A team of scientists from the University of Michigan discovered that penguins have long since lost their ability to taste bitter and sweet flavors, as well as the meaty flavor known as umami.
The sweet, bitter and umami flavors make up three out of the five basic tastes. The other two remaining are salty and sour and researchers believe penguins can still taste these two.
The new findings revealing that penguins cannot distinguish sweet and bitter flavors were published in the journal Current Biology.
George Zhang, one of the researchers involved in the new study, explained that although penguins eat mostly fish, it would have been expected of them to be able to taste the fish meat, but they cannot.
Professor Zhang says that one of his theories point to the fact that penguins lost their ability to taste certain flavors because of the extreme cold environment in which they live.
Previous studies show that the receptor channels of the tongue, which are responsible for sending the signals to the brain regarding flavors, do not function properly at low temperatures. These studies revealed that the tongue cannot distinguish the bitter, sweet and umami flavors at very cold temperatures.
The scientists involved in the new study assume that the penguins’ ancestors lived in such cold weather that they lost the ability to taste food a long time ago.
Zhang says that the three tastes missing from penguins would not have been too useful in such harsh conditions, so nature got rid of them.
According to Zhang, gradual mutations occurred which led to the disappearance of these taste buds.
The current study is only based on genetic findings, so further studies need to be conducted on penguins to confirm whether they can or cannot distinguish three out of five flavors.
Zhang and his team of scientists are positive that future studies will prove that penguins cannot distinguish the sweet and bitter flavors, as well as the meat flavor, umami.
Image Source: penguins-world