This article by Dr Doug Knueven in Dogs Naturally Magazine explains recent research on lupine/canine adaptation to a human diet. The research shows evidence that part of the genetic adaptation which occurred as wolves became dogs was an ability to process carbohydrates found in some of the dogs that were studied.
The title of Dr. Knueven’s article is rather provocative and is meant to be so. As you read further in the article you find the good Dr. has a balanced approach toward the research. After careful consideration, he concludes that, while some dogs carry genes that may enable them to thrive on a starchy diet; the vast majority of dogs will continue to get the most benefit from a grain-free ancestral diet.
My conclusion: Dogs eat meat. If they eat kibble, they will benefit most from kibble that contains the most meat.
Just as Dr. Knueven predicts, I believe this study will be used by the big dog food manufacturers to defend their extensive use of grain fillers.
On a related note: I had the opportunity last September to watch two wolves devour a good sized mule deer doe. They did not eat the stomach contents. They tore into the animal through the rectal area and proceeded to rip off and consume large hunks of tissue from the haunches and back area. The next day the stomach and contents were still largely intact. Corvids (ravens & crows) were working the carcass over by this time.