Dogs Dogs and more Dogs video hadnout PDF

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SBI 3U Biology Name ___________________ Video on Artificial Selection Date __________

Period ____

NOVA: Dogs, Dogs and More Dogs

Whether you are a dog person or not, there’s no denying that thanks to human intervention they are one of the most diverse species on earth. With an amazing array of sizes, shapes, colors, temperaments and other quirks, canis familiaris features one of the most tinkered-with gene pools in the animal kingdom. 1. Dogs come in more shapes and sizes than any other mammal on the planet. 2. All dogs arose from a population of fairly homogenous wolves about (1,000) (10,000) (100,000) (Circle one) years ago. 3. The program relates two competing hypothesis’s about how dogs were domesticated. As you watch, take notes on the two explanations for the evolution of dogs. The adoption hypothesis

The adaptation hypothesis.

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Ancestors are said to do a similar thing to what we do: they adopt/find a wolf pup and raise it. Later, the pup might grow into unpredictable and dangerous adults, or run away. As said by James Serpell, “We have to picture maybe thousands of these pet wolves going through this process and sooner or later when you do this with thousands, you're going to get some which grow up to be more amenable to living in that context and less of a threat.”

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Dogs were pre-adapted to living in fairly complicated social groups. Wolf society typically has quite well-established dominance hierarchies within it. Individuals learn to slot themselves into that hierarchy and function within that context.

Which hypothesis do you support? Why? I support the adoption hypothesis because to me, it seems reasonable of how wolves evolved into dogs.

4. What surprising thing happened to the Russian population of foxes as they were breed over 10 generations? They started to have non fox-like characteristics. As mentioned, their ears started down, tails started up, and they started to bark.

5. Why do dogs have tails that stick up, droopy ears, and other traits that are not found in the wolf gene pool? As demonstrated by Belyaev, he bred his foxes for tameness and over the generations their bodies began producing different levels of a whole range of hormones. These hormones, in turn, set off a cascade of changes that somehow triggered a surprising degree of genetic variation.

6. i) True or False: The Saluki dog can outrun any mammal on earth in a 3 mile race. True ii) What are some of the adaptations salukis have which make them excellent “running machines”?

7. True or False: ALL DNA in cells code for proteins. True 8. True or False: A gene can be turned “on” or “off”. True 9. How many different breeds of dogs exist? 400 10. Explain how inbreeding dogs for “perfect” traits also produces “disease” traits as well. As this applies to dogs, it also applies to most other mammals. They are not supposed to breed with family members. This can cause various “diseases” and traits in the offspring/future generations. Inbreeding is the only way to control what the next generation will look like....