An Alcohol Gene?

            It’s interesting to think that there is actually a gene that is linked to the consumption of alcohol. Not only can this gene be found in human beings, but it is also found in other primates such as the African great apes and now, a nocturnal lemur from Madagascar, the Aye-Aye. This interesting gene mutation is known as A294V. This gene mutation is responsible for our ability to digest alcohol faster as well as having an affinity for it. In fact, this gene codes for the enzyme, alcohol dehydrogenase class IV otherwise known as ADH4. This enzyme is the first to catabolize alcohol during digestion. 

 So what exactly did researchers do to determine that the Aye-Aye had this gene mutation? Before we get there, it is important to note that the Aye-Aye spends sometime consuming fermented nectar found native in Madagascar from a plant called the Traveler’s Tree. Thus it can be noted that the Aye-Aye does have a tooth for alcohol, given the fermented nectar. Besides genetic analysis, researchers at the Duke Lemur Center in North Carolina gave groups of Aye-Ayes servings of regular tap water as well as servings of varying amounts of ethanol to simulate the fermented nectar. After running the experiment, researchers concluded that the Aye-Aye had a greater proclivity for the servings that contained higher concentrations of alcohol.

            

But does that mean that the Aye-Aye like to get wasted? Not exactly. For most animals, there is a selective advantage of consuming fermented foods over unfermented foods. In fact, fermented foods tend to have more calories. Interestingly enough, given that humans, chimpanzees, and gorillas all share this A294V gene mutation, it must mean that the affinity for alcohol or other fermented foods was apart of the human genetic makeup far before the modern human came about. That being said, before alcohol became something that made parties more fun, it was actually something that provided our ancestors with a greater caloric intake in order to perform more activities.  

 
(http://www.livescience.com/55470-aye-ayes-adore-alcohol.html)