Homework answers / question archive / To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas BIO 101 Lab 11: Human Evolution and Natural Selection Simulations Notification: If you have a disability that makes it difficult to complete this lab, please contact your instructor

To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas BIO 101 Lab 11: Human Evolution and Natural Selection Simulations Notification: If you have a disability that makes it difficult to complete this lab, please contact your instructor

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To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas BIO 101 Lab 11: Human Evolution and Natural Selection Simulations Notification: If you have a disability that makes it difficult to complete this lab, please contact your instructor. Please provide your instructor a copy of the Memorandum of Accommodation (MOA) from NVCC Disability Support Services. Objectives: • • • • Identify, compare, and contrast the hominid skulls provided Describe the structural homologies of vertebrates Describe the developmental homologies of craniates Discuss the effects of environment and predation on natural selection Background: Evolution is the change in frequency of heritable characteristics in a population over the course of generations. Many factors shape the evolution of populations and development of new species. For example, the environmental conditions can dictate which prey animals survive more often and which predators are more successful. As environments are naturally or artificially altered certain characteristics or phenotypes within a population become more favorable for survival and reproductive success. It is key to remember that evolution does not move towards perfection of a population, but rather towards the blend of characteristics that fit best in the current environment. Additionally, evolution occurs over the span of generations. Therefore, populations with faster generation times, such as bacteria, will evolve faster to environmental changes than organisms with slower generation times, such as humans. There are major questions in the field of evolution. The origin of modern humans is of great interest. What did our ancestors look like? Fossil records and close living relatives, like the chimpanzee, offer details about modern human evolution. The great apes (chimpanzees, gorillas, and orangutans), humans, and other hominids all share a common ancestor. The different species arose through adaptive radiation, where a common ancestral species gave rise to many different species (Figure 1). BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 1 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas With respect to modern human evolution, the current hypothesis is called the “out-of-Africa” hypothesis (Figure 2). Simply stated, it proposes that modern humans, Home sapiens, evolved in Africa then migrated across the continents of the world. DNA, fossil, and, archeological evidence support this hypothesis. DNA and fossil evidence also indicate that migrating modern humans (Homo sapiens) lived in the same areas and interbred with other hominds, such as Homo neanderthalensis (Neanderthals). Full genome analyses show that most Europeans and Asians have between 1 and 2 percent Neanderthal DNA in their genomes. Individuals indigenous to sub-Saharan Africa have none, or very little, Neanderthal DNA because their ancestors did not migrate out of Africa. Species Australopithicus africanus Homo erectus Homo neanderthalensis Homo sapiens (Cro-Magnon) Homo sapiens (modern) Alive on Earth 3,000,000 – 2,300,000 years ago 1,800,000 – 500,000 years ago 200,000 – 35,000 years ago 200,000 – 40,000 years ago 200,000 years ago – present BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 2 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas In this lab exercise you will perform a comparative analysis of hominid skulls, craniate embryos, and vertebrate forelimbs. You can use this data to infer evolutionary connections among species. Additionally, you will simulate a natural selection process to assess the effects of the environment on prey and predator populations. Materials: • Internet • Calculator Safety: Follow all standard laboratory safety procedures. Procedure: Skull analysis at the “Archaeology Dig Site” 1. Watch the following video describing how skull measurements are made from time 0:00 to time 7:36 https://www.youtube.com/watch?v=Gw6fB0CObwo 2. Observe the images below and note the following differences: how pronounced the brow ridges are in each skull, how long the canine teeth are in each skull, and how sloped the forehead is in each skull. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 3 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 3. Rate the following characteristics of each skull on a scale from 1 to 5 and record your observations in Table 1. a. Brow ridges 1 not at all pronounced 2 3 somewhat pronounced 4 5 very pronounced 2 3 somewhat longer than nearby teeth 4 5 a lot longer than nearby teeth 2 3 somewhat sloped 4 5 very sloped b. Length of canine teeth 1 not any longer than nearby teeth c. Forehead 1 not at all sloped 4. Based on the Background information, the values you entered in Table 1, and the video you watched, answer Question 1 in the Lab Worksheet 5. In the laboratory, you would make several measurments (in centimeters) of each skull using a meter stick and calipers. These measurements would be used to calculate key features of the skulls. The images below show where the measurements are in relation to the shape of a skull. These measurements would then be recorded in Table 2: • • • • • Cranial width (CW) Cranial length (CL) Cranial height (CH) Total skull length (SL) Foramen magnum distance to back of skull (FB) These measurements have been made for you and Table 2 has been partially completed for you. