Mmm, tastes like chicken: Common ancestors could account for phenomenon
By Byron Spice, Science Editor, Post-Gazette
It was inevitable.
Once the castaway contestants on CBS's "Survivor" had their first rat skinned and sizzling over the fire, everyone knew what would come next.
Tastes like chicken, they reported.
Why should rats on the South Pacific isle of Pulau Tiga-- apparently the descendants of shipwrecked common black rats, the species Rattus rattus -- taste like chicken, Gallus gallus?
For that matter, why did Uncle Hank insist that, if you ignored the buckshot, those squirrels he bagged tasted just like chicken? Remember the day Mom served rabbit? Bet it tasted like chicken.
Why do so many meats taste like chicken?
One obvious answer is that they don't. It's simply more comforting to think you're feasting on Sunday chicken than munching on an animal associated with garbage bins. "As poor as we got in the ghetto, we never ate rats," observed Ramona Gray, a 29-year-old chemist from Edison, N.J., just before the famished competitor began gnawing on a rat leg in "Survivor's" third episode.
Ruth Adams Bronz, a culinary author, former restaurateur and host of a radio food show in western Massachusetts, said a rat's diet in a nonurban habitat is actually pretty healthy -- nuts, berries, fruits. Consequently, island rat probably doesn't taste that bad, though her advice would be to disguise it a bit.
"Get the skeleton out of that rat," she suggested. "Get the tail away from the table. Don't let anyone see an ear."
Bronz didn't volunteer to do any taste-testing of her own, however.
Another reason why rat and so many other meats taste like chicken is that skinned, boned chicken breast is just so darn bland. The muscle itself, she said, doesn't have much flavor.
"What gives meat its flavor is the fat," Bronz said, and the feed given commercial chickens is meant to produce innocuous fat. By contrast, a free-range chicken that eats a more varied diet has a distinctive taste, thanks to its more flavorful fat. "Chickens are very sensitive to their feed," she noted.
When you remove skin and fat from the already mild commercial chicken meat, what's left tastes pretty plain. "That's why when you say something tastes like chicken, what you're saying is it doesn't taste like anything at all," she said.
Mark Mattern, senior chef instructor at the Disney Institute in Orlando, Fla., agrees with the tasteless description, though he emphasizes the role of glutamate and "rigor" in altering meat's "mouthfeel." Chicken breast has low levels of glutamate, the chemical associated with the "fifth taste" known as umami, which is savory rather than sweet, sour, bitter or salty. Chicken muscle also has little rigor, the quality that determines a meat's toughness.
After sufficient processing, which lowers glutamate levels and tenderizes the meat, almost any meat can be made to taste like chicken, said Mattern, a North Hills native.
An ordinary person might let the whole matter go at that, but Joe Staton, an evolutionary biologist at the University of South Carolina, several years ago launched a whole new field of study -- culinary evolution -- to root out the origins of chicken flavor.
Actually, he was less interested in answering the burning question of why so many cooked meats taste like chicken than in finding a way to teach evolutionary principles to easily bored undergraduates. "This makes them laugh," he explained.
One of the ideas he wanted to get across is how an organism's different traits have different evolutionary origins -- some are inherited from thousands or perhaps millions of generations of ancestors and shared with other related species, while others have been acquired more recently and are less widely shared, if at all.
So Staton, then at the Museum of Comparative Zoology at Harvard University, set out to determine if a creature's taste is something that it evolves independently, or inherits from an ancient ancestor. He went to supermarkets that sell exotic meats, gathered up as many types of meats as he could find, and began his gustatory exploits.
In cases where he wasn't able or willing to sample a meat type, he relied on either experts or "common knowledge." He then plotted the flavor results on a phylogenetic tree, a diagram that shows which kinds of animals evolved from which other animals.
It's a task he approached lightheartedly. In fact, his analysis was published two years ago in the Annals of Improbable Research, the tongue-in-cheek magazine that sponsors the annual "Ig-Nobel" awards honoring research "that cannot or should not be reproduced."
Staton, whose serious work involves studying the genetics of microscopic marine invertebrates called meiofauna, said his aim was to have some fun with the evolution of taste. "But the data are real, to the best of my knowledge," he added.
He concluded, not surprisingly, that the cooked flavor of meat generally is something that developed with a common ancestor of all "tetrapods" -- four-limbed creatures with a backbone. Taste is not something that seems to have evolved independently in creatures that have similar tastes, he said.
"They all taste the same," Staton said, "because they all have a common ancestor."
Muscle is muscle.
Certainly, almost all birds taste like chicken. The only odd bird Staton found was the ostrich, which has a more beef-like flavor. He attributed the difference to the dense system of blood vessels required to feed the big bird's muscular legs.
Mammal meat was a little harder to fit into a pattern. Differences in hemoglobin and myoglobin levels in mammal meat -- perhaps related to different ways that mammals manage their internal temperatures -- result in different tastes.
He maintains it's impossible to determine whether the beefy flavors of hoofed mammals evolved before pork-like flavors.
And humans, in case you were wondering, have a pork-like flavor, Staton noted, emphasizing that he was basing this observation only on hearsay. Cannibals have been known to refer to humans as "long pork."
Bronz noted that humans, like pigs, carry their fat on the outside, rather than marbled through the muscle like beef cattle.
Staton couldn't bring himself to try mouse meat, much less sample the rats so popular on "Survivor." He stopped short of predicting how it might taste, noting that a close relative, muskrat, has a beefy flavor, while another close relative, rabbit, tastes like chicken.
But there are those who have sampled mouse meat, like outdoor writer Farley Mowat. In his book, "Never Cry Wolf," Mowat described mouse meat as "pleasing, if rather bland."
Why he didn't just say, "Tastes like chicken," we can only guess.
Amphibians and reptiles such as salamanders, frogs and turtles also have chicken-like flavor.
Seafood has its own flavor, which evolved even earlier than the tetrapods. But, again, "crabs taste like lobsters because they both evolved from the same group of crabby-lobstery-tasting crustaceans."
It's possible to use this evolutionary approach to predict how certain creatures tasted, Staton said. Dinosaurs, for instance, evolved after reptiles. Birds, according to many scientists, may have evolved from dinosaurs.
So what was the flavor of Tyrannosaurus rex, the carnivorous dinosaur that some scientists are now arguing should be called Manospondylus gigas?
By either name, it tasted like chicken.