What was discovered?
Discovery done by Gary Beauchamp and his team
· Mammals have 5 taste receptors: Bitter, Sour, Salty, Sweet, Umami (amino acids)
· 12 different species were tested, including a cat-like animal called Fossa, Spotted Hyenas, and sea mammals
· Carnivores have inactive sweet gene caused by a mutation of the Tas1r2 gene. Seven mammals had varied degrees of broken encoding gene for sweet taste. Land mammals had different mutations of the gene. Some sea mammals that were closely related had similar mutations.
· Does not mean they do not consume sweet things, Lions consume zebras which have high levels of sugar stored in their muscles.
· Other animals have lost other receptors. Bottlenose dolphins and sea lions have inactive umami receptor because they swallow food whole.
Why it important
· Shows convergent evolution is occurring because there is diversity in the mutation of the gene Tas1r2.
· Mutations don’t always hurt animals and there is no evidence saying it is a benefit either.
· Gary Beauchamp and his team published a paper in 2005 about how house cats and some big cats like tigers and cheetah have lost the ability to detect sweets. After their paper was publish they got lots of emails telling them that peoples cats eat ice cream and other sugary thing, but they are baffled as to why.
By Sara Cady
6. Callaway, Ewen. "Carnivores Pick Meats over Sweets." Nature.com. Nature Publishing Group, 12 Mar. 2012. Web. 20 Mar. 2012. http://www.nature.com/news/carnivores-pick-meats-over-sweets-1.10207
7. Li, X. et al. PLoS Genetics http://dx.doi.org/10.1371/journal.pgen.0010003 (2005)