一夫一妻已写入基因？
In the animal world, monogamy has some clear perks.
在动物世界里，一夫一妻制有一些明显的好处。
Living in pairs can give animals some stability and certainty in the constant struggle to reproduce and protect their young—which may be why it has evolved independently in various species.
成对生活可以让动物在繁衍后代和保护后代的持续斗争中获得一定的稳定性和确定性——这可能就是一夫一妻制在不同物种中独立进化的原因。
Now, an analysis of gene activity within the brains of frogs, rodents, fish, and birds suggests there may be a pattern common to monogamous creatures.
现在，一项对青蛙、大鼠、鱼类和鸟类大脑内基因活动的分析表明，一夫一妻制生物可能有一种共同的模式。
Despite very different brain structures and evolutionary histories, these animals all seem to have developed monogamy by turning on and off some of the same sets of genes.
尽管大脑结构和进化史各不相同，但这些动物似乎都是通过开启或关闭一些相同的基因而形成一夫一妻制的。
“It is quite surprising,” says Harvard University evolutionary biologist Hopi Hoekstra, who was not involved in the new work.
哈佛大学进化生物学家霍克斯特拉说:“这相当令人吃惊。”霍克斯特拉没有参与这项新研究。
“It suggests that there’s a sort of genomic strategy to becoming monogamous that evolution has repeatedly tapped into.”
这表明有一种基因组策略可以使一夫一妻制得在进化中反复出现。
Evolutionary biologists have proposed various benefits to so-called social monogamy, where mates pair up for at least a breeding season to care for their young and defend their territory.
进化生物学家对所谓的社会一夫一妻制提出了各种各样的好处，在社会一夫一妻制中，配偶至少要在一个繁殖季节结成一对，以照顾他们的后代并保卫他们的领土。
When potential mates are scarce or widely dispersed, for example, forming a single-pair bond can ensure they get to keep reproducing.
例如，当潜在配偶稀少或广泛分散时，形成单对键可以确保他们继续繁殖。
Neuroscientist Hans Hofmann and evolutionary biologist Rebecca Young at the University of Texas in Austin wanted to explore how the regulation of genes in the brain might have changed when a nonmonogamous species evolved to become monogamous.
德克萨斯大学奥斯汀分校的神经学家汉斯·霍夫曼和进化生物学家丽贝卡·杨想要探索，当一个非一夫一妻制的物种进化成一夫一妻制时，大脑中的基因调控可能发生了怎样的变化。
For example, the complex set of genes that underlie the ability to tolerate the presence of another member of one’s species presumably exists in nonmonogamous animals, but might be activated in different patterns to allow prolonged partnerships in monogamous ones.
例如，一组复杂的基因可能存在于非一夫一妻制的动物体内，这些基因构成了一个物种容忍另一成员存在的能力的基础，但它们可能以不同的方式被激活，从而延长一夫一妻制动物之间的伙伴关系。
“We wanted to be bold—and maybe a little bit crazy” in the new experiment, Hofmann says. Instead of doing a relatively straightforward genetic comparison between closely related species on either side of the monogamy divide, he and colleagues wanted to hunt down a gene activity signature associated with monogamy in males across a wide variety of species—frogs, mice, voles, birds, and fish. So in each of these groups, they selected two species, one monogamous and one nonmonogamous.
霍夫曼说，在新的实验中，我们想要大胆一点，也许有点疯狂。他和他的同事们并没有在一夫一妻制的两个分支的近亲物种之间做一个相对直接的基因比较，而是想在各种各样的物种——青蛙、老鼠、田鼠、鸟类和鱼类——中寻找与雄性一夫一妻制相关的基因活动特征。在每一组中，他们选择了两种，一种一夫一妻制，一种非一夫一妻制。
Rounding up the brains of those animals took an international team and years of effort.
收集这些动物的大脑需要一个国际团队和多年的努力。
Hostile regional authorities and a complicated permitting system confronted the team in Romania as they tried to capture two types of a native songbird.
在罗马尼亚，敌对的地方当局和一个复杂的许可系统使这个小组在试图捕捉两种本地鸣禽时遇到了困难。
Hofmann donned scuba gear and plunged into Africa’s Lake Tanganyika to chase finger-length cichlid fish into nets.
霍夫曼戴上水下呼吸器，跳入非洲坦噶尼喀湖，将一指长的刺盖鱼捉入渔网。
Delicately debraining them while aboard a rocking boat, he says, was a struggle.
他说，在摇摇晃晃的船上小心翼翼地给他们取脑是一种挣扎。
Back the lab, the researchers then grouped roughly comparable genes across all 10 species based on similarities in their sequences.
回到实验室后，研究人员根据所有10个物种序列的相似性，对大致相似的基因进行分组。
For each of these cross-species gene groups, they measured activity based on how much the cells in the brain transcribed the DNA’s proteinmaking instructions into strands of RNA.
