Sharks

Project Description:

Our shark unit begins with a lesson on shark anatomy in which the students get a hands-on look at each shark organ by dissecting baby dogfish. Once the students get a grasp of the anatomy of the shark than they can compare modern sharks to extinct sharks by looking at their fossils. This is done through the fossil project which has the teacher burying fossils and having the students dig them up and classifying them. By studying fossils and the modern anatomy of sharks, the students will also learn about the evolution of sharks and that plays a role in speciation. The final part of our shark unit is concentrated on conservation and the ecosystem. Students will learn about different habitats and interactions that different organisms have with one another. Students will address various problems in the environment to get further insight on how the food web works and discover the importance of conservation. Another important topic that will be covered in conservation part of the unit is biodiversity which includes the loss of species, the loss of individual populations within a species, and the loss of genetic variation. By looking human activity and environmental problems students will see that as the biodiversity decreases so does the number of species which ultimately decreases most populations. With a loss in populations comes a loss in genetic variation which can be detrimental in the long run. To tie all of these features of conservation together, the students will be given different problems in the environment and determine what the problem is, construct the food web of their specific animal to understand the interactions they have with other organisms/plants, determine how this problem affects us, and find the solution to the problem. To concentrate more on the conservation side, students will be given another project where they will get a total hands-on experience by playing the role of the conservationist. This project starts out with a guest speaker who is an actual researcher/conservationist which will explain the conservation efforts of a particular organism/plant in their area. The students will then be the conservationist and try to come up with a plausible solution or to spread awareness in the community. To make the students more interested, we will take them on a field trip to a conservation site in their area to familiarize them with the specific organism/plant. The students will do research and attend town meetings to make the community aware of the current situation at hand and hope that they too will join in the conservation movement.

Driving Question:
What have made sharks so successful?

Overall Goals of the Project:

Our goal is to show the students how they can become involved in the conservation effort and to increase their awareness and interest.  Another goal is for the students to understand the evolution and speciation of sharks.  By learning about how each species of shark has adapted to its specific niche, the students will see how each different organism plays an important role in the world’s food web.  With their curiosity piqued, students will be more likely to enter universities focusing on science and also will become more educated voters. 

Project Objectives:

Students will be able to:

• Identify the differences between the species of sharks
• List the many different reasons and methods of classifying organisms
• Identify major organs in a shark and their functions
• Discover what adaptations sharks have to survive in the ocean
• Exhibit that they understand that natural selection does not mean “the bigger the better”
• Talk about the two types of extinction and why a species is likely to go extinct
• How humans have brought on the 6^th major extinction
• Recognize that diversity in a population is essential for that population to stay alive
• Use reasoning and scientific knowledge to predict the species of animal fossils they find in the "field."
• Explain what a fossil is and be able to recognize the different types of fossils.
• Recognize that the fossil record is incomplete because of the strict          conditions that promote fossilization.
• Discuss the theory of evolution and the evidence for evolution and then decide whether they believe in the theory. 
• Observe the evolution of sharks through pictures and then identify specific species that were particularly interesting to them
• Define food chain, food web, producers, consumers
• Work in groups to create presentations
• Identify what factors affect the food chain and think critically about how to manipulate the food chain
• Explain the importance of diversity of species

Rational:

            Over the past 100 years, there has been an exponential increase in
endangered species due to human enterprises.  This has lead to a drastic
decrease in biodiversity, which negatively impacts many habitats throughout the world.  Eric Chivian, the director of the Center of Health and the Global Environment spoke at the COHAB 2005 conference and said, “Do not underestimate me when I say that we are in deep, deep trouble.”

            Biodiversity encompasses genetic diversity, species diversity, and ecosystem
diversity. The increasing loss of biodiversity includes the loss of species,
the loss of individual populations within a species, and the loss of genetic
variation within a species or population which leads to consequential loss of
ecological processes. With these various losses comes a reduction of
biodiversity and benefits to human kind.  For example, as of today “most of our medicine (from common drugs to possible cures for cancers) come from plants, many of which are now endangered.” (Anup Shah)  This illustrates how human exploitation of natural resources could negatively impact humans in the long run, overriding the short-term benefits.