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 4 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 5 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 6. Using a calculator, the skull measurements in Table 2, and the formulas below, calculate the Cranial Index (CI) of each skull, the Cranial volume (CV) of each skull, and the Foramen Magnum Index (FMI) of each skull and record your data in Table 2. a. Cranial Index: ?? ?? b. Cranial volume: ∗ 100 1.33∗3.14∗??∗??∗?? 10 c. Foramen Magnum Index: FB SL ∗ 100 7. Using the data in Table 2, answer Question 2 in the Lab Worksheet by graphing the Cranial Volume versus the Foramen Magnum Index for each skull. This should give you a total of five dots on the graph (one dot per skull). Label these dots to indicate which dot corresponds to each skull. 8. Watch the following video about changes that have occurred in hominid skulls over the last several million years from time 0:00 to time 6:01 https://www.youtube.com/watch?v=UCCV96DoTa4&t=184s 9. Based on the Background information, the values you entered in Tables 1 and 2, and the videos you watched, answer Question 3 in the Lab Worksheet. Observations of Developmental and Structural Homology 1. In the laboratory, you would view several animal skeletons and/or drawings of animal skeletons, specifically focusing on the forelimbs/arms. You would compare the animal skeleton forelimbs to each other to determine what bones and structures they had in common and which ones were differently formed in one animal compared to the others. 2. Watch the following video that describes evidence for evolution from time 0:00 to time 10:23. https://www.youtube.com/watch?v=lIEoO5KdPvg&t=495s Note that this video uses the Cetaceans (dolphins, whales, hippopotami, etc.) as an example, but the comparisons between bone structures, embryonic development, and other evidence is done in a similar way to determine the evolutionary relationships among other animals. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 6 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 3. Watch the following video that discusses homologous structures, vestigial structures, developmental embryology, and protein comparisons as evidence for evolution from time 2:36 to time 5:25. https://www.youtube.com/watch?v=O21VOcLIb3M&t=125s 4. Observe the images below that represent the arm bones present in frogs, birds, cats, and humans. Determine which of these bones appear to be organized or shaped similarly (and therefore closely resemble the ancestral condition) and which ones appear to be differently organized or shaped (and therefore differ from the ancestral condition). 5. Based on the videos you watched and your observations from the image above, fill in Table 3 with your observations and answer Question 4 in the Lab Worksheet. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 7 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 6. In the laboratory, you would next view several preserved animal embryos and/or drawings of animal embryos. You would compare the animal embryos to each other to determine what structures they had in common with each other. 7. Observe image of embryos of several different species at a similar stage of development below. 8. Based on the videos you watched and your observations from the figure above, fill in Table 4 by drawing the bird, pig, and human embryos, making sure to label the structures they have in common. Then, answer Questions 5 and 6 in the Lab Worksheet. Natural Selection Simulations in the “White Grasslands” and “Black Forest” habitats • This simulation involves pom poms that can reproduce. These pom poms can be red, black, or white and live in either the Black Forest or the White Grasslands habitat. You and your classmates are the predators of the pom poms and you all have one of three feeding adaptations/structures that resemble a fork, spoon, or a knife. • Pom pom color and predator feeding structures are heritable traits that contribute to survival and fitness of these “organisms”. • There will be three generations of feeding. After each generation the population of hunters will evolve and the population of pom poms will evolve based on who survives each generation round. