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. In the renowned scientific journal PNAS an international team led by German biologists Frank Wiens and Annette Zitzmann from the University of Bayreuth explains the details of the first recorded chronic alcohol intake in the wild.
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. In the renowned scientific journal PNAS (publication in PNAS online Early Edition scheduled for July 28), an international team led by German biologists Frank Wiens and Annette Zitzmann from the University of Bayreuth explains the details of the first recorded chronic alcohol intake in the wild.
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 an international team of scientists from Germany, Canada, Luxemburg, Switzerland, and Malaysia. First author Frank Wiens from the University of Bayreuth and the Central Institute of Mental Health in Mannheim specializes in evolutionary physiology: 'Alcohol consuming treeshrews are not real shrews. In fact, they belong to the primates' closest living relatives and are ecologically and behaviourally comparable to their extinct ancestors that lived more than 55 million years ago. Studying these fascinating creatures is an unexpected golden opportunity to learn about the causes and consequences of real-life drinking.'
Neither tipsy nor tame, the wild pentailed treeshrew Ptilocercus lowii from the West-Malaysian rainforest spends its nights looking for and licking fermented nectar of the bertam palm. '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. The alcohol consumption of treeshrews and their drinking companions - six other mammal species are also "regulars" - is therefore chronic. Chronic indeed, because this drinking habit of the pentailed treeshrew could already have been established over 55 million years ago.
As drunkenness is extremely dangerous for small mammals with plenty of lurking predators around, drinking to intoxication does not make sense. Still, with hair sample analysis for ethyl glucuronide, an indicator for chronic alcohol consumption, the team showed that the pentailed treeshrew takes in alcohol at a rate dangerous to other mammals. Treeshrews are very hard to see or catch, but video surveillance at palm sites and spying on several radio-collared individuals showed that they drank nectar for more than two hours each night - more time than they used for any other food source.
Although their size is in between that of a mouse and a rat and they weigh a mere 47 grams, they did not show any motion coordination problems or other signs of being drunk. Compared to human standards, pentailed treeshrews would be drunk once in every three nights. The treeshrews might break down the ingested alcohol in an unusually efficient manner.
That the threeshrews are not drunk does not mean that they are not affected by the alcohol in a low dose. What is more, Wiens believes that there are actually positive psychological effects of the treeshrews' alcohol consumption: 'The trait of alcohol consumption is actively maintained during evolution, so the overall effect must be beneficial. Future research has to prove if this is true and may explain past and current human drinking habits.'
Jürgen Abel | idw
UNH researchers create a more effective hydrogel for healing wounds
21.11.2018 | University of New Hampshire
Removing toxic mercury from contaminated water
21.11.2018 | Chalmers University of Technology
Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.
Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...
Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.
Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
21.11.2018 | Life Sciences
21.11.2018 | Medical Engineering
21.11.2018 | Physics and Astronomy