Changes in Species Over Time

Transcription

1 Changes in Species Over Time Name: Hr:

2 Embryology

3 Evolution- Changes in Species Over Time VOCAB Fossils- An imprint or remains of plants or animals that existed in the past. Radioactive Dating- Method based on radioactive elements used by scientists to measure the age of fossils or the age of the rocks in which fossils are found. Half-Life- Time it takes for half of a radioactive element to decay. Sedimentary Rocks- Type of rock formed from layers of mud and sand that harden slowly over time. Law of Superposition- Law that states that in a series of sedimentary rock layers, younger rocks normally lie on top of older rocks. Fossil Record- Most complete biological record of Life on Earth. Adaptation- Changes that increase an organism s chances of survival. Homologous Structures- Structures that evolved from similar body parts. Molecular Clock- Scale used to estimate the rate of mutations over time. Natural Selection- The survival and reproduction of those organisms best adapted to their surroundings. Adaptive Radiation- Process in which one species evolves into several species, each of which fills a different niche. Punctuated Equilibrium- Periods in Earth s History in which many adaptive radiations occur in a short period of time. Gradualism- Organisms evolve through a process of slow and constant change. 1

4 Chapter 25 Section 25-1 (pg ) 1. is the change in species over time. 2. Describe Evolution in your own words 3. In which Era did the first amphibians appear? (Table Pg. 632). Mammals?. Section 25-2 (pg ) 1. A is the remains or evidence of a thing. 2. Most fossils are not organisms. Fossils are generally incomplete because only the parts of dead plants and animals become fossils. 3. A method used by scientists to measure the age of fossils or the age of rocks in which fossils are found is called. 4. The - of an element is the time it takes for half of the element to decay. 5. Suppose a radioactive element has a half-life of 30 days. Of an 8g sample, how much will be unchanged after 90 Days?. 6. are made of layers of sediments that have piled up one atop the other. Small rocks, shells and other materials. 7. The Law of Superposition states that 2

5 8. All the fossil evidence scientists have collected forms what is known as the. This recording is the most complete biological record of life on earth. 9. Changes that increase an organism s chances of survival are called. 10. ****Organisms that are better adapted to their environment do more than just survive. They should be able to produce. 11. Ancestral Body parts that are similar in structure are called. 12. Another type of evidence is based on, or the study of developing organisms. Comparing embryos can show us how closely related species are. 13. Scientists have developed a scale that can be used to estimate the rate of change in proteins over time called the. 14. What are some of the differences between Neanderthals and Cro-Magnons? Section 25-3 (pg ) 1. is the survival and reproduction of those organisms best adapted to their surroundings a. of offspring results in competition for food or shelter among the different members of a species. b. Over time the will become the norm as those members of the species with the variations survive in greater numbers. 2. Describe how living things can become a mirror of the changes in their environment. 3

6 Section 25-4 (pg ) 1. The process in which one species evolves into several species, which fill different niches, is called. 2. According to, there may be periods in Earth s history in which many adaptive radiations occur in a relatively short period of time. 3. What is mass extinction? And how is it related to punctuated equilibrium? 4. In what ways does the fossil record support punctuated equilibrium? 4

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8 The Fossil Record In the fossil record, an intermediate form is a fossil that shows some characteristics of an earlier related organism and some characteristics of a later related organism. The illustrations below show organism whose fossils make up part of the fossil record. The organism are in order from oldest (#1) to most recent (#4). Draw an animal that might have been an intermediate form between organism 1 and organism 2. Then, draw an animal that might have been an intermediate form between organism 3 and organism 4. Describe one change you see between organism one and the other organisms. How might these fossils provide evidence of evolution? 6

9 Evolution of Goobers Goobers are a funny group of organism that live in Mr. Cagle s desk drawer. Use the picture below to explain how adaptations of Goobers are passed on from generation to generation. What trait do you think is the most adaptive for the survival of Goobers in their desk drawer environment? Why is that trait an adaptation? Using Darwins four steps of Natural Selection explain how this adaptation is passed on from parent to offspring? What do you think a Goober will look like after a few generations? Draw a Goober below What would have to the Goobers if the food source were to be lowered a tremendous distance (a few inches)? How would Lamarck explain the Goobers adaptation? 7

