1. Show photos of few very different-looking dog breeds, such as a Chihuahua, a Saint Bernard and a Greyhound.
2. Ask students to vote if they think these three dogs came from the same ancestor or different ancestors. After tallying the votes, explain that scientists have figured out that every dog breed in the world today probably came from the same kind of animal. Ask students to guess what animal they think is the ancestor of all dogs. After students have shared their thoughts, explain that based on fossil evidence, scientists have figured out that dogs probably came from the wolf.
3. Show two photos of a wolf – a full body shot and a close-up of its head.
4. Ask students to compare and contrast the wolf’s physical appearance with that of the three dogs you presented earlier. For each dog, write down the similarities and differences between that breed of dog and the wolf. For example, create a chart like the one below and fill it in with your students’ observations.
5. Lead a discussion with the students about the differences that they identified. Brainstorm about some general differences (physical, as well as behavioral) between wild wolves and domestic dogs.
o Physical differences: Dogs generally have smaller skulls, brains, paws and teeth than wolves. The ears of domestic dogs tend to be floppier and their skin tends to be thicker than those of wolves. Dogs, unlike wolves, often have tails which curl upwards. There is a great variety in the size, color, fur, and build between different breeds of dogs, while all wolves are fairly similar in size, build, and appearance.
o Behavioral differences: Dogs are generally tamer, more playful, easier to train and more tolerant of and more attached to humans than wolves. Dogs bark frequently and in many different situations, while wolves, generally, howl or bay less frequently and for shorter periods of time. Dogs, unlike wolves, tend to retain some childlike behaviors (like playfulness) through adulthood.
LEARNING ACTIVITY 1:
2. Ask students how they think a wolf could have evolved into a dog. Discuss answers. Explain that no one knows for sure, but there are several theories about how this happened. Explain that you are now about to show them a video segment that presents different views of how dogs transformed into wolves. Provide them with a FOCUS FOR MEDIA INTERACTION, asking them to listen for and write down two theories about what led to this transformation.
3. PLAY Video Segment 1, “From Wolf to Dog.” After the segment, ask your students to discuss the theories that were discussed during the clip. (Theory 1: Humans adopted wolves and caused them to become dogs. Theory 2, proposed by Dr. Raymond Coppinger: Wolves with short “flight distances” were successful at scavenging at garbage dumps. [Flight distance describes how close an animal will allow a potential threat to get to it before it flees and how far away it will run.] The wolves with the shortest “flight distance” survived and transformed into dogs.) Help students brainstorm what human “garbage” might have looked like 14,000 or 15,000 years ago. It probably contained tossed away bones with scraps of meat on them…something very tempting to a hungry wolf.
4. Ask students what they think of each theory. (Possible answers: The theory of human wolf adoption leading to the evolution of the wolf into the dog might be implausible because, according to Dr. Coppinger in the video segment, if people were to adopt wolves they would need to do so within 13 days of the wolf’s birth and would have to spend a lot of time bottle-feeding the wolf puppies, which might not have been realistic in the Stone Age/Mesolithic times.)
5. Ask students how long they think it might have taken for wolves to evolve into dogs. Discuss their responses.
6. Explain that you are about to show them a clip that discusses how quickly this transition might have occurred. Provide them with a FOCUS FOR MEDIA INTERACTION, asking them to watch the video segment to find out how long it might have taken for wolves to evolve into dogs.
7. PLAY Video Segment 2, “The Speed of Change.” After students have viewed the segment, ask them how long they think it took for wolves to evolve into dogs? (Possible answer: Transformation might have happened very quickly-”in the blink of an evolutionary eye.”) How does the experiment conducted by Dmitri Belyaev in Siberia provide us with information about the speed of transition from wolf to dog? (Possible answers: By selecting foxes for the quality of tameness alone, in just 10 years, physical and behavioral differences were apparent. The foxes became more dog-like. This experiment shows that changes can take place in a relatively short amount of time.)
LEARNING ACTIVITY 2:
1. Ask students to guess how many breeds of dogs they think there are today.
2. Explain that you are now going to show them a short video segment about different types of dogs that exist today. Provide them with a FOCUS FOR MEDIA INTERACTION, by asking them to watch the segment to find out how many internationally-recognized breeds there are today.
