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110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

Topics Title: “Shark Evolution and Conservation” Evolution, Apex Connections Predators and Conservation Surfers share the water with

Focus Question Grades When did first appear on Earth and why are they important to 6-8 marine ecosystems today?

Duration Objectives/Outcomes 60 minutes Students will be able to:

 Graph the lengths of various large sharks and compare them to Materials Megalodon  Pencil or pen, ruler  Understand how to use a phylogenetic tree  Chromebook  Understand the importance of sharks in a marine ecosystem  Google Sheets  Internet access  Student handouts Key Terms  Apex predator, ecosystem, chondrichthy, food web, conservation, Standards phylogenetic tree NGSS  MS-LS4-2 Outline  MS-ESS3-3  Discuss the Focus Question with class: When“ did sharks first Practices: appear on Earth and why are they important to marine ecosystems  Engaging in Argument today? from Evidence  Analyzing and Inter-  Next show them the video “Why Sharks Matter” (about 4 minutes) preting Data https://www.youtube.com/watch?time_continue=84&v=DvRN3a3j5xQ Crosscutting Concepts:  Students will break into groups of 2 (or some can work alone) to  Cause and Effect work on the student handout and the graph. (You will also have to  Stability and Change provide Students Handout with background information) Core Ideas:  LS4.A: Evidence of Com-  To wrap up the lesson, come back and have students answer the mon Ancestry and Diver- Focus Question one more time and have students brainstorm sity and/or shark what they wrote for the “Reflection” on the handout.  ESS3.C: Human Impacts on Earth Systems Assessment 1. Student engagement and participation.

SHACC has a variety of 2. Completion of worksheet: “SHARK EVOLUTION AND lesson plans that you CONSERVATION” might find fun for you students. Visit https://shacc.org

1 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

Materials GUIDED INSTRUTION:  Pencil or pen, ruler  Chromebook PROCEDURE:  Google Sheets 1. Discuss the Focus Question. Record responses or have students  Internet access write down the question and responses in their notebook  Student handout (Interactive Science Notebook or Logbook). You will come back to EXTENSIONS: this at the end of the lesson and record their thoughtful answers.  Create an Infographic for 2. Have students discuss with their “elbow partners” about what they a favorite shark think of sharks.  Research and create a 3. Have students “popcorn” read and annotate the “Background” PowerPoint presentation on a favorite shark information.  Create a video to help 4. Next show them the video (about 4 minutes) save the sharks https://www.youtube.com/watch?time_continue=84&v=DvRN3a3j5xQ  Watch the documentary “Sharkwater” or (File:Megalodon--Scale-Chart-SVG.svg. (n.d.). Retrieved “Sharkwater Extinction” October 21, 2019, from by Rob Stewart. Here is https://commons.wikimedia.org/wiki/File:Megalodon-Carcharodon- the link to the website Scale-Chart-SVG.svg.) for worksheets and more 5. Students will break into groups of 2 or some can work alone to work background information. on the student handout and the graph. NGSS 6. Students will need to have access to the internet to research the MS-LS4-2: Apply scientific ideas to lengths of the 5 large sharks they choose to compare to construct an explanation for anatomi- Megalodon. Be sure to either use the metric system or standard cal similarities and differences among measurement units. modern organisms and between modern and organisms to infer 7. You will need to set up Google Classroom if you would like students evolutionary relationships to turn in their graphs digitally or have them “share” it with you. MS-ESS3-3: Apply scientific principles You may want to modify this and have them create the graph by to design a method for monitoring and minimizing a human impact on hand. You will need graph paper if you choose to make this modifi- the environment cation. Practices Analyzing and Interpreting Data 8. Students will need to create a new Google Sheets document in Engaging in Argument from Evidence to create a bar graph. Make sure to remind them to title the Core Ideas document with their name and their partner’s name. LS4.A: Evidence of Common Ancestry and Diversity 9. To wrap up the lesson, come back to the Focus Question and have ESS3.C: Human Impacts on Earth Sys- them answer the question. tems Crosscutting Concepts 10. Then have students brainstorm and/or shark what they wrote for Patterns, Cause and Effect, the “Reflection” on the handout. Stability and Change