10 Peppered Moth Simulation Objectives: Describe the importance of coloration in avoiding predation Relate environmental change to changes in organisms Explain how natural selection causes populations to change Materials Sheet of white paper 30 newspaper circles (made with hole Newspaper punch) Forceps 30 white circles (made with hole Colored Pencils punch) Clock with Second Hand Purpose: In this lab, you will simulate how predators locate prey in different environments. You will analyze how color affects and organism's ability to survive in certain environments. Industrial Melanism is a term used to describe the adaptation of a population in response to pollution. One example of rapid industrial melanism occurred in populations of peppered moths in the area of Manchester, England from 1845 to Before the industrial revolution, the trunks of the trees in the forest around Manchester were light grayish-green due to the presence of lichens. Most of the peppered moths in the area were light colored with dark spots. As the industrial revolution progressed, the treee trunks became covered with soot and turned dark. Over a period of 45 years, the dark variety of the peppered moth became more common. 8

11 Procedure. 1. Place a sheet of white paper on the table and have one person spread 30 white circles and 30 newspaper circles over the surface while the other person isn't looking. 2. The "predator" will then use forceps to pick up as many of the circles as he can in 15 seconds. 3. This trial will be repeated with white circles on a newspaper background, newspaper circles on a white background, and newspaper circles on a newspaper background. Record the data in chart below. Starting Population Number Picked up Trial Background Newspaper White White Newspaper 1 white white newspaper newspaper Analysis 1. What did the experiment show about how prey are selected by predators? 2. What moth coloration is the best adaptation for a dark (newspaper) background? How do you know? 3. What would you expect the next generation of moths to look like after trial 1? What about the next generation after trial 3? 4. How does the simulation model natural selection? 5. Examine the table and construct a graph. Plot the years of the study on the X- axis, and the number of moths captured on the Y axis. You should have 2 lines on your graph - one for light moths, and one for dark moths. 9

12 Year # of Light Moths Captured # of Dark Moths Captured 6. Explain in your own words what the graph shows. 7. Describe a situation where this type of selection might occur. 10

13 Woolybooger natural selection Materials 3 bags of beans (northern or lima) 10 trays 10 clothespins 10 plastic spoons 10 tweezers 10 dissecting needles Introduction. On a distant planet there exists 5 species of a creature called a Woolybooger. Each Woolybooger is similar except their mouth has variations. All woolyboogers eat beans. Some woolyboogers have a clothespin mouth (demonstrate how to use the clothespin to pick up beans). Some woolyboogers have a tweezer mouth (demonstrate), some have a needle mouth (demonstrate). One year a new species of woolybooger was discovered, this woolybooger was called the Spoon-Mouthed Woolybooger (demonstrate). Each of you will play the part of a woolybooger on this planet. The spoon-mouth wooly booger is rare, so only two of you will get to be this type of wooly booger. Equipment for each group - 4 students (flexible) Each group has a tray to share with beans but each student will have their own utensil. Avoid "cheating", this would be using the utensil in anyway other than the ways that were shown. Procedure: 1. You will run through several trials. 2. Each trial will require your woolybooger to gain at least 20 beans. 3. If 20 beans are not acquired during the time period, your woolybooger has died st trial will be 1 minute, 2 nd trial will be 45 seconds, 3 rd trial will be 30 seconds and the 4 th trail 15 seconds 5. When a woolybooger dies, that student can play the offspring of the surviving woolyboogers. They will get a new utensil for the next trial. 11

14 Discussion Questions: 1. What happens to animals that cannot compete as well with other animals in the wild? 2. Can you think of any real-life examples of the woolybooger, where one species has a definite advantage over another? 3. Sometimes animals that are introduced into an area that they never lived in before, happens? out-compete and endanger resident species, why do you think this 4. 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? 5. How do you think diseases can affect natural selection? 12

