You might have a sweet tooth- but apparently that meat-eating mammal you visit at the aquarium does not.  That’s the latest finding from a study published in the journal Proceedings of the National Academy of Sciences.  Co-authored by Gary Beauchamp, the director of the Monell Chemical Senses Center in Philadelphia, the study looked at DNA samples of a dozen species to look at their taste receptor genes.

The researchers knew, already, that cats don’t care for sweet carbohydrates and that they don’t have a working copy of the taste receptor gene called Tas1r2.  They thought, however, that cats were unusual.  With DNA samples primarily from the San Diego Zoo, this team joined with one from the University of Zurich to look at taste receptor genes in various mammals.

Their discoveries shocked them. Seven types of species from sea lions and Asian otters to spotted hyenas, lack the properly functioning Tas1r2 receptor. The type of mutation that each type of species had was difference, however.

And sweet wasn’t the only issue. Sea lions also showed a lack of genes that create savory tastes and dolphins showed a lack of the working genes for bitter. Beauchamp said that the findings “illustrate the fact that the sensory world of animals is highly attuned to their dietary patterns.”

This research has been deemed ground-breaking and impressive. As Thomas Finger, a neurobiologist at the University of Colorado’s Rocky Mountain Taste and Smell Center in Aurora said, the study was “pretty impressive.”