3. Play Video Segment 3, “Today’s Dog.” After students have viewed the segment, ask them how many internationally-recognized dog breeds exist today. (More than 400.) Explain that some of the differences between dogs are due to natural selection. For example, dogs with a thicker fur might survive better in a colder climate than those with no fur or thin fur. Much of the variation that is seen between dog breeds today, however, is the result of human breeding of dogs, based on hair color, size, personality traits, etc.
4. Distribute the “Dog Breed” student organizer to each student. Divide students into small groups and assign each group to a specific group of dogs: sporting, hound, working, terrier, toy, non-sporting or herding. It is fine if multiple groups of students are assigned to the same dog group.
5. Ask each student group to select one dog breed from its assigned dog group. Ask the students to complete the student organizer with information about that breed and to include a drawing or image of that dog. Encourage students to go to the American Kennel Club Web site at http://www.akc.org/breeds and search for their assigned group by clicking on “breeds by group” on the left navigation bar.
6. Ask students to share information about their groups and specific breeds with the rest of the class.
Here is some information (from the American Kennel Club Web site), which you can share with your students:
Description of Group
|Sporting||Active, alert and likeable dogs. Very good in water and in the woods. Need regular, invigorating exercise.||Pointers, Retrievers (Golden Retrievers, Labrador Retrievers, etc.), Setters (Irish Setters, etc.) and Spaniels (cocker spaniels, etc).|
|Hound||Good hunters. Can follow a trail with their very strong senses of smell.||Include Bloodhounds, Basset Hounds, Beagles, Greyhounds, Saluki and others.|
|Working||Can perform important functions for humans, such as protecting property, saving people in water and pulling sleds.||Include Doberman Pinschers, Great Danes, Siberian Huskies, Rottweilers and others.|
|Terrier||Feisty, energetic dogs who often, have little tolerance for other animals (including other dogs). Their ancestors hunted and killed vermin.||Include Terriers (Bull Terriers, Irish Terriers, Scottish Terriers, etc.) and Miniature Schnauzers.|
|Toy||Small in size. Varied personalities and appearances.||Chihuahuas, Maltese, Pugs, Shih Tzus, Yorkshire Terriers, etc.|
|Non sporting||Sturdy animals with a wide range of shapes, sizes and personalities.||Dogs include Bulldogs, Chow Chows, Dalmatians, Lhasa Apsos and Poodles.|
|Herding||Can control movement of other animals and get them to move from one point to another.||Australian Cattle Dogs, Border Collies, Corgis, Sheep Dogs and Shepherd Dogs (Belgian Sheepdogs, German Shepherds Dog, Old English Sheepdogs, etc.)|
7. Punch holes in the pages and place them in a binder to create a dog breeds book for your class. Note: Encourage students to add more pages to this book in the coming days and weeks, as they discover more about different types of dogs.
8. Encourage students to add fun facts to the dog book. For example, the smallest mature dog was a Yorkshire Terrier that was 2 1/2 inches high at its shoulder. The tallest dog ever was a Great Dane who stood 41 inches (3 ft, 5 inches) high.
CULMINATING ACTIVITY: Tails and Tales: A Dog Story
1. Distribute the “Dog Interview” Student Organizer to each student. The students (working alone or in small groups) will interview a dog owner, using the student organizer as a guide. The interview should be used to gather as much information about the dog as possible. The students may also want to include photographs, video footage and/or drawings of the dog, as well as other items, which could help provide a vivid description of this dog’s temperament, history, and personality. (If a student has a dog at home, ask him/ her to interview someone else who has a dog.)
2. Encourage students to do some research on the particular breed(s) of their interviewed dog after the interview. Ask them to think about whether the dog they are researching seems to “fit in” with the breed’s temperament, ability, etc. If the dog’s breed(s) are unknown, ask students to try to guess its breed(s) by conducting research about the characteristics of different breeds. Students should provide the reasoning behind their guesses.
3. The students should summarize their research by creating a poster about the dog and/or giving a 5-10 minute presentation about this dog to the class, featuring the material gathered (including any audiovisual materials).