DNA Holds Answers Why Dogs Vary In Size More Than Any Other Mammal
Genetics researchers at the University Of Utah have studied why dogs vary more in size than any other mammal, and it was found that in a snippet of canine DNA that regulates growth to keep small dogs from ever growing large was found to be present.
This DNA snippet is a form of a regulatory sequence that controls a growth inducing protein hormone that is the same as what regulates the growth from birth to adolesence of all creatures, both human and animal, and keeps small breeds small, and big breeds large among canines. Large dogs are missing this regulatory sequence of DNA, which explains their much larger size.
All dogs under 20 pounds have this DNA snippet according to the research from the University Of Utah. DNA from 3,241 breeds were examined in the study. Strangely, the Rottweiler breed appears to have this growth inhibiting DNA sequence, yet some other factors seem to prevent it regulating the growth of these large dogs.