Humans have a long evolutionary relationship with ethanol, pre-dating anthropogenic sources, and possess unusually efficient ethanol metabolism, through a mutation that evolved in our last common ancestor with African great apes. Increased exposure to dietary ethanol through fermenting fruits and nectars is hypothesized to have selected for this in our lineage. Yet, other mammals have frugivorous and nectarivorous diets, raising the possibility of natural ethanol exposure and adaptation in other taxa. We conduct a comparative genetic analysis of alcohol dehydrogenase class IV (ADH IV) across mammals to provide insight into their evolutionary history with ethanol. We find genetic variation and multiple pseudogenization events in ADH IV, indicating the ability to metabolize ethanol is variable. We suggest that ADH enzymes are evolutionarily plastic and show promise for revealing dietary adaptation. We further highlight the derived condition of humans and draw attention to problems with modelling the physiological responses of other mammals on them, a practice that has led to potentially erroneous conclusions about the likelihood of natural intoxication in wild animals. It is a fallacy to assume that other animals share our metabolic adaptations, rather than taking into consideration each species' unique physiology.

中文翻译：

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哺乳动物乙醇代谢广泛变化的遗传证据：重新探究自然中毒的“神话”。

人类与乙醇有着很长的进化关系，早于人为来源，并且由于我们在非洲大猿的最后一个祖先中发生的突变而拥有异常有效的乙醇代谢。据推测，在我们的血统中已经选择了通过发酵水果和花蜜来增加膳食乙醇的暴露。然而，其他哺乳动物具有节食性和肉食性饮食，这增加了天然乙醇暴露和适应其他生物分类的可能性。我们对哺乳动物中的酒精脱氢酶IV类（ADH IV）进行了比较遗传分析，以了解其在乙醇中的进化史。我们在ADH IV中发现遗传变异和多个假基因事件，表明代谢乙醇的能力是可变的。我们建议ADH酶在进化上是可塑性的，并显示出揭示饮食适应性的希望。我们进一步强调了人类的衍生条件，并提请人们注意对其他哺乳动物对它们的生理反应进行建模的问题，这种做法已导致对野生动物自然中毒可能性的潜在错误结论。假设其他动物共享我们的代谢适应能力，而不是考虑每种物种的独特生理学，这是一个谬论。