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Name: Helena
Status: Other
Grade:  Other
Location: N/A
Country: United States
Date: August 2005


Question:
What are the latest news about dogs origins using nuclear DNA...can we prove that the wolf is the only ancestor?



Replies:
Hi Helena!

What a pleasure answering a question from my country! Because i am brazilian and live in Brasil. Even a am not a biologist or so i looked into Internet and found an interesting paper from SCIENCE, VOL. 276 13 JUNE 1997 dealing exactly with your question. Authors: Robert K. Wayne et al.

It is not so up to date, almost 10 years old but it gives some good idea:

"The archaeological record cannot resolve whether domestic dogs originated from a single wolf population or arose from multiple populations at different times . However, circumstantial evidence suggests that dogs may have diverse origins. During most of the late Pleistocene, humans and wolves coexisted over a wide geographic area, providing ample opportunity for independent domestication events and continued genetic exchange between wolves and dogs. The extreme phenotypic diversity of dogs, even during the early stages of domestication also suggests a varied genetic heritage. Consequently, the genetic diversity of dogs may have been enriched by multiple founding events, possibly followed by occasional interbreeding with wild wolf populations."

"We sequenced portions of the mitochondrial DNA of wolves and domestic dogs. Initially, 261 base pairs (bp) of the left domain of the mitochondrial control region (5) were sequenced from 140 dogs representing 67 breeds and five cross-breeds and 162 wolves representing 27 populations from throughout Europe, Asia, and North America. Because all wild species of the genus Canis can interbreed and thus are potential ancestors of the domestic dog, five coyotes (Canis latrans) and two golden, two black-backed, and eight Simien jackals (C. aureus, C. mesomelas, and C. simensis, respectively) were also sequenced."

As a full even simplified conclusion of the mitochondrial DNA analysis it was found that:

"No dog sequence differed from any wolf sequence by more than 12 substitutions, whereas dogs differed from coyotes and jackals by at least 20 substitutions and two insertions. These results clearly support wolf ancestry for dogs. However, because mitochondrial DNA is maternally inherited, interbreeding between female dogs and male coyotes or jackals would not be detected. More limited studies of nuclear markers support the conclusion that the wolf was the ancestor of the domestic dog."

Thanks for asking NEWTON! and i hope to see you again! Volte com outras perguntas!

Mabel
(Dr. Mabel M. Rodrigues)



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