            This project will give students background information on evolution and speciation, and then let them apply this knowledge to the issue of conservation.  By learning about how each species of shark has adapted to its specific niche, the students will see how each different organism plays an important role in the world’s food web.  With their curiosity piqued, students will be more likely to enter universities focusing on science and also will become more educated voters. 

            Currently in the classroom students are learning about these topics, but not applying their knowledge to the area of conservation.  This is a major issue affecting the world right now, and if it is not addressed there could be drastic consequences.  Students will be introduced to the project with a guest speaker on conservation.  They will then be allowed to play the role of conservationist themselves and realize how things that they do can make a positive or negative affect on their community.

Background Information:

            1) Classification and Dissection:

Aristotle was the first to classify animals together with similar characteristics.  He divided animals into two types: those with blood and those without blood, which roughly is the same as our vertebrates and invertebrates.  To unify the naming of organisms and to communicate more efficiently about the increasing number of species being discovered, scholars in the Middle Ages (around the 5th century to the 15th century) translated the common names of organisms into Latin, which was the language of educated persons. These names were often long, and included numerous descriptive terms.  Carl Linneaus classified species in order to create standard names, which were universal and allows us to communicate in a common language.  It was a way to link the name to the object.  Carl Linneaus also created the system that we use today of binomial nomenclature.  This is the genus and species part of classifying an object.  The genus is broader, and is capitalized.  Both are either underlined or italicized.  Linneaus created this system in 1752.  When On the Origin of Species in 1859 by Charles Darwin, the purpose of classification took on a new meaning. Darwin argued that species should be related based on their shared ancestry. He defined species as groups that have diverged from a shared ancestry in recent history, while organisms in higher taxa, such as genus, class, or order, diverged from a shared ancestor further back in history.  By the 19th century, scientists had identified a wide variety of microscopic organisms that did not easily fit into the plant or animal classification system.  Ernst Haeckel proposed placing these unicellular species in a third kingdom, the Protista.  Since then, there have been as many as eight kingdoms.  There are currently three domains, which is broader than a kingdom, which are based on the ribosomal RNA of each organism.  Carl Woese discovered this and created the modern kingdoms of Bacteria, Archaea, and Eucarya. 

The Dogfish shark is a good example of a primitive, jawed fish which is often used for dissection purposes.  They are small sharks, ranging in size from one-half meter to one meter in length.  A variety of websites are online which can provide detailed pictures of step-by-step dissections including http://www.zoology.ubc.ca/courses/bio204/lab3_frameset.htm. 

            2) Natural Selection Lesson:

         In order for other teachers to be able to teach this lesson well by themselves, I would recommend that they visit the website below and read the textbook entitled Geology by: Leon E. Long. This book helped me to create the mini lectures on the types of extinction, and it gave an in-depth explanation and timeline about when and how the first 5 major extinctions occurred, which types of animals went extinct in each one, and which animals where then able to thrive in the absence of the extinct animals. 

         The Bagheera website (http://www.bagheera.com ) has information about endangered species and extinction and gives many examples of animals that are now facing extinction cue to humans. The URL address above will take you to the main page and then click on “into the wild” and then select classroom activities. This will help you to understand why the 6^th mass extinction that is taking place right now is so important to understand, and why we need to take the steps necessary to stop what we have begun.

                      Lastly I used my personal lecture notes from my BIO 213 course

with Professor Levin at the University of Texas at Austin. I realize that these notes are not available to the general public, however most of the lectures he gave us are outlined with main points, graphs and some pictures and he posts them on his class website (http://www.micro.utexas.edu/courses/levin/bio304/). This web site will help in understanding why some animals are more prone to extinction than others, and it explains niches in an easily understood way.

            3) Evolution and Fossil Record of Sharks:

         While writing this lesson plan I found that the resource that I used most often was the Elasmo Research website (http://www.elasmo-research.org/index.html). This website has all you will ever want to know about sharks. It has a well designed site that lets you pick what you want to learn about. Examples of some of it’s’ contents include evolution of specific shark traits, such as the “hammer” on hammerhead sharks; it discusses their behavior, their habitats, and the diversity of sharks in the world. This website also has great illustrations of anatomy and of shark species (even some that have gone extinct.) Lastly this website includes links to many articles in scientific journals that have been published that deal with sharks.