15 Examining the Fossil Record Objectives: analyze characteristics of fossils compare placement of fossils and determine relative ages develop a model evolutionary tree based on the morphology and age of fossils Background Fossils are traces of organisms that lived in the past. When fossils are found, they are analyzed to determine the age of the fossil. The absolute age of the fossil can be determined though radiometric dating and determining the layer of rock in which the fossil was found. Older layers are found deeper within the earth than newer layers. The age and morphologies (appearances) of fossils can be used to place fossils in sequences that often show patterns of changes that have occurred over time. This relationship can be depicted in an evolutionary tree, also known as a phylogenetic tree. There are two major hypotheses on how evolution takes place: gradualism and punctuated equilibrium. Gradualism suggests that organisms evolve through a process of slow and constant change. For instance, an organism that shows a fossil record of gradually increased size in small steps, or an organism that shows a gradual loss of a structure. Punctuated equilibrium suggests that species evolve very rapidly and then stay the same for a large period of time. This rapid change is attributed to a mutation in a few essential genes. The sudden appearance of new structures could be explained by punctuated equilibrium. Speciation The fossil record cannot accurately determine when one species becomes another species. However, two hypotheses regarding speciation also exist. Phyletic speciation suggests that abrupt mutations in a few regulatory genes occur after a species has existed for a long period of time. This mutation results in the entire species shifting to a new species. Phyletic speciation would also relate to the Punctuated Equilibrium hypothesis regarding evolution. Divergent speciation suggests that a gradual accumulation of small genetic changes results in subpopulation of a species that eventually accumulate so many changes that the subpopulations become different species. This hypothesis would coincide with the gradualism model of evolution. Most evolutionary biologists accept that a combination of the two models has affected the evolution of species over time. 13

16 Procedure: 1. The diagram you are creating requires a large space. To create your workspace, tape together 8 sheets of standard sized paper. Use a ruler to draw the following chart on your workspace Time Period ( 2 1/2 inches wide) Began (years ago) ( 2 1/2 inches wide) Fossils (8 inches wide) Wyomington (oldest) 995,000 (Each row here must be 4 inches tall) Ohioian 745, 000 Nevadian 545,000 Texian 445,000 Oregonian 395,000 Coloradian 320,000 Montanian 170,000 Californian 80,000 Idahoan (the present) 30, The group of "fossils" you will work with are fictitious animals. Each fossil on your sheet is marked with a time period. Cut out each fossil and make sure you include the time period marked below it. 3. Arrange the fossils by age. On your data chart, place each fossil next to the period from which the fossil came from. The term "upper" means more recent and should be placed lower in the row. The term "lower" means an earlier time period, fossils from a "lower" time period should be place toward the older time periods. In each fossil column, you may have 3 specimens, one from the main time period, one from the upper and one from the lower. Not all fossils are represented, illustrating the incompleteness of any fossil record. 4. While keeping the fossils in the proper age order, arrange them by morphology (appearance). To help you understand the morphology of the specimen, view the diagram. Arrange the fossils using the following steps. a. Center the oldest fossil at the top of the fossil column (toward the oldest layer) 14

17 b. Through the chart, those fossils that appear to be the same (or close to the same) as the fossils preceding them should be placed in a vertical line c. During a certain period, the fossils will split into two branches. In other words, one fossil from that period will show one type of change, and another fossil will show a different change. When this happens, place the fossils side by side in the appropriate time period. From this point on you will have two lineages? 5. Once all the fossils have been placed correctly according to time and morphology, tape or glue the fossils in place. Analysis 1. Give a brief description of the evolutionary changes that occurred in the organism. 2. During which time period did the fossils differentiate into two branches? 3. Explain how the chart illustrates both punctuated equilibrium and gradualism. Use specific fossils from the chart to support your answer. 4. Making the assumption that each fossil represents a separate species. Explain how the chart illustrates divergent and phyletic speciation. Use specific fossils from the chart to support your answer. 5. Define the following terms: morphology fossil phylogenetic tree 6. Examine the fossil that was unearthed in a museum, apparently the labels and other information were lost. Using your fossil record, determine the time period this fossil is likely from. Explain your reasoning. 7. Of the two major species that arose from the parent species, which was more successful? How do you know? 8. For each of the blanks on your fossil record, draw in what the organism appearance is likely to be. Draw this directly on your fossil record. 15

