another have a similar DNA.

19. The expression “survival of the fittest” means that only animals who exercise a lot will live to adulthood.

20. Embryos of many vertebrate animals look quite similar in early stages of development.

T F

T F

T F

T F

T F

T F

T F

T F

T F

T F

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The Evolution of the HorseDirections: Read the information below and answer the questions.

One of the most vivid examples of evolution over a long period of time involves that of the horse. Scientists, using the fossil record, trace the ancestry of the horse back more than 55 million years ago. These fi rst equine (or horse-related) animals actually looked a lot like dogs! They stood only about one and a half feet tall, they had three toes, and they foraged for food like fruit and soft vegetation.

One of the most important things to remember when studying the evolution of the horse is that it didn’t occur in a linear fashion. There were many different types of species that didn’t survive. For example, a version of the more primitive horse continued browsing in the forests while others moved out onto the plains, and survived for several million years. Nor was it a steady process; there were times when great change occured in a relatively short period of time, and also millions of years when a species existed without major change. The fossil evidence showing changes in the horse proves that evolution happened over long periods of time. The story of the evolution of the horse is just one example among thousands illustrating the evolution of living things.

Over time, these ancient horses evolved to adapt to changes in their environment. About 24 million years ago the forests began shrinking, and the horses moved out onto the more prevalent grasslands. Due to this change in habitat, traits that we can still recognize today began to take shape. Horses’ teeth grew harder so they could eat the tougher fi bers of grasses that grew on the plains. They also developed specialized running muscles, and longer legs with stronger bones to support the force of running. Finally, their extra toes diminished to the vestigial structures that still exist on modern horses today.

Questions:1. What did the fi rst equine organisms look like?

2. Why did horses move out of the forests millions of years ago?

3. Why is the fossil evidence of the evolution of the horse so important?

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Embryological EvidenceBackground: In the 1700s scientists were fascinated by the observation that different animalslooked very similar in their early stages of development. They noticed that as differentorganisms develop they become less and less alike. Scientists today still compare thedevelopmental stages of animals of different species to help identify evolutionary relationships. The study of the early developmental stages of living things is called embryology. An embryo is an early stage of a living thing. In most vertebrate animals, embryos develop inside the mother. Comparison of early embryos, particularly those of vertebrates, illustrates remarkable similarities. For example, early embryos of fish, reptiles, birds, and mammals all have tails and gill slits. Fish keep the gills as they develop, while the other vertebrates lose them. In humans, the tail disappears in later stages,but in other vertebrates such as fish, birds, and reptiles, the tail remains. Similarities in embryology of different living things suggest strong evolutionaryrelationships. Scientists often study the embryology of different organisms to help understand their evolutionary relationships. Embryological evidence suggests many animals share a common ancestry- the more closely associated the embryology of different organism, the closer their evolutionary relationship.

Materials: worksheet titled “Embryological Evidence,” scissors, glue or gluestick, pencil

Directions:1. Obtain the materials listed above from your instructor.2. Take a minute to study the worksheet titled “Embryological Evidence.” The diagram illustrates some of the embryological stages of three different vertebrate organisms: fish, rabbit, and chicken. These diagrams are not arranged in the sequence according to the development of the organism.3. Your task is to arrange the organisms in the correct sequence based on their development. First carefully cut out each organism and place it on a piece of paper.4. Arrange the developmental stages of the rabbit in a column starting with the earliest stage at the top of the column. Do the same for the chicken and fish next to the column of the rabbit.5. Glue the organisms to the pages once you have correctly arranged them.6. Label the tail and gill slits of each organism.7. Answer the questions on the worksheet titled “Embryological Evidence Questions.”

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Embryological Evidence

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Embryological Evidence Questions1. What did scientists in the 1700s notice about the early stages of development in some living things?

2. What is embryology?

3. List some of the similarities among embryos of vertebrate animals.

4. What do you notice about the embryos you worked with as they became more developed?

5. How is embryology important to the study of evolutionary relationships?

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Vestigial StructuresBackground:

Some living things, including humans, have organs or structures with no apparent function. For example, some snakes possess the remnants of hind legs and a pelvis embedded in their body. Manatees are animals which live their lives in the water, but retain the bones of a pelvis that are found in land dwelling vertebrates. These are just a couple examples of what scientists call vestigial structures.

A vestigial structure is a body part of an organism that tends to be reduced in size and does not seem to have a function. It is thought that vestigial structures are parts or organs that once functioned in the ancestors of organisms. While the part had an important function in the ancestor, it lost its usefulness in the new organism. For this reason, vestigial structures are considered a valuable piece of evolutionary evidence.

Directions: Below are three different diagrams illustrating vestigial structures. Next to each diagram, identify the vestigial structures and describe why it is considered a vestigial structure. Also state its evolutionary signifi cance.

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2.

3.

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Vocabulary of Evidence of ChangeDirections: Unscramble the vocabulary words in the first column. Match the words to the definitions in the second column.

____ 1. peainscito ____________

____ 2. vsiiletga tutrssrcue ___________ ____________

____ 3. vrrdcinoepouto _______________

____ 4. oslfsi eodrcr

________ _________

____ 5. NDA

________

____ 6. hoyter fo auantrl eetoslcin ______ __ ________ ________

____ 7. mrooyebylg ____________

____ 8. ooooshmlgu tutrssrcue ____________ _____________

____ 9. sltoioain ___________

____ 10. aaodtinapt ___________

a. the survival and reproduction of organisms within a species that are best adapted to their environment

b. a practice held by many species of producing many more offspring than can survive

c. characteristic that can enable an organism to survive more easily

d. the evolution of one or more new species from a single existing species

e. the separation of two or more groups within a species, prohibiting breeding between groups

f. the most complete biological record of life on our planet

g. body parts that are similar in structure and origin but have somewhat different functions

h. body structures or remnants of structures that do not have a function

i. the study of newly formed organisms or embryos and their development; can reveal evolutionary similarities

j. the fundamental unit of heredity that is found in all of our cells

Documents

Evidence of Change Guide - Continuing Strong Foundations …secondary.mysdhc.org/science/documents/FCIMS/Life/L… · · 2009-07-31Our videos and accompanying materials focus on