对于每一个跨物种的基因组，他们根据大脑中有多少细胞将DNA的蛋白质生成指令转录成RNA链来测量其活性。
Among the monogamous animals, a pattern emerged.
在一夫一妻制的动物中，出现了一种模式。
The researchers found certain sets of genes were more likely to be “turned up” or “turned down” in those creatures than in the nonmonogamous species.
研究人员发现，与非一夫一妻制物种相比，这些生物体内的某些基因更有可能被“激活”或“关闭”。
And they ruled out other reasons why these monogamous animals might have similar gene expression patterns, including similar environments or close evolutionary relationships.
他们排除了这些一夫一妻制动物可能有相似基因表达模式的其他原因，包括相似的环境或密切的进化关系。
Among the genes with increased activity in monogamous species were those involved in neural development, signaling between cells, learning, and memory, the researchers report online today in the Proceedings of the National Academy of Sciences.
研究人员今天在《美国国家科学院院刊》网络版上发表报告称，在一夫一妻制物种中，活跃度较高的基因包括了参与神经发育、细胞间信号传递、学习和记忆的基因。
They speculate that genes that make the brain more adaptable—and better able to remember—might also help animals recognize their mates and find their presence rewarding.
他们推测，使大脑更适应环境——以及更好的记忆能力——的基因也可能帮助动物识别配偶，并发现他们的存在是有益的。
It makes sense that genes involved in brain development and function would underlie a complex behavior like monogamy, says behavioral neuroscientist Claudio Mello of Oregon Health & Science University in Portland.
俄勒冈健康与科学大学的行为神经学家克劳迪奥·梅洛说，大脑发育和功能相关的基因是一夫一妻制等复杂行为的基础，这是有道理的。
But because the researchers didn’t dissect out specific brain regions and analyze their RNA production independently, they can’t describe the finely tuned patterns of gene expression in areas that are key to reproductive behavior.
但由于研究人员没有解剖出特定的大脑区域，也没有独立分析它们的RNA生成，因此他们无法描述那些对生殖行为至关重要的区域中基因表达的精细调整模式。
“It seems to me unlikely that by themselves these genes will be able to 'explain’ this behavior,” he says.
“在我看来，这些基因本身不太可能'解释’这种行为，”他说。
“The fact that they got any common genes at all is interesting,” adds Lisa Stubbs, a developmental geneticist at the University of Illinois in Urbana.
“事实上，他们有任何共同的基因是有趣的，”丽莎.斯塔伯斯补充说，她是伊利诺斯大学厄巴纳分校的发育遗传学家。
“It is a superb data set and an expert analysis,” she says, “[but] the authors have not actually uncovered many important biological insights into monogamy.”
“这是一个极好的数据集，也是一个专家的分析，”她说，“(但)作者实际上并没有发现许多关于一夫一妻制的重要生物学洞见。”
The study did turn up a curious outlier.
这项研究确实发现了一个奇怪的例外。
Some of the genes with decreased expression in most of the monogamous species showed increased expression in one of them—the poison dart frog Ranitomeya imitator.
在大多数一夫一妻制物种中表达减少的一些基因在其中一个物种中表达增加——箭毒蛙Ranitomeya的模仿者。
Young notes that in this species’s evolutionary history, fathers cared for the young before cooperative parenting evolved.
杨指出，在这个物种的进化史上，父亲在合作育儿方式进化之前就已经照顾孩子了。
As a result, these frogs may have had a different evolutionary starting point than other animals in the study, later tapping into different genes to become monogamous.
因此，在研究中，这些青蛙的进化起点可能与其他动物不同，后来它们利用不同的基因变成了一夫一妻制。
Hoekstra, who has studied the genetics of monogamy in mice, sees “a lot of exciting next steps.”
霍克斯特拉研究了小鼠一夫一妻制的遗传学，他看到了“许多令人兴奋的下一步”。
There are likely mutations in other regions of DNA that regulate the expression of the genes this study identified.
在这项研究发现的基因表达中，DNA的其他区域有可能发生突变。
But it will take more work to show a causal relationship between any particular genetic sequence and monogamous behavior.
但是要证明任何特定的基因序列和一夫一妻制行为之间的因果关系还需要更多的工作。
People also often opt for monogamy, albeit for a complicated set of social and cultural reasons.
人们也经常选择一夫一妻制，尽管是出于一系列复杂的社会和文化原因。
So, do we share the gene activity signature common to monogamous birds, fish, and frogs?
那么，我们是否拥有一夫一妻制鸟类、鱼类和青蛙共同的基因活性特征呢?
“We don’t know that,” says Hofmann, but “we certainly would speculate that the kind of gene expression patterns … might [show up] in humans as well.”
霍夫曼说:“我们不知道这一点，但我们肯定会推测，这种基因表达模式……也可能出现在人类身上。”
问题：
根据霍夫曼教授团队研究发现，一夫一妻制动物的基因变化中，哪一种动物是个例外？
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