Penguins Show Loss of Ability to Taste Fish

According it a recently released study, it has been observed that penguins have the ability to only taste salty and sour foods. Due to the evolutionary process, the species has lost three of the five basic senses for taste. While various birds like the finches or chickens do not have the ability to taste sweet foods, they do have receptors for detecting umami or bitter flavors.

All species of penguins can be traced back to Antarctica, with many species eventually moving to places with warmer climates. The researchers suspect the loss of these taste receptors could be due to extreme cold weathers conditions.

Jianzhi Zhang from the University of Michigan said, "Penguins eat fish, so you would guess that they need the umami receptor genes, but for some reason they don't have them. These findings are surprising and puzzling, and we do not have a good explanation for them. But we have a few ideas,"

The findings were recently published in the Currently Biology journal. The scientists were in for a surprise when sequenced genomes of Adelie and Emperor penguins showed the absence of certain taste genes. When this was brought to the attention of Professor Zhang, tests were conducted on all penguin species. The results showed that all species lacked the taste receptors for umami (meaty flavors), sweet and bitter tastes.

Professor Zhang added, "Their behaviour of swallowing food whole, and their tongue structure and function, suggest that penguins need no taste perception. Although it is unclear whether these traits are a cause or a consequence of their major taste loss."

One possible theory currently doing the rounds is that with flavors like bitter, sweet and umami, the taste responders do not send signals to the brain properly in extremely cold climates. This could possibly have caused the species to lose their sense of taste gradually over many years.