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.
Above you’ll see a chart of genes as they appear in several animals. The following is true:
Tas1r2 Sweet taste receptor gene
Tas1r1 Umami taste receptor gene
Tas1r3 Sub-unit in both sweet and umami
Tas2r1 and 2 Bitter taste receptor
NOTE: Umami can also be described as a “pleasant, savory taste.”
It’s not just penguins who aren’t able to taste the same as humans. Imagine that! Who would have thought a Black-footed albatross had a less-than-perfect set of taste receptors for bitter foods?
How about that?
The paper goes by the name “Molecular evidence for the loss of three basic tastes in penguins” and was authored by Huabin Zhao, Jianwen Li, and Jianzhi Zhang.
Zhao hails from the Department of Zoology, College of Life Sciences, Wuhan University, Wuhan 430072, China and the Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109, USA. Zhang also works with the Department of Ecology and Evolutionary Biology. Li comes from the China National GeneBank, BGI-Shenzhen, Shenzhen, 518083, China.