London, July 29 : A boozy night might leave you with the most excruciating hangover the next morning, but this doesn't hold true for one of our distant mammalian cousins- the tree shrews.
These pen-tailed tree shrews, related to the ancestors of primates, eat giant flower clusters of the stemless bertam palm in the rainforests of Malaysia.
The palm's floral nectar has sugars that ferment in the warm, moist environment, and produce alcohol with a concentration of 3.8 percent with a mean concentration of about 0.6 percent - similar to that of beer.
Frank Wiens of the University of Bayreuth, Germany, carried out this study and insisted that because the nectar makes up an important ingredient of the shrews' diet, one may take into account their taste for alcohol to understand the evolutionary forces that coerce humans to drink.
The reason behind the alcohol content of the nectar lies in the flower structure, which initiates fermentation, apparently to attract mammalian pollinators.
But the tree shrews do not seem to get drunk, despite consuming alcohol, even one third of which is enough to intoxicate them if they had a human-like metabolism.
And the key to their sobriety lies in their fur- metabolic byproduct called ethyl glucuronide (EtG).
Apparently, tree shrews convert most of the alcohol they consume into EtG, which ends up in their fur. This compound is seen at levels normally found only in severely alcoholic humans although humans convert only a little alcohol into EtG.
"It's a beautiful example of the natural biology of alcohol consumption, which people have totally neglected in alcohol research," New scientist quoted Robert Dudley of the University of California at Berkeley, as saying.
Earlier Dudley had suggested that our taste for alcohol may be an "evolutionary hangover" from our fruit-eating primate ancestors, who developed a taste for fermented fruit.