         The textbook I mentioned above, Geology by: Leon E. Long contains great information about fossils. It goes over the optimal conditions for fossilization and it walks you through all of the things you can learn from a fossil. Lastly I also used my BIO 213 lecture notes while writing this lecture which can be found at (http://www.micro.utexas.edu/courses/levin/bio304/). The notes had useful information about evolution in all species as well as the history of Darwin’s theory of evolution, why it has been critiqued and how it has answered these critiques to stand the test of time.

            4) Biomes:

Biomes are defined as "the world's major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment.” There are five biomes in the world: aquatic, desert, forest, grassland, and tundra. Each is then subdivided into smaller categories which make up different habitats for all of the various organisms on Earth. (http://www.ucmp.berkeley.edu/glossary/gloss5/biome/)

            5) Food Web/Chain:

All living things depend on each other to live. The food chain shows how some animals eat other animals to survive. While being food for animals higher in the food chain, these animals may eat other animals or plants to survive. The food chain is a complex balance of life. If one animals source of food disappears, such as from over fishing or hunting, many other animals in the food chain are impacted and may die. Also multiple food chains form a food web because no organism feeds on only one nutrimental source and can obtain their required energy somewhere else.

(http://www.kidport.com/RefLib/Science/FoodChain/FoodChain.htm )

Standards Addressed: 

TEKS:

(1)  Scientific processes. The student conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to:

(A)  Demonstrate safe practices during field and laboratory investigations;

(2)  Scientific processes. The student uses scientific inquiry methods during field and laboratory investigations. The student is expected to:

(A)  Plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting and using equipment and technology;

(B)  Collect data by observing and measuring;

(C)  Analyze and interpret information to construct reasonable explanations from direct and indirect evidence;

(D)  Communicate valid conclusions

3)  Scientific processes. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to:

(A)  Analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information

(4)  Scientific processes. The student knows how to use a variety of tools and methods to conduct science inquiry. The student is expected to:

(A)  collect, analyze, and record information using tools including beakers, Petri dishes, meter sticks, graduated cylinders, weather instruments, timing devices, hot plates, test tubes, safety goggles, spring scales, magnets, balances, microscopes, telescopes, thermometers, calculators, field equipment, compasses, computers, and computer probes

§112.43. Biology,

(9)  Science concepts. The student knows metabolic processes and energy transfers that occur in living organisms. The student is expected to:

(D)  analyze the flow of matter and energy through different trophic levels and between organisms and the physical environment.

Overall Assessments:

Our overall assessments include the unit test and a conservation project, which includes a trip and a presentation. The breakdown of points awarded for the assessments will be as followed:

                        Unit test on Ecology:                             25%

                        Conservation Project Presentation:        20%

                        Natural Selection Project:                     20%

                        Dissection of Dogfish Lab:                    15%

                        Homework and Daily Assignments:       20%

 The Ecology test will be graded as all other unit tests and the students will need to demonstrate sufficient knowledge in all the areas of Ecology discussed in class.  We will be able to assess the completion of the goals of the conservation unit by seeing the students' interest in the conservation project and the field trip, and witnessing their understanding of the conservation effort when they present it to members of the local city council. The Dogfish dissection lab will be assessed on the thoroughness of the lab report that the students will turn in, and class participation during the dissection. The Project on Natural Selection will partially be graded when the students present their animals to the class (if they demonstrate sufficient knowledge of why they have created their animal in a certain way). Later when the game of evolution is played the students will be expected to demonstrate understanding of why their animal did or did not survive the game. Lastly, twenty percent of the students’ grade will be homework and daily assignments. Some of these activities may be graded on a completion basis and other items will be graded on a numerical scale. All of these grades will be returned promptly to the students and if there is a question raised on the grading of any assignment, the student may turn it back in for a re- grading process.