Monday, April 15, 2013

Wheat: How it tamed man's best friend

Wheat: How it tamed man's best friend

                                          Photo by Micki Glueckert, April 2013, copyright, all rights reserved.

Wheat gets credit for many aspects of civilization – wars over territory, the creation of cities, the development of religion, and more. New research says that wheat should get credit  for another part of civilization that most of us wouldn’t expect – the domestication of dogs.

A Nature journal article by Swedish researchers described the co-evolution of dogs’ and humans’ digestive systems. Both turned from a meaty diet to one based on grains about 10,000 years ago. Central to the ability to live on wheat, barley, and other grasses was the development of digestive enzymes, specifically amylase, that could process starches. The researchers will be exploring the dietary evolution further, along with changes in dogs’ brains that allowed the canines to befriend people and tolerate living among them.

Both humans and dogs now have genes that permit the creation of more amylase in the pancreas than their ancestors had. The enzyme helps with three key steps in the digestion of starch: breaking down large carbohydrate molecules into smaller pieces; chopping those pieces into sugar molecules; and aiding the absorption of those molecules in the intestine. Humans have additional amylase in their saliva, which lets the digestive process begin in their mouths, encouraging chewing, and making digesting food, especially grains, easier

A Washington Post article reviewed the research, with Raymond Coppinger, emeritus professor of biology and expert on dog evolution from Hampshire College in Massachusetts saying, “Humans had nothing to do with it . . . There was a new niche that was all of a sudden available for somebody to move into. Dogs are selected to scavenge off people.”

Domesticated dogs still thrive on grains, although many dog owners and food purveyors these days promote grain-free meals as more “natural.” Dog treats in particular typically include wheat, oats, barley or rice. Pup-peroni, a brand favored by my sister who breeds and raises Australian Shepherds on her show poultry farm in Michigan, produced the photo at the beginning of this post.

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