Artificial Selection • Humans have modified species over many generations by selecting and breeding individuals with desired traits • Also called selective breeding • Ex: plants
Artificial Selection: Dog Breeds • All dogs belong to the species Canisfamiliaris • ~400 different breeds • A breed is a subspecies • Recognized breeds are a result of many generations of selective breeding • Video
How to Get an American Foxhound and Why • 400 years ago there was no such thing as a foxhound • How did they get here?
The American Foxhound is half descended from the English Foxhounds that were brought to America in 1650. The English hounds were crossed with a French hound that George Washington received as a gift from Lafayette. The combination breed became an excellent hunter of wild animals. The American Foxhound has great speed and an excellent sense of smell. It can run at high speed for long periods and has a musical bay that is easy to follow. American Foxhounds are still used as hunting dogs today but are also used as companions and watchdogs. English foxhound American foxhound
What features or abilities of dogs are ones humans might breed for? Remember, all dogs are the same species so interbreeding them is possible!
Dog Breeding Example • You want a dog that can hear a polar bear approaching and alarm the bear so that it will turn back. • Which of the following dogs would you selectively breed to produce offspring that would be most effective in scaring away a polar bear? • Why?
Dog Traits • Physical traits serve a very specific function for dogs • Each of these could play an important role, or have significance for humans when they need a dog to perform a particular function
Artificial Selection Requirements • Variation • Differences among individuals • Inheritance • Trait passable from parents to offspring • Selection • Individuals with favorable traits are bred in hopes that those traits will be pass on to next generation • Time • Getting the desired outcome usually requires many generations