一頭大象走進酒吧，它會喝醉嗎?

一頭大象走進酒吧，它會喝醉嗎?

As early as the 19th century, elephants have had a bit of a reputation for getting “drunk” from the fruit of the marula tree in Africa. Whilst various studies have questioned these stories due to the volume of fruit they’d need to consume, other animals have also reportedly been found inebriated (from raccoons to bees).

早在19世紀，大象就因吃了非洲的馬魯拉樹的果實而有點“喝醉”的名聲。雖然各種各樣的研究對這些故事提出了質疑，因為它們需要消耗大量的水果，但據(jù)報道，其他動物也被發(fā)現(xiàn)醉酒(從浣熊到蜜蜂)。

To provide some insight into these tipsy tales, a team of researchers have looked into the genetic variations of the ADH7 gene of 85 mammals, as previous studies have linked mutations in the gene with the ability of a species to metabolize ethanol – the form of alcohol contained in beverages and that also naturally occurs from the fermentation of fruit sugars.

為了深入了解這些荒誕的故事，一組研究人員研究了85種哺乳動物ADH7基因的遺傳變異，因為之前的研究已經將該基因的突變與一個物種代謝乙醇的能力聯(lián)系起來，采用在飲料中所含的酒精的形式，它也自然地發(fā)生在水果糖的發(fā)酵過程中。

Katy Pallister

“We focused on the ADH7 gene because previous research (led by co-author Dr Matthew Carrigan) had found that humans have a mutation in this gene that makes the protein 40 times more efficient at metabolizing ethanol,” Dr Mareike Janiak, a corresponding author of the study from the University of Calgary, Canada, told IFLScience. “This evolved around 10 million years ago in our common ancestor with chimpanzees and gorillas, potentially as an adaptation for eating fruit.”

“我們之所以關注ADH7基因，是因為之前的研究(由合著者馬修·卡里根博士領導)發(fā)現(xiàn)，人類的這種基因發(fā)生了突變，使得這種蛋白質代謝乙醇的效率提高了40倍。”加拿大卡爾加里大學的通訊作者Mareike Janiak博士告訴IFLScience。“這是大約1000萬年前在我們與黑猩猩和大猩猩的共同祖先身上進化而來的，可能是為了適應吃水果。”

Curious as to whether these mutations were found in other mammals, Janiak and her colleagues mined data on the genomes of 85 species, across 21 orders, and with a variety of diets. One of the hypotheses the team were interested in was whether a diet high in fruit resulted in the selection on the ADH7 gene, seen in humans, to help them more readily metabolize ethanol. The team found the ADH7 gene sequences in 79 of the 85 mammals they investigated.

出于對是否在其他哺乳動物身上也發(fā)現(xiàn)了這些突變的好奇，Janiak和她的同事們對85個物種的基因組數(shù)據(jù)進行了挖掘。研究小組感興趣的一個假設是，富含水果的飲食是否會導致人類體內ADH7基因的選擇，從而幫助他們更容易地代謝乙醇。研究小組在他們調查的85只哺乳動物中發(fā)現(xiàn)了79只的ADH7基因序列。

“We found that many mammals that eat mostly meat or leaves actually didn’t have a functional ADH7 gene and they may have lost this gene because of the lack of fruit in their diet,” Janiak explained. However, some animals such as fruit and nectar bats, whose natural diet contains at least some ethanol, may have acquired the same human change in ADH7 to prevent them being “drunk and disorderly.”

Janiak解釋說:“我們發(fā)現(xiàn)，許多以肉類或樹葉為主要食物的哺乳動物實際上并沒有一種功能性的ADH7基因，它們可能因為飲食中缺乏水果而失去了這種基因。”然而，一些動物，如水果和花蜜蝙蝠，它們的自然飲食中至少含有一些乙醇，可能已經在ADH7中發(fā)生了與人類相同的變化，以防止它們“醉酒和混亂”。

“Being inebriated would be especially bad news for a flying mammal, so being able to better metabolize ethanol could be an important adaptation,” Janiak remarked.

“對于飛行中的哺乳動物來說，醉酒尤其是個壞消息，所以能夠更好地代謝酒精可能是一個重要的適應過程，”Janiak說。

Although it may not feel like it after a big night out, humans are up there with other African great apes as one of the mammals capable of quickly metabolizing ethanol. Others include aye-ayes, a primate found in Madagascar who are known to drink nectar, and koalas, whose eucalyptus diet contains a lot of toxins.

盡管在一夜狂歡之后可能感覺不到，但人類和其他非洲類人猿一樣，是能夠快速代謝乙醇的哺乳動物之一。其他動物包括在馬達加斯加發(fā)現(xiàn)的一種叫aye-ayes的靈長類動物，它們以喝花蜜而聞名，還有考拉，它們的桉樹食物含有大量毒素。

At the other end of the scale are those species who no longer have a functional ADH7 gene, Janiak explained. This includes bovids, carnivores, some rodents such as guinea pigs, dolphins, whales, and our old friends elephants. “Many of these species just don’t consume fruit, fresh or rotten, so they’re probably rarely exposed to ethanol,” Janiak said. “But anecdotes about elephants and horses eating rotting fruit are common.”

Janiak解釋說，在天平的另一端是那些不再具有功能性ADH7基因的物種。這包括bovids，食肉動物，一些嚙齒類動物，如豚鼠，海豚，鯨魚，和我們的老朋友大象。Janiak說:“這些物種中的許多只是不吃新鮮或腐爛的水果，所以他們可能很少接觸到乙醇。但關于大象和馬吃腐爛水果的軼事很常見。”

Whilst the lack of a functional ADH7 gene would make it easier for an animal to become inebriated, one of the study’s conclusions, published in Biology Letters, pointed out the tendency of humans to anthropomorphize animal behavior – likening an animal’s innocent unsteadiness to our drunken sways. Therefore, each story of animal intoxication should take into consideration each species’ unique physiology, rather than referring to human's drunken experiences, the authors warn.

雖然缺乏功能性的ADH7基因會使動物更容易醉酒，但發(fā)表在《生物學快報》上的一項研究結論指出，人類傾向于將動物行為擬人化——將動物的天真不穩(wěn)定比作我們醉酒后的搖擺。因此，作者警告說，每一個動物中毒的故事都應該考慮到每個物種獨特的生理機能，而不是參考人類的醉酒經歷。

Probably for the best – I'm not sure an elephant flailing round a pole in the middle of a club would end well.

也許這是最好的結果——我不確定一頭大象在棍子中間繞著一根桿子打轉會有什么好結果。