人类通常被认为是唯一能定期摄入酒精的动物，但是科学家如今发现马来西亚的羽尾树鼩依靠一种相当于啤酒的饮食生活，而且可能已经这样生活了长达5500万年之久。树鼩被认为与所有现存灵长类动物的最晚近共同祖先非常相似，这增加了人类对酒精的敏感可能是一种进化特征的可能性。树鼩以玻淡棕榈（bertam palm）花蕾的花蜜为食。它的花蜜发酵产生了多达3.8%的酒精。这种棕榈树终年以一种复杂的时间表产生花蜜，这看上去是为了让树鼩的授粉作用最大化。相关论文发表在美国《国家科学院院刊》（PNAS）上。
Frank Wiens及其同事摄像记录了树鼩常规的夜间进食时段，并跟踪了用无线电标记的树鼩的运动，从而估计它们酒精摄入量。尽管按照人类的标准，一只树鼩在任何一个夜晚都有36%的酒醉的可能性，这组科学家没有观察到这种动物的任何酒醉的迹象。他们对毛发的生物标记物的分析证实了这种动物的高酒精摄入量，这让他们提出树鼩非常可能拥有一种有效地降解酒精的生物化学路径。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS，doi: 10.1073/pnas.0801628105，Frank Wiens，Rainer Spanagel
Chronic intake of fermented floral nectar by wild treeshrews
Frank Wiens*,†,‡, Annette Zitzmann*,§, Marc-André Lachance¶, Michel Yegles‖, Fritz Pragst**, Friedrich M. Wurst††, Dietrich von Holst*, Saw Leng Guan‡‡, and Rainer Spanagel†
+Author Affiliations
*Tierphysiologie, Universität Bayreuth, 95440 Bayreuth, Germany;
†Psychopharmakologie, Zentralinstitut für Seelische Gesundheit, 68159 Mannheim, Germany;
§Zoologisches Institut, Johann Wolfgang Goethe-Universität, 60054 Frankfurt am Main, Germany;
¶Department of Biology, University of Western Ontario, London, ON, Canada N6A 5B7;
‖Laboratoire National de Santé, Toxicologie, Université du Luxembourg, 1511 Luxemburg;
**Toxikologische Chemie, Institut für Rechtsmedizin, 14195 Berlin, Germany;
††Universitäre Psychiatrische Kliniken, 4025 Basel, Switzerland; and
‡‡Forest Research Institute, 52109 Kuala Lumpur, Malaysia
Edited by May R. Berenbaum, University of Illinois at Urbana–Champaign, Urbana, IL, and approved May 21, 2008 (received for review February 20, 2008)
Abstract
For humans alcohol consumption often has devastating consequences. Wild mammals may also be behaviorally and physiologically challenged by alcohol in their food. Here, we provide a detailed account of chronic alcohol intake by mammals as part of a coevolved relationship with a plant. We discovered that seven mammalian species in a West Malaysian rainforest consume alcoholic nectar daily from flower buds of the bertam palm (Eugeissona tristis), which they pollinate. The 3.8% maximum alcohol concentration (mean: 0.6%; median: 0.5%) that we recorded is among the highest ever reported in a natural food. Nectar high in alcohol is facilitated by specialized flower buds that harbor a fermenting yeast community, including several species new to science. Pentailed treeshrews (Ptilocercus lowii) frequently consume alcohol doses from the inflorescences that would intoxicate humans. 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.
