Elementary School Science

Input:
What is the most important content in this lesson?
To reach this lesson’s objective, students need to understand:

• The definition of “population” in reference to ecology.

• Animals that have a large population and animals that have a small population.

• The term “endangered” and which animals are “endangered species”.

• The term “extinct” and which animals have become “extinct”.

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How will the learning of this content be facilitated?

• The teacher will begin the class by going to the website World Population Clock (Source: http://www.worldometers.info/world-population/). The website shows the number of births and deaths in the world at the current time as well as the population growth. The teacher should begin a discussion about the figures and explain that the world’s population is growing. The discussion should transition into animal populations.

• The teacher should hand out the worksheet “What is a Population?” If it is possible, project the “What is a Population?” worksheet onto the board using a projector or put into a PowerPoint document and project. As the teacher explains, the students will fill in the blank spaces on their worksheet.

**The student worksheet does not contain all this information. Use this as a guide to explain populations more in-depth to the students**

• In ecology/biology, “population” refers to a group of individual organisms that belong to the same species and live in the same area (geographical). For example, in the ocean you have a population of fish; in the rainforest, you have a population of monkeys.

• Even though organisms may belong to a certain population, there are differences— much like the human population where you have differences in skin color, hair color, and genetic makeup. Not all monkeys are black, gray, and white (like lemurs) or are large in size (like gorillas). However, these organisms can live in the same area and are grouped together as a population.

• When talking about the “geographical area”, the actual size of the area depends on the scientist studying it. For example, a scientist can study one small area of the Swiss Alps or the entire Swiss Alps; a scientist can study one island of Hawaii or all the islands of Hawaii.

• Organisms of a population interact with each other.

• On the ecological hierarchy, population is the second level.

• While communities focus mainly on the area or region, population focuses mainly on the type of organism.

**It is important to stress the difference between population and species. Many students might think that all cats or all dogs, regardless of their location, make up a population. All the dogs or cats in the world make up a “species”. All the dogs or cats that live in one defined region make up a “population”**

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Information Sources:

http://eschooltoday.com/ecosystems/levels-of-organisation-in-an-ecosystem.html

https://www.khanacademy.org/science/biology/ecology/intro-to-ecology/a/ecological-levels-from-individuals-to-ecosystems 

https://www.reference.com/science/five-levels-ecological-organization-266f7baea300bbc

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• After the teacher explains the worksheet, he/she should show the video “Dinosaur” (Source: https://www.youtube.com/watch?v=D8Fp-NvvITw). The video is about 3 minutes long and talks about the different types of dinosaurs and how some birds have evolved from dinosaurs. After the video, the teacher should start a discussion about the content/ what the students observed. The discussion should transition into explaining “extinct” and “endangered” species. The teacher should hand out the worksheet “Extinct & Endangered Species”. If it is possible, project the “Extinct & Endangered Species” worksheet onto the board using a projector or put into a PowerPoint document and project. As the teacher explains, the students will fill in the blank spaces on their worksheet.

**The student worksheet does not contain all this information. Use this as a guide to explain extinct and endangered species more in-depth to the students**

• When a species dies off—meaning that there is no more left on Earth—the species becomes extinct. Think about dinosaurs—dinosaurs no longer exist so they are classified as extinct.

• When a species begins to loose a large number of their population, they are classified as endangered.

• “Extinct in the Wild” means that the species can no longer be found roaming around in the wild, but can, however, be found in captivity (zoos, sanctuaries).

• Extinction of animals occurs for many reasons. The main reason, however, is human influence. Deforestation to build homes or other buildings can result in certain species losing their habitat.

• Natural Forces: climate, weather change, competition between species, decrease in food supply have all contributed to animals becoming extinct. With the case of the dinosaurs, it has been theorized that a large meteorite hit the Earth, which resulted in the death of all the dinosaurs.

• Human Interaction: humans interfering with the natural habitat of an animal can lead to extinction.

• Hunting: hunting, which is a common sport/hobby, has resulted in the endangerment of many animals. For example, in the United States there was such a large population of Canadian Geese that people were encouraged to hunt them. This has stopped, however, because there is a risk of the Canadian Geese becoming an endangered species. Another example is the American Bison. Prior to the arrival of European to the Great Plains, there was a large population of American Bison. Europeans began hunting the bison and the population began to decrease. Thankfully, the American Bison became a “protected species” and has been removed from the endangered species list.

  • Animal Body Parts/ Products: these products include fur, skin, horns, and feathers. Animals are not only hunted for food, but for the products they produce. Minks, foxes, and rabbits are hunted for their fur to make coats, rugs, and other products. The African Elephant was hunted for their ivory tusks. Due to the large number of hunters, the African Elephant has become endangered and is a protected species. Tigers in China are another example. In Chinese medicine, tiger bones are commonly used.

  • Loss of Habitat: when an animal loses its habitat, they are at risk for becoming endangered. Human interaction, such as deforestation, can cause animals to die off. Natural disasters, such as hurricanes and earthquakes, can also result in the loss of habitat.

  • Pollution: pollution not only affects humans, but animals as well. Contaminated water can cause animals to die off. If one species dies off, it can interfere with the food chain resulting in more species dying off.

  • New Species to a Habitat: if a new species is introduced to a habitat, it can become dominate and kill off the other species.

• If a species is “endangered”, it is classified into one of three groups:

  • Critically Endangered

  • Endangered

  • Vulnerable

• In many countries, there are laws protecting these animals. Poaching is the act of hunting or killing game (animals) illegally. In the sense of “illegally” it can be anything from hunting/ fishing without a license to hunting endangered species.

• Amphibians can be extinct and/or endangered species as well.

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Information Source:

http://www.ducksters.com/animals/endangered_animals.php

http://www.ducksters.com/animals/how_animals_become_extinct.php

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• The last worksheet that should be reviewed is “The Top Organisms of the World” information sheet. This information sheet lists the largest number/ population of organisms in the world. The teacher should review the information sheet with the students and discuss their observations.

**Refer to the student copy**

 

Information Source:

http://www.npr.org/sections/thetwo-way/2011/11/03/141946751/along-with-humans-who-else-is-in-the-7-billion-club

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• After the worksheet is completed, the students will participate in an activity called “Endangered or Extinct?” The students will work in groups of three. Each student will get an “Endangered or Extinct?” worksheet. On desks around the room will be pictures and names of different animals. The students will go around to each desk, look at the pictures, and determine if the animal is extinct of endangered and fill in their worksheet. Allow the students to work for about 10-15 minutes. Reconvene and discuss when the students are finished.

• Answers

• Endangered

• Forest Elephant

• Marine Iguana

• Polar Bear

• Tree Kangaroo

• Giant Panda

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• Extinct

  • Dodo

  • Passenger Pigeon

  • Great Auk

  • Tasmanian Tiger

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• The final assessment will be for the students to answer the question:

Think about what you learned in class today. Define the word “population” in reference to organisms. What is the difference between “species” and “population”? What is the difference between “endangered” and “extinct”? What are some reasons for extinction? What are some possible solutions?