Dog size gene found, according to reports in ScienceNOW and BBC News 5 Apr 2007. Domestic dogs have the largest variety of body size and shape of any animal. In a search for genes that determine size, an international team of gene researchers studied DNA of Portuguese water dogs, a breed of dog that has a large variation in size within the breed. They found differences in a gene for a growth factor named IGF-1. They then compared the gene in breeds that are consistently small such as Chihuahuas and fox terriers, and those that are large, such as Great Danes and Irish Wolfhounds. All domestic dogs are descended from wolves, which are large. The researchers believe that a mutation in the IGF-1 gene resulted in the appearance of small dogs about 10,000 years ago and human breeding has ensured the “small” version of the gene survived and spread through the domestic dog population.
Editorial Comment: In spite of the large variety in body size and shape, all domestic dogs and wolves are one kind which interbreed with fertile offspring, and show no evidence of evolving into anything else. It is interesting that human intervention is needed to maintain the variety in dogs. If it is just left to “survival of the fittest” these genes are eliminated and species become more uniform, like present day wolves. This is partly because many of the characteristics of modern dog breeds are actually degenerate traits that could not survive without human care. However, it is possible that some of the variety in domestic animals was built in by God and meant to be maintained by humans as part of our mandate to rule the other living things on the earth. (See Genesis 1:28) (Ref. canines, genetics, dominion)
Evidence News 29th August 2007