Scientists have hotly debated the ancestral origin of the domesticated dog for years. While it is widely accepted that the modern gray wolf is the ancestor of man's best friend because of genetic likeness, the theory that domesticated dogs descended solely from wolves is up for grabs.

In a recent study, Dr. Vladimir Dinets, an assistant research professor of psychology at the University of Tennessee-Knoxville, contends that dogs, as a species, were not the result of domesticated wolves, as is popularly believed. 

Instead, Dinets declares that dogs derived from two interbred canine species: a small extinct Asian dog and the gray wolf, a primitive hybridization resulting in the birth of wild dogs. However, because this ancient hybrid is most likely extinct, there is no way to compare their genetic makeup to that of modern-day dogs. Dinets believes that these wild dogs existed long before humans began domestication of wolves, the most popular theory of how our furry companions came into being.

"The extinct wild dog was probably closely related to wolves of India and China, but it was a separate species, and so are modern dogs despite having interbred with wolves over the centuries in many parts of the world," Dinets told Nature World News in an interview.

There are a great number of contradicting theories regarding the evolutionary biology of dogs. Most scientists theorize that cavemen domesticated wolves to aid them in hunting; however, the timeline of when that took place is a topic of contention. Recent fossil evidence supported the idea that wolf domestication went as far back as 27,000 years, but other contemporary findings suggest that those fossils were of small wolves and that domestication began less than 10,000 years ago.

The article, published in Vavilov Journal of Genetics and Breeding, quantifies inconsistencies within current canine classifications (there are many different versions) and recommends taxanomic solutions. The genetic similarities between all canid species are high, according to Dinets, which makes organizing the animals all the more baffling.

Recently, scientists have been listing dog as a subspecies of the gray wolf. However, Dinets cites evidence proving this classification is overly simplified.

"The differences between Dog and Gray Wolf are larger than between any domestic animal and its wild ancestor," Dinets states in the study. Modern dogs that have become wild, such as the Australian dingo, do not resemble gray wolves. Even the earliest examples of dog fossils do not mirror the gray wolf, but rather look like existing wild dogs.

"I don't think there's enough difference to separate modern dogs from their ancestors as a new species, but I might be wrong," Dinets said in the interview. "The techniques for studying ancient DNA are improving, so we might find out eventually."

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