2 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

RESOURCES: Estes, J. A., Terborgh, J., Brashares, J. S., Power, M. E., Berger, J., Bond, W. J., … Wardle, D. A. (2011). Trophic Downgrading of Planet Earth. Science, 333(6040), 301–306. Retrieved from https://science.sciencemag.org/ content/333/6040/301.full File:Megalodon-Carcharodon-Scale-Chart-SVG.svg. (n.d.). Retrieved October 21, 2019, from https:// commons.wikimedia.org/wiki/File:Megalodon-Carcharodon-Scale-Chart-SVG.svg. Hara, Y., Yamaguchi, K., Onimaru, K., Kadota, M., Koyanagi, M., Keeley, S. D., … Kuraku, S. (2018). Shark ge- nomes provide insights into elasmobranch evolution and the origin of .Nature Ecology & Evolu- tion, 2(11), 1761–1771. doi: 10.1038/s41559-018-0673-5 Long, J. A., Burrow, C. J., Ginter, M., Maisey, J. G., Trinajstic, K. M., Coates, M. I., … Senden, T. J. (2015). Correc- tion: First Shark from the Late (Frasnian) Gogo Formation, Western Australia Sheds New Light on the Development of Tessellated Calcified Cartilage.Plos One, 10(6): e0131502. doi: 10.1371/ journal.pone.0131502 Martinez-Perez, C., Martin-Lazaro, A., Ferron, H. G., Kirstein, M., Donoghue, P. C. J., & Botella, H. (2018). Vas- cular structure of the earliest shark teeth. Acta Geologica Polonica, 68(3), 457–465. Retrieved from https:// geojournals.pgi.gov.pl/agp/article/view/26058 Myers, R. A., Baum, J. K., Shepherd, T. D., Powers, S. P., & Peterson, C. H. (2007). Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean. Science, 315(5820), 1846–1850. doi: 10.1126/ science.1138657 Pimiento, C., Ehret, D. J., Macfadden, B. J., & Hubbell, G. (2010). Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama. PLoS ONE, 5(5): e10552. doi: 10.1371/ journal.pone.0010552 Pimiento, C., & Clements, C. F. (2014). When Did Carcharocles megalodon Become Extinct? A New Analysis of the Fossil Record. PLoS ONE, 9(10): e111086. doi: 10.1371/journal.pone.0111086 Raup, D. M., & Sepkoski, J. J. (1982). Mass Extinctions in the Marine Fossil Record.Science, 215(4539), 1501– 1503. doi: 10.1126/science.215.4539.1501 Stevens, J., Bonfil, R., Dulvy, N. K., & Walker, P. A. (2000). The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems.ICES Journal of Marine Science, 57(3), 476– 494. doi: 10.1006/jmsc.2000.0724 Teen Kids News. (2017, August 31). Why Healthy Oceans Need Sharks? Retrieved October 21, 2019, from https://teenkidsnews.com/tkn-news/science/why-healthy-oceans-need-sharks/. Turner, S., & Miller, R. (2005). New Ideas About Old Sharks. American Scientist, 93(3), 244-252. doi: 10.1511/2005.53.965

3 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

Shark Evolution and Conservation Activity (STUDDENT HANDOUT)

BACKGROUND: Sharks have a cartilaginous skeleton and belong to the phylum. Their ancestors first evolved around 450 million years ago (Hara et al., 2018). According to fossil records, modern cartilaginous fishes, like sharks, derived from jawless fishes or agnathans (Turner & Miller, 2005). Today, there are approximately 830 of Chondrichthyes, which also include skates and rays (Turner & Miller, 2005). Chondrichthyes have survived five mass extinctions (Raup & Sepkoski, 1982). The evolution of jaws enabled fish to grasp live prey and even cut or chew for easier digestion. It is thought that this useful adaptation increased the evolutionary opportunities for early fishes and particularly sharks, thus helping them to survive the harsh marine ecosystem (Turner & Miller, 2005). As jaws evolved so have teeth. Most sharks’ teeth continuously replace themselves throughout their lifetime, leaving behind an abundance of fossil records (Martinez-Perez et al., 2018). Because sharks’ skeletons are made of cartilage there are very few other than teeth for paleontologists to study. Based mostly on an abundance of dental fossil records, Carcharocles megalodon (“Megalodon”) is confirmed to be the largest shark to have ever lived on Earth. According to Megalodon’s tooth height, it reached a total length of about 14.2-16m or about 50 feet (Pimiento et al., 2010). Megalodon was also an apex predator that fed on marine mammals, such as cetaceans (whales and dolphins). It lived on Earth from 15.9-2.6 million years ago (Pimiento & Clements, 2014). Apex predators feed at the top of the food web and usually do not have predators of their own. They are often large-bodied vertebrates with large habitat ranges. These apex predators, such as the Megalodon and today’s large sharks, are important for maintaining stability within an ecosystem. If apex predators disappear, they can produce negative effects throughout the marine food web (Myers et al., 2007). Today, humans are having an impact on apex predators by overfishing and therefore are negatively impacting food webs. This impact of removing apex predators is called “top-down” impacts or “trophic cascades” as trophic pyramids (organized food webs) are altered affecting all aspects of the ecosystem (Estes et al., 2011). Over the past 35 years, 11 large shark populations decreased therefore having extreme effects on the marine ecosystem which they live in, such as the northwest Atlantic ocean ecosystems. Because large sharks prey on rays, skates, and small sharks (elasmobranchs), an abundance of cownose rays in the northwest Atlantic ocean easily destroyed the local scallops in that area (Myers et al., 2007). Examples like this is evidence that sharks are important for a healthy marine ecosystem. Sharks have stood the test of time and survived five major extinctions, but today their populations are declining at an alarming rate and quickly altering marine ecosystems. It is important that research continues to be done on the importance of apex predators and the need to protect them. Internationally, restrictions need to be made and enforced in order to have sustainable and healthy marine ecosystems that will remain balanced for years to come.