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21 Evidence of Evolution Objectives: To learn about homologous, analogous and vestigial structure Material: Colored Pencil Homologous Structures 1. Examine the drawing of the bones 2. Color each part of the human arm a different color. All the bones of the wrist should be a single color, the bone groups of the hand should be a different single color. 3. Then color the corresponding bone in each of the other animals the same color as the human bone. a. Describe the function of each set of bones below. Do this in the table 19

22 Animal Human Cat Whale Bat Frog Lizard Bird Function of set of bones b. Are the bones arranged in a similar way in each animal? State the evidence from your observations in your answer. These structures are formed in similar ways during time the individual develops and share like arrangements, however, they have somewhat different forms and functions. They are called homologous structures. Analogous Structures 1. Examine the butterfly wing and the bird wing a. What function do these structures share? b. How do they differ in structure? 20

23 c. Do birds and insect share any structural similarities that would suggest they are closely related? Some apparently unrelated animals have organs with similar functions, yet very different structure and form. These structures are called analogous structures. Vestigial Structures Gradual changes have occurred through time that have in some cases reduced or removed the function of some body structures and organs. The penguin s wings and the leg bones of snakes are example of this phenomenon. 1. The cave fish and minnow shown are related, but the cave fish is blind. a. Explain why eyesight is not an important adaptation to life in a cave? b. Does the appearance of the cave fish and the minnow suggest common ancestry? Why? Organs or structures that have lost their function in the organism and become reduced in size (because of efficiency) are called vestigial structures. 2. Read the list of human vestigial structures shown in Table c. Suggest a possible function for each structure and explain why it became vestigial. 21

24 Structure Possible Function Why Vestigial Appendix Coccyx (tail bone) Muscles the move ears Muscles that make hair stand up Little toe Wisdom teeth Analysis and Interpretations 1. Explain why the homologous structures in Part 1 are evidence of evolutionary relationships. 2. Explain the evolutionary relationship between the fin of a fish and the flipper of a whale. 22

25 Embryology development or ontogeny All vertebrate embryos follow a common developmental path due to their common ancestry. All have a set of very similar genes (homeobox genes) that control the basic body plan. As they grow, the differences that will distinguish the embryos as adults become more and more apparent. The study of this development (ontogeny) can yield insights into the process of evolution. Coloring Assignment This illustration is of six developmental stages (from left to right) of five species of vertebrates - one amphibian (salamander), one bird (chicken), and three mammals ( pig, monkey, and human). As you color, note the similarities of body shapes among the five species in the early developmental stages. The late fetal/newborn/adult stages reflect the emergence of species-specific body plans as a result of differential growth. 1. Color the vertical arrow representing phylogeny gray. 2. Color the horizontal arrow representing ontogeny blue. 3. Color the title Fertilized Egg beginning at the bottom (salamander) and working up (human) new color (your choice). 4. Continue coloring the forms (b) through (f) and their titles, left to right, beginning each stage at the bottom of the plate and working up. 5. Use contrasting colors for the different stages. 23

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27 Analysis and Interpretation 1. Compare and contrast the fertilized eggs of the five organisms. 2. Compare and contrast the late cleavage stage of the five organisms. 3. How do the three mammals compare at the body segment stage? 4. Notice the gills slits are visible at the body segment stage in the humans. Is this also true for the monkey and pig? Where are our gill slits now? 5. What is the umbilicus see n in the limb bud stage of the human? Which of the organisms do not have this structure? And why not? 6. Compare and contrast the limb bud stage of the five organisms. 7. Compare and contrast having a tail with the five organisms. 8. What is the cause of the common way the embryos develop? 9. What is ontogeny? 25

