The science news outlets on the web were all abuzz with an odd discovery yesterday involving the symbiotic relationship between the Pentail Tree Shrew and the Bertram Palm, whose flower acts essentially as a natural brewery, creating a 3.8% abv concoction that’s closest to beer in strength and is fermented using wild yeast. My friend and colleague Rick initially sent me the NPR version of the story (thanks Rick) but it seems every science website has a version of it.
The Pentail Tree Shrew
The Pentail Tree Shrew, a native of Malaysia, seems to be the major focus of the story. The shrew is a lightweight at about 4 inches long and weighing a scant few ounces soaking wet. According to biologists studying the newly found mammals, they look like a cross between a mouse and a squirrel, with a birdlike tail that resembles a feather at the tip. They have large eyes and developed fingers and toes. Biologists believe that they are evolutionary cousins to the primates.
And like us, they spend their evenings drinking beer. In fact, they may be the only other animal to regularly drink alcohol. Scientists believe the shrew imbibes the equivalent of nine glasses of wine each night, yet would pass the average roadblock sobriety test. According to Bayreuth University biologist Frank Weins, “[t]here’s no sign of motor incoordination or other odd behaviors. They just move as efficiently as they would on any other tree.” Because being drunk would put the Pentail Tree Shrew at risk for being eaten by other jungle predators, they believe the shrew has a metabolism that very quickly detoxifies the alcohol. That would keep the concentration in the shrew’s brain low enough so that it could effectively avoid predators. And here’s the capper from Weins. “As a result, the tree shrew is able to detoxify alcohol more efficiently than its primate cousins: humans.”
The focus of almost every one of these stories is about the wonders of the shrew (because they’re the one being closely watched), but according to Scientific American, there are at least seven animals nourishing themselves from the beer made by the Bertram Palm. There’s also the Slow Loris, who also “quaff[s] alcohol nightly, sometimes going back for seconds and thirds in a single evening.”
But frankly I’m more amazed by the flower that can naturally create a beer in the wild. To me, that is simply awe-inspiring. It’s the Bertram Palm, and it’s flowers have a very pungent and distinctive smell. As Weins puts it. “They smell like a brewery.”
Or explained another way, “sugars in the palm’s floral nectar ferment in the warm, moist environment, producing alcohol in concentrations up to a beer-like 3.8%.”
Nature’s Brewery: The Bertram Palm
There’s also a description in Germany’s idw:
‘This palm is brewing its own beer with the help of a team of yeast species, several of them new to science,’ explains Wiens. The highest alcohol percentage the scientists could measure in the nectar was an impressive 3.8 %. ‘It reaches among the highest alcohol contents ever reported in natural food.’ The palm tree keeps its nectar beer flowing from specialised smelly flower buds for a month and a half before the pollen is ripe, probably to keep a guaranteed clientele of potential pollinators visiting. In contrast to most plants the bertam palm flowers almost year-round.
And here’s yet another version of how the tree makes beer, from Science News:
Bertam palms (Eugeissona tristis) don’t observe a strict season, so at any given time plants will be flowering somewhere in the forest. The stemless palms send up a tall spike with more than 1,000 flowers, some with just male sexual organs and the others hermaphroditic. For weeks before a particular sexual phase, the flower buds dribble nectar. Yeasts inside the buds typically raise the nectar’s alcohol content mildly, to around 0.06 percent, but can punch it up to as high as 3.8 percent.
“This is an astonishing story,” says John Dransfield, a palm specialist at the Royal Botanic Gardens, Kew in Richmond, England. He says he doesn’t know of another palm offering such a beer bash, but perhaps the other species secreting abundant nectar just haven’t been studied yet.
A wild mammal closely resembling the earliest primates is drinking palm beer on a daily basis since maybe millions of years. Nevertheless, this Malaysian treeshrew is never drunk. This suggests a beneficial effect, and sheds a whole new light on the evolution of human alcoholism.
From the New Scientist account:
“It’s a beautiful example of the natural biology of alcohol consumption, which people have totally neglected in alcohol research,” says Robert Dudley of the University of California at Berkeley.
Dudley has previously suggested that our taste for alcohol may be an “evolutionary hangover” from our fruit-eating primate ancestors, who developed a taste for fermented fruit.
And idw also tackles this contradiction:
Alcohol use and abuse can no longer be blamed on the inventors of brewing of about 9,000 years ago. So far, the current theories on alcoholism have stated that mankind and its ancestors were either used to take no alcohol at all or maybe only low doses via fruits – before the onset of beer brewing. As brewing is such a recent event on the evolutionary time scale, we were not able to develop an adequate defence against the adverse effects of alcohol and the partly hereditary addiction. Mankind is suffering from an evolutionary hangover, as they say. Contrary to this belief, chronic high consumption of alcohol already occurred early on in primate evolution, [according to this new study].
The beery nectar on the Bertram Palm.
The stories themselves all stem from a new study published July 28, 2008 in the Proceedings of the National Academy of Sciences of the United States entitled Chronic intake of fermented floral nectar by wild treeshrews.
From the Abstract:
Yet, the flower-visiting mammals showed no signs of intoxication. Analysis of an alcohol metabolite (ethyl glucuronide) in their hair yielded concentrations higher than those in humans with similarly high alcohol intake. The pentailed treeshrew is considered a living model for extinct mammals representing the stock from which all extinct and living treeshrews and primates radiated. Therefore, we hypothesize that moderate to high alcohol intake was present early on in the evolution of these closely related lineages. It is yet unclear to what extent treeshrews benefit from ingested alcohol per se and how they mitigate the risk of continuous high blood alcohol concentrations.
Fascinating stuff, and yet more evidence that alcohol is far more natural than the neo-prohibitionists would like. It will be interesting to see what further study reveals.