4 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

(STUDDENT HANDOUT)

5 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

(STUDDENT HANDOUT)

Figure 1. Phylogenetic Tree. Fossil discoveries in the deep geological record show that the early fishes diversified during the period into several major groups, many of which went extinct by the end of the Devonian (Turner & Miller, 2005).

6 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

Name:______Period:______Date:______

SHARK EVOLUTION AND CONSERVATION

Directions: Using the Background information and the Phylogenetic Tree answer the following questions. Once you have answered the questions, create a graph of your own comparing Megalodon length with 5 other large sharks, such as the , great white, bull shark, , mako shark, goblin shark, greenland shark, and great hammerhead shark. . 1. When did sharks first appear on Earth? ______

2. What group of fish did they evolve from? ______

3. What is the shark’s skeleton made out of? ______

4. When did Megalodon first appear on Earth and when did he go extinct? ______

______

5. How long was Megalodon? ______

6. What is an apex predator? Give an example.______

______

7. Why are apex predators important to an ecosystem?______

______

8. Looking at the phylogenetic tree, when did chondrichthyans (sharks) first appear on Earth?

______

9. When did tetrapods (humans) first appear on Earth? ______

______

10.What fish did tetrapods (humans) evolve from?______

7 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

11. Now that you know the length of Megalodon, research the length of 5 large sharks. (Below is a list to choose from.) Using Google Sheets, create a bar graph comparing the modern day sharks to the prehistoric Megalodon. Don’t forget to give your graph a title, label the x and y axis and create a key. Use Google Classroom to turn in your graph.

Large sharks to choose from, but only choose 5 for your graph:  bull shark  tiger shark  basking shark  whale shark  great white  mako shark  goblin shark  greenland shark  great hammerhead shark  blacktip reef shark 

Using the internet find the lengths of your 5 sharks. Use this data to create your graph.

Reflection: Why are sharks important and what can we do to help save them? ______

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8 110 Calle Iglesia San Clemente, CA 92672 (949) 388-0313 https://shacc.org Lesson Plan

KEY: SHARK EVOLUTION AND CONSERVATION

1. When did sharks first appear on Earth? 450 MILLION YEARS AGO

2. What group of fish did they evolve from? JAWLESS FISH OR HAGFISH

3. What is the shark’s skeleton made out of? CARTILAGE

4. When did Megalodon first appear on Earth and when did he go extinct? FIRST APPEARED 15.9 MYA AND WENT EXTINCT 2.6 MYA

5. How long was Megalodon? ABOUT 14.2-16M OR OVER 50 FEET LONG

6. What is an apex predator? Give an example AN APEX PREDETOR EATS AT THE TOP OF THE FOOD WEB AND DOES NOT USUALLY HAVE PREDATORS

7. Why are apex predators important to an ecosystem? THEY KEEP THE FOOD WEB BALANCED AND THE ECOSYSTEM HEALTHY

8. Looking at the phylogenetic tree, when did chondrichthyans (sharks) first appear on Earth? ABOUT 450 YEARS AGO, AT THE END OF THE ORDOVICIAN PERIOD

9. When did tetrapods (humans) first appear on Earth? ABOUT 400 MYA OR IN THE MIDDLE OF THE DE- VONIAN PERIOD

10. What fish did tetrapods (humans) evolve from? SARCOPTERYGIANS

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