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 8 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 1. In the Laboratory, to collect data for the Natural Selection simulations, you would perform the following steps: a. To begin, a group of six students would surround the habitat. The Black Forest is represented by a black faux fur mat and the White Grassland is represented by a white faux fur mat. Two students would be given forks, two students would be given spoons, and two students would be given knives. All students would have a soufflé cup that represents their stomach. In the habitat there would be 50 red, 50 black, and 50 white pom poms randomly distributed on the mat. b. The feeding process would begin at the signal of your instructor and would last for 15-20 seconds. Hunters are to lift the prey from the mat and place them into your cup. Cups must remain off the mats. Be competitive hunters, but a pom pom on a fork, spoon, or knife is off limits. c. After the first round of feeding each student “hunter” should count the number of pom poms they had individually “eaten”. The three predators who had “eaten” the most prey would then survive to reproduce, serving as the founders of the second generation. The generation 1 predators will not be represented in the second round of feeding. You would record the total number of predators that survived in Table 5 (for “Black Forest”) or in Table 7 (for “White Grassland”). d. You would next add up the numbers of pom poms that the entire group of predators had “eaten” and record the total number of black, red and white pom poms eaten in Table 5 (for “Black Forest”) or in Table 7 (for “White Grassland”). e. Next, the pom poms that survived Generation 1 would reproduce. To simulate reproduction, you would multiply the number of surviving pom poms of each color by 2, and repopulate the habitat with the number of pom poms you calculated for the next generation. You would record this data in Table 6 (for “Black Forest”) or in Table 8 (for “White Grassland”). f. You would then repeat the feeding process and repopulation for Generations 2 and 3, as described above (repeat steps b-e two more times). You would complete Tables 5 and 6 (for “Black Forest”) or Tables 7 and 8 (for “White Grassland”) based on your results. 9. Watch the following video that shows the process of conducting the natural selection simulation in a “Black Forest” habitat from time 2:03 to time 3:02. https://www.youtube.com/watch?v=3WQrCogLPVI&t=33s BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 9 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas Note that although the entire process of the multi-generation simulation is presented in the video, the video production quality isn’t ideal and it isn’t necessary to watch the entire video (unless you want to) to understand how the simulation process works. 10. Tables 5, 6, 7, and 8 have been completed for you in the Lab Worksheet. 11. Using the data in Tables 7 and 8, answer Questions 7 and 8 in the Lab Worksheet by graphing the starting number of pom-poms of each color for the three generations in both the Black Forest and the White Grassland habitats. Each line graph should have three lines on it, one line for the black “pom-poms”, one line for the red “pom-poms”, and one line for the white “pom-poms” The X-axis of each graph should be the Generation number and the Y-axis should be the “pom-pom” Starting number. 12. Based on the video you watched, and using the data in Tables 5, 6, 7, and 8, answer Questions 9 and 10 in the Lab Worksheet. Hints for question 9: Did the number of “pom-poms” of each color change over time and did certain colors change more than others? Why do you think that would be the case? Was there equal survival among the three types of predators (knife, spoon, fork)? If not, what you do think that would be the case? Hints for question 10: Imagine that instead of having 150 pom-poms to start, there were 1,000 pompoms instead. What would happen if we kept repeating the simulation in the Black Forest habitat for another 25 generations? Imagine that instead of having 150 pom-poms to start, there were 1,000 pompoms instead. What would happen if we kept repeating the simulation in the Black Forest habitat, but from generations 5-15 the Black Forest rapidly changed into a White Grassland? BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 10 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas BIO 101 Lab 10: Human Evolution and Natural Selection Simulations Lab Worksheet Name: _________________________ Section: _______________________ Data Analysis and Synthesis Questions Table 1: Comparative skull analysis data Character A. africanus H. erectus H. neanderthalensis Chimpanzee H. sapiens (Modern) Brow ridges Canine length Forehead Table 2: Quantitative skull analysis data A. africanus H. erectus H. neanderthalensis Chimpanzee H. sapiens (Modern) Cranial width 9 13 15 9 14 Cranial length 13 16 19 11 19 Cranial height 10 10 13 8 14 18 21 22 18 21 5 8 9 4 9 Character Cranial Index Cranial Volume Total skull length Foramen Magnum distance to back of skull Foramen Magnum Index BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 11 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 1. Consider the data obtained and recorded in Table 1. Which sample skull most closely matches the H.sapiens (Modern) skull for how pronounced the brow ridges are, how long the canine teeth are, and how sloped the forehead is? 2. Graph the Cranial Volume versus the FMI for each skull on Graph 1 Graph 1: Foramen Magnum Index versus Cranial Volume for hominid skulls Foramen Magnum Index 50 40 30 20 10 0 0 200 400 600 800 1000 1200 Cranial Volume 1400 1600 1800 2000 3. Based on the data you obtained for the hominid skulls (in Tables 1 and 2 and in Graph 1), describe at least three major changes that have occurred in hominids over the last 2 million years. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 12 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas Table 3. Structural Homology of Vertebrate Forelimbs Animal Bones that closely resemble each other among the animals observed Bones that are differently formed compared to other animals Frog Bird Cat Human 4. Consider how the animals use their forelimbs. Explain the differences between the animal forelimbs relative to each other. In other words, what factors directed the evolution of the different forelimbs? BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 13 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas Table 4. Drawings of Animal Embryos that show Developmental Homology Bird Embryo Pig Embryo Human Embryo 5. What characteristics are shared among all three embryos? 6. Why do the embryos of different species resemble each other? BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 14 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas Table 5: Black Forest Natural Selection Simulation (Predators) Predators Generation Forks Knives Spoons Number 1 Starting number 2 2 2 Number surviving Eliminate the three least 1 0 2 successful feeders 2 3 Generation Number 1 2 3 Starting number # surviving in previous generation multiplied by 2 Number surviving Eliminate the three least successful feeders Starting number # surviving in previous generation multiplied by 2 Number survived at end of Generation 3 Eliminate the bottom three feeders Starting number # remaining in previous generation multiplied by 2 Number eaten Number remaining # at start - # eaten Starting number # remaining in previous generation multiplied by 2 Number eaten Number remaining # at start - # eaten 6 3 2 0 4 6 0 0 3 3 0 0 6 6 0 0 3 3 Table 6: Black Forest Natural Selection Simulation (Prey) Pom Poms Black Red White Starting number Number Eaten Number remaining # at start - # eaten Total Total 50 12 50 34 50 32 150 78 38 16 18 72 76 32 36 144 30 31 36 95 46 1 0 47 92 2 0 92 50 2 0 52 42 2 0 42 BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 15 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas Table 7: White Grassland Natural Selection Simulation (Predators) Predators Generation Forks Knives Spoons Total Number 1 Starting number 2 2 2 6 Number surviving Eliminate the three least 1 0 2 3 successful feeders 2 3 Generation Number 1 2 3 Starting number # surviving in previous generation multiplied by 2 Number surviving Eliminate the three least successful feeders Starting number # surviving in previous generation multiplied by 2 Number survived at end of Generation 3 Eliminate the bottom three feeders 2 0 4 6 0 0 3 3 0 0 6 6 0 0 3 3 Table 8: White Grassland Natural Selection Simulation (Prey) Pom Poms Black Red White Starting number Number Eaten Number remaining # at start - # eaten Starting number # remaining in previous generation multiplied by 2 Number eaten Number remaining # at start - # eaten Starting number # remaining in previous generation multiplied by 2 Number eaten Number remaining # at start - # eaten Total 50 40 50 24 50 18 150 82 10 26 32 68 20 52 64 132 20 46 26 92 0 6 32 40 0 12 64 76 0 12 36 48 0 0 28 28 BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 16 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 7. Create a line graph that illustrates the change in pom pom populations in the Black Forest habitat Be sure to include x-axis and y-axis labels, a key describing each line, and a chart title. You may use the charts below, or you may use Microsoft Excel (or another graphing program) to make the graphs and then attach your graph to your Lab Worksheet. Graph 2. Line Graph of the starting number of pom-poms of each color versus Generation number for the Black Forest environment BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 17 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 8. Create a line graph that illustrates the changes in pom pom populations in the White Grasslands habitat. Be sure to include x-axis and y-axis labels, a key describing each line, and a chart title. You may use the charts below, or you may use Microsoft Excel (or another graphing program) to make the graphs and then attach your graph to your Lab Worksheet. Graph 3. Line Graph of the starting number of pom-poms of each color versus Generation number for the White Grasslands environment BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 18 To submit this assignment, students will complete the Lab Worksheet on pages 11-19, then upload their completed document as a DOC or PDF file in Canvas 9. Answer the following questions by referring to your evidence in Tables 5-8. a. Did evolution by natural selection occur for prey in the Black Forest and White Grassland environments? b. Did evolution by natural selection occur for predators in the Black Forest and White Grassland environments? 10. What do you predict will happen to the population of pom poms in each of the following scenarios: a. If you continued the Black Forest habitat simulation for another 25 generations. b. If as a result of environmental changes (such as decreased rainfall), the Black Forest habitat changed into White Grassland habitat over 10 years of time. BIO 101 Lab 10: Human Evolution and Natural Selection Simulations 19