Pooches look up at people with quizzical, pleading eyes that are tough to resist. Now, research suggests evolution played a role in that irresistible gaze.
Dogs were domesticated more than 33,000 years ago and have changed over time to communicate with people, the study authors noted.
Dogs' eyebrows are particularly expressive. Dogs can raise them, which makes their eyes look bigger and sadder, like humans can, according to Juliane Kaminski, a scientist at the University of Portsmouth in England, and her colleagues.
For the study, Kaminski's team compared the anatomy of dogs' faces and those of wild wolves. They also compared the behavior of wolves and shelter dogs.
In dogs, the researchers found a muscle that raises the eyebrows, which wolves didn't have. The muscle in dogs pulls the corner of the eyelids toward the ears.
Only the Siberian husky, an ancient breed, was missing this muscle, the investigators found.
The report was
ed June 17 in the Proceedings of the National Academy of Sciences.
Compared to wolves, dogs often raised their eyebrows more intensely when humans were around. The anatomy and behavior suggest that dogs evolved to appeal to people, the researchers said in a journal news release.
Dogs were domesticated more than 33,000 years ago and have changed over time to communicate with people, the study authors noted.
Dogs' eyebrows are particularly expressive. Dogs can raise them, which makes their eyes look bigger and sadder, like humans can, according to Juliane Kaminski, a scientist at the University of Portsmouth in England, and her colleagues.
For the study, Kaminski's team compared the anatomy of dogs' faces and those of wild wolves. They also compared the behavior of wolves and shelter dogs.
In dogs, the researchers found a muscle that raises the eyebrows, which wolves didn't have. The muscle in dogs pulls the corner of the eyelids toward the ears.
Only the Siberian husky, an ancient breed, was missing this muscle, the investigators found.
The report was
ed June 17 in the Proceedings of the National Academy of Sciences.
Compared to wolves, dogs often raised their eyebrows more intensely when humans were around. The anatomy and behavior suggest that dogs evolved to appeal to people, the researchers said in a journal news release.
xceeded that of unprocessed red meat.
ReplyDelete"Despite strong evidence linking processed meat with cancer risk, consumption of processed meat among U.S. adults didn't change over the study period [1999-2016]," noted lead investigator Dr. Fang Fang Zhang, from Tufts University's School of Nutrition Science and Policy in Boston.
"While factors other than health [e.g., social, cultural and economic] can influence Americans' food choices, the lack of widespread awareness of health risks associated with processed meat may have contributed to the lack of consumption change," she added in a news release from the Academy of Nutrition and Dietetics.
The researchers analyzed data gathered between 1999 and 2016 on the eating habits of U.S. adults, 20 and older.
Over those 18 years, consumption of processed meats stayed about the same, 182 grams/week in 1999 and 187 grams/week in 2016.
The top five types of processed meats consumed in 2015-2016 were: luncheon meat (39%), sausage (24%), hot dogs (9%), ham (9%) and bacon (5%).
Consumption of unprocessed red meat during the study period fell from 340 grams/week to 284 grams/week, primarily due to a decline in beef consumption.
Poultry consumption rose from 256 grams/week to 303 grams/week, primarily due to a 34-grams/week increase in consumption of chicken.
Fish and seafood consumption remained about the same, 115 grams/week compared with 116 grams/week, according to the study.
The researchers noted that the low consumption of fish and shellfish could be a result of high retail prices, lack of awareness of the health benefits, and concerns about mercury contamination in certain fish. But, they added, scientific evidence suggests that the benefits of fish intake exceed the potential risks for most people.
"Our findings support further actions to increase the public awareness of the health risks associated with high processed meat consumption in the U.S.," Zhang said.