New study finds : penguins have remarkably little taste , because the birds are missing genes that produce taste receptors for bitter, sweet and a savory taste called umami.
All penguins – of all types – have been discovered to have no taste for sweet, bitter, and umami flavors of edible matter. Of course they can’t taste anything sweet, even if it happens to be a sweet-tasting rock – but this finding is linked inextricably to eating. As it turns out, its likely penguins lost their taste for several types of food over the course of their migration to cold climates and evolution to the creatures they are today – friendly, tasteless waddlers though they are.
As tastes such as these don’t often appear in the bitter cold, penguins simply did not need to have the genes to detect them. That’s what a team of researchers has concluded after sequencing the genomes of a couple of penguin tribes: Adelie and emperor penguins.
According to Jianzhi “George” Zhang of the University of Michigan, “Penguins eat fish, so you would guess that they need the umami receptor genes, but for some reason they don’t have them.”
Zhang is co-author of the paper being published on the subject this week in the journal Current Biology. “These findings are surprising and puzzling, and we do not have a good explanation for them. But we have a few ideas.”
The team also mapped the genes of the Chinstrap penguin, Rockhopper penguin, King penguin, Antarctic petrol, Northern fulmar, Manx shearwater, Streaked shearwater, Bonin islands petrel, Leach’s storm petrel, Black-footed albatross, Little egret, and Red-throated loon.
The ability to taste depends upon proteins called receptors. Those receptors nestle in the outer membrane of cells in the taste buds. Once receptors detect the molecules responsible for a particular taste, the receptors send a message to the brain about what’s tripping across the tongue.