Just Like Human Siblings
Looking around your own family you can probably see plenty of variation even among those most closely related to you such as your parents and/or siblings. It’s no different with dogs. Genetic Recombination is when chromosomes swap various pieces of DNA between them, resulting in the inheritance of a unique combination of DNA. This process happens in the passing down of genes from the parents, grandparents, and even great grandparents. On average, through the DNA of their parents, puppies are receiving about 25% of their total genetic makeup from each of their grandparents and approximately 12.5% from the great grandparents. Because of the random nature in which genes are passed down, siblings can sometimes have differences in the breeds identified (or placement of the breeds) in their family trees. The puppies here are a great example as they are all from the same mother. The black one on the left and the black and white one on the right have the same father. And yet, just like human siblings, they all have a unique look based on what they individually inherited from mom and dad.