WASHINGTON Cheap Nike Air Max 90 Leather Australia , Feb. 16 (Xinhua) -- Penguins apparently can't enjoy the savory taste of the fish they eat, according to a genetic study conducted by Chinese and U.S. researchers that suggested the flightless, waddling birds' adaptation to an extreme cold environment may come at a price.

The study, published Monday in the U.S. journal Current Biology, found that penguins have lost three of the five basic tastes -- sweet, bitter and the savory, meaty taste known as umami -- more than 20 million years ago and never regained them.

For these birds Cheap Nike Air Max 90 Ultra 2.0 Australia , it appears that food comes in only two flavors: salty and sour.

"Penguins are often viewed as a success story of adaptation to a very harsh environment," study leader Jianzhi Zhang, professor of the University of Michigan, told Xinhua. "Apparently there were failures in this adaptation."

Because penguins are fish eaters, the loss of the umami taste is especially surprising, said Zhang.

"Penguins eat fish, so we expected that they have the umami taste genes Cheap Nike Air Max 90 Mens Australia ," he continued. "But for some reason they don't have them ... we do not have a good explanation."

Compared with mammals, birds are thought to be poor tasters, due in part to the observations that they have fewer taste buds on their tongues and lack teeth for chewing food.

Previous genetic studies showed that the sweet taste receptor gene is absent from the genomes of all birds examined to date.

The penguin study was prompted by an email from BGI, a genomics institute in China, where researchers had sequenced genomes from Adelie and emperor penguins and could not find some of the taste genes, Zhang said.

They took a closer look at the penguin DNA to find that all penguin species lack functional genes for the receptors of sweet, umami Cheap Nike Air Max 93 Australia , and bitter tastes.

Penguins originated in Antarctica after their separation from tubenose seabirds around 60 million years ago, and the major penguin groups separated from one another about 23 million years ago. The taste loss likely occurred during that 37-million-year span, which included periods of dramatic climate cooling in Antarctica, Zhang said.

The researchers suggested that genes encoding those taste receptors may have been lost in penguins not because they weren't useful, but rather because of the extremely cold environments in which penguins live.

Unlike receptors for sour and salty, the taste receptors required for detecting sweet, umami Cheap Nike Air Max 180 Australia , and bitter tastes are temperature sensitive and don't work when they get really cold. In other words, even if penguins had those taste receptors, the receptors wouldn't be much use to many of them, the researchers said.

Penguin tongues are also unusual in other ways, the researchers noted.

Previous studies have suggested that some penguins lack taste buds -- the primary location for taste receptors -- altogether. Instead, penguin tongues have stiff, sharp papillae covered by a thick Cheap Nike Air Max 1 Australia , horny layer, suggesting that their tongues are used not so much to taste food, but rather to catch and hold onto it, they said.

Penguins also have a habit of swallowing their food whole, which might leave them less concerned about what their food actually tastes like.

"Their behavior of swallowing food whole, and their tongue structure and function, suggest that penguins need no taste perception Cheap Nike Air Max 270 Australia , although it is unclear whether these traits are a cause or a consequence of their major taste loss," Zhang said.

Although all penguins originated in Antarctic, some subsequently migrated out and now live in the temperate zone.

"I have been asked whether these temperate penguins have the sweet, umami and bitter tastes," Zhang said. "The answer is no, because these tastes were already gone in the common ancestor of all penguins and cannot be regained once lost."

MADRID, March 8 (Xinhua) -- Matchday 26 in the Spanish BBVA Primera Liga saw FC Barcelona leapfrog Real Madrid into first place at the top of the table.

Real Madrid suffered a 1-0 defeat away to Athletic Club Bilbao on Saturday afternoon in a game decided not only by Aritz Aduriz's towering 26th minute header Cheap Nike Air Max 360 Australia , but also by the team-work and spirit of the home side, who produced one of their most complete displays of the season despite injuries in central midfield and having ended their Kings Cup semi-final away to Espanyol just 68 hours before kickoff.

Real Madrid's much vaunted attacking trio of Cristiano Ronaldo, Gareth Bale and Karim Benzema were nullified by the Athletic defense and the closest they came to scoring was a miss-hit cross from Bale which surprised Athletic keeper, Gorka Iraizoz and bounced back off the post.

Madrid's defeat opened the door for Barca to move into first spot and in front of the biggest crowd of the season in the Camp Nou, Luis Enrique's side made the most of a midday kick to hammer Rayo Vallecano 6-1.

Rayo had conceded 31 goals in their previous 7 games against Barca and that story was to continue on Sunday. Luis Suarez opened the scoring after just 6 minutes and although there were no further goals in the first half, the floodgates opened after the break.

Gerard Pique scored Barca's second three minutes after the break before Leo Messi netted a 12 minute hat-trick to spark widespread celebrations from the stands. Dani Alves was sent off for committing a penalty which allowed Alberto Bueno to score Rayo's consolation goal, but Suarez's second of the game rounded off the scoring.

Both Alves and Jordi Alba will both be suspended next weekend for Barca Cheap Nike Air Max 95 Australia , but that means they will be available for the following week's Classico at home to Real Madrid, which looks as if it would well be a title deciding game.

The battle for third place is still wide open after Atletico Madrid and Valencia drew 1-1 in the Vicente Calderon Stadium. Koke's excellent strike put Atletico ahead in the 33rd minute, but Atletico paRoad Initiative, the two s. Cheap Air Max 2017   Air Max 2017 Sale   Cheap Nike Air Max   Cheap Air Max Shoes   Cheap Air Max 2017 Online   Cheap Air Max 90 Shoes   Cheap Air Max 90 Online   Cheap Air Max 97 Online   Air Max 2018 Womens Sale   cheap air max 2017 online