You can learn more about dogs and recent research on their origins and behavior at www.pbs.org/wgbh/nova/dogs/ (PBS). A teacher's guide for the Nova program "Dogs and More Dogs" can be found at www.pbs.org/wgbh/nova/teachers/programs/3103_dogs.html (PBS).

You can check out the 50 most popular dog breeds in the United States at www.enchantedlearning.com/subjects/mammals/dog/popular.shtml (Enchanted Learning).

Information about dog genome projects can be found at mendel.berkeley.edu/dog.html (University of California, Berkeley), www.fhcrc.org/science/dog_genome/ (Fred Hutchinson Cancer Research Center), www.broad.mit.edu/media/2003/pr_03_tasha.html (Broad Institute), www.ncsu.edu/news/press_releases/03_08/215.htm (North Carolina State University), and www.genomenewsnetwork.org/articles/11_01/Dog_feature1.shtml (Genome News Network).

Sohn, Emily. 2003. Figuring out what makes dogs tick. Science News for Kids (Oct. 1). Available at http://www.sciencenewsforkids.org/articles/20031001/Note3.asp .

Books recommended by SearchIt!Science:

Dogs: The Wolf Within — Dorothy Hinshaw Patent Published by Carolrhoda Books/Lerner Publishing, 1992. Why does your dog bury its bones? Why does it stop at every tree (or fire hydrant)? And what makes dogs so friendly to people? The answers have to do with its wild relative, the wolf. Around 12,000 years ago, prehistoric people began taming wolves. Dogs today are related to those wolves and still carry some of the behaviors of their ancestors. With color photographs, this book looks at what today's wolves and dogs have in common. The ways they eat, hunt, develop packs, mate and raise their young, and protect each other are all considered. The various breeds and behaviors of domesticated dogs, from the loose-skinned shar-pei to the fast-footed husky, are explored. The book discusses how dogs have become part of the human world, both as companions and as helpmates, and the future of wild wolves.

How Dogs Came From Wolves: And Other Explorations of Science in Action — Jack Myers Published by Boyds Mills Press, 2001. How did dogs come from wolves? Can elephants talk? Do dogs see in color? How do birds hatch eggs? Explore 12 scientific questions and then witness the scientific experiment or study that was created to solve each mystery.

My Pet Dog — Ruth Berman Published by Lerner Publishing, 2001. You really want a dog. For your birthday, your parents give you a gift certificate for a puppy. That’s the easy part. Listen to a girl who researches different information to decide which dog is best for her family. Investigate what kind of food, equipment, training, and healthcare puppies and dogs need. See what happens when Cinder comes home. The first few weeks were difficult—especially at night. Learn about the responsibility that comes when you introduce a new puppy into your family.

chromosome A tiny, thread-like structure in each cell of a living thing. Chromosomes carry the genes that pass on hereditary traits, such as eye color or the color of an animal's coat, from parents to offspring.

DNA Short for deoxyribonucleic acid. The material that makes up the genes and that is found in all cells. DNA controls the function of all the cells in the body. DNA in the body consists of two thread-like strands that are linked together in the shape of a double helix.

A strand of DNA is shaped like a twisted ladder. The rungs of the "ladder" are made of four different bases.

Carlyn Iverson/The American Heritage® Children's Science Dictionary

gene A tiny part of a chromosome, made up of molecules of DNA. Traits are passed from parent to offspring through the genes. The shape of a plant leaf, the color of an animal's coat, and the texture of a person's hair are all determined by genes.

genome All the genes that are contained in the chromosomes of a living thing.

Copyright © 2002, 2003 Houghton-Mifflin Company. All rights reserved. Used with permission.