These puppies are from the same litter, but they look different. Why? The wrinkly puppy probably had a mutation in its gene.
The grey wolf was domesticated 10,000 years, and since it was selectively breeded we now have more than 400 breeds of dogs. Scientists checked the DNA of two different types of dogs and found small differences.
For more information about the genetics of this story, listen to the video of this BBC news story. Also, read the following questions and answers.
What are genes?
Genes are sentences made up of the letters A C G and T.
What are genomes?
Genomes are the instruction set for life. The body is made up of genomes.
What is DNA?
DNA comes in two halves both with the same amount of information.