28 DARWINS EVOLUTION PRACTICE Read the following situations below and identify the 5 points of Darwin s natural selection. 1) There are 2 types of worms: worms that eat at night (nocturnal) and worms that eat during the day (diurnal). The birds eat during the day and seem to be eating ONLY the diurnal worms. The nocturnal worms are in their burrows during this time. Each spring when the worms reproduce, they have about 500 babies but only 100 of these 500 ever become old enough to reproduce. a. What worm has natural selection selected AGAINST? FOR? Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. Some variations are favorable. More offspring are produced that survive. Those that survive have favorable traits. A population will change over time. 2) There are 3 types of polar bears: ones with thick coats, ones with thin coats and ones with medium coats. It is fall, soon to be winter. The temperatures are dropping rapidly and the bears must be kept warm, or they will freeze to death. Many of the bears have had ~2 cubs each but due to the extreme temperatures, many mothers only have one cub left. a. What bear will natural selection select AGAINST? FOR? Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. Some variations are favorable. More offspring are produced that survive. Those that survive have favorable traits. A population will change over time. 26

29 3) In ostriches, there are 2 types: ones that run fast and those that run slowly. The fast birds can reach up to 40 miles an hour. Jackals love to eat ostrich, and they can reach speeds of up to miles per hour. A flock of ostrich will lay ~ 10 eggs (each mother only lays 1), but many rodents break into the eggs and eat the fetus before they hatch. a. What ostrich will natural selection select AGAINST? FOR? Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. Some variations are favorable. More offspring are produced that survive. Those that survive have favorable traits. A population will change over time. 4) There are two types of rabbits: those that strictly eat grass and those that strictly eat berries and flowers. A drought occurs one year, and the plants have difficulty producing any extras (flowers, berries, etc.). They can only try and keep themselves green. The rabbits have had babies all year long but many are eaten by foxes or hawks Due to the drought, many have starved to death. a. What rabbit will natural selection select AGAINST? FOR? Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. Some variations are favorable. More offspring are produced that survive. Those that survive have favorable traits. A population will change over time. 5) Bob believes that giraffes have long necks because they have stretched their necks to try and reach food that is high in trees. Since the parent had stretched its neck, it passed the long neck on to its offspring. Ryan believes that giraffes have long necks because the ones with long necks were able to reach the food, and those with short necks could not and died. The long necked giraffes reproduced, and soon all of the giraffes had long necks. a. Who thinks like Lamarck? b. Who thinks like Darwin? _ 27

30 Changes Over Time Review 28

31 Across 2. structures that are similar 5. a characteristic that helps an organism survive 9. when one species evolves into many; adaptive 10. pattern of evolution where a species is stable for a long time then rapidly changes; equilibrium 12. the name of Darwin's book; the of species 13. process by which evolution occurs; natural 17. had different shaped shells depending on the island they were from 18. well-supported testable explanation 20. when two species evolve together 21. natural selection is also known as the survival of the 22. islands that Darwin visited 23. principle that states that living species are descended from ancient ones; descent with 24. the name of the ship that darwin traveled on Down 1. when two unrelated organisms look alike (sharks & dolphins) 3. refers to the variety of living things 4. when organisms disappear from the earth 6. proposed the theory of evolution by natural selection 7. formation of new species 8. change over time 11. required for new species to form 14. preserved remains of ancient organisms 15. had different shaped beaks depending on the island they were from 16. the study of the earth 19. structures that have no current function Word Bank Vestigial Selection Origin Punctuated Geology Finches Fossils Isolation Radiation Adaptation Homologous Evolution Speciation Darwin Extinction Diversity Convergent Turtles Beagle Modification Theory Coevolution Fittest Galapagos 29

32 Goals/ Reflection My goal for this packet is.. This is my goal because. What was your favorite unit, so far, in Science? Why? 30

33 What was your least favorite? Why? If there was 1 curriculum related item you would change, what would it be, and how would you change it? 31

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