基因決定了你配偶的類型

Chances are, you’re going to marry someone a lot like you. Similar intelligence, similar height, similar body weight. A new study of tens of thousands of married couples suggests that this isn’t an accident. We don’t marry educated people because we happen to hang around with educated people, for example—we actively seek them out. And these preferences are shaping our genomes.

何謂緣分？緣分就是你的終成眷屬是一個與你很像的人。你們智力水平相當、身形相似，就連體重都差不多。科學家對多位夫婦進行調查後得出結論，你們之所以能夠結婚，這絕不是一個偶然。當你嫁給了一個受過良好教育的人，並不是因爲你恰好出現在他的生活中，而是我們積極的將他們尋找出來，而這種追尋源自們的基因。

“This is a very exciting paper,” says Matthew Keller, a behavioral geneticist at the University of Colorado in Boulder who was not involved with the work. “Much ink has been spilled on why mates are correlated on so many traits.”

美國科羅拉多大學波爾得分校的行爲遺傳學家Matthew Keller表示，這真的是一篇令人震驚的論文，足夠多的論據解釋了爲什麼夫妻雙方在很多方面都具有類似的特質。

To conduct the study, Matthew Robinson, a postdoc in the lab of geneticist Peter Visscher at the University of Queensland in Brisbane, Australia, and colleagues turned to large databases that include information on human physical and genetic traits. They homed in on a person’s genetic markers for traits such as height and body mass index (BMI) to predict the height and BMI of their partner. If the underlying genetic traits suggested an individual was tall, for example, their partner should also be tall. Then the researchers compared the partner’s actual height against the predicted height.

Matthew Robinson在澳大利亞布里斯班昆士蘭大學遺傳學家Peter Visscher的實驗室中做博士後工作，他和同事們將研究方向轉向了大數據，這其中包括人類生理及遺傳性狀的信息。他們通過追蹤個人的遺傳標記特徵，例如身高和身體質量指數(BMI)，來對其伴侶的相關數據進行推測。如果被測對象的潛在基因特徵是高個子，那麼他的伴侶也應該是高個子。隨後，研究人員將被測人員伴侶的實際身高和預測身高進行了對比。

When the scientists performed these calculations for more than 24,000 pairs of husbands and wives of European ancestry, they found a strong statistical correlation between people’s genetic markers for height and the actual height of their partner. They also found a statistically significant, but weaker, correlation between people’s genes for BMI and actual BMI in partners: People had actively chosen partners with similar genes to themselves, the team reports today in Nature Human Behaviour.

當科學家們對超過24000對歐洲血統的夫妻進行計算時，發現他們伴侶的預測身高和實際身高之間具有很強的相關性。同時，他們還發現伴侶的實際BMI和預測BMI之間也具有統計學意義，但是相關性較弱。研究團隊在《Nature Human Behaviour》上表示，人們會主動選擇跟自己有相似基因的伴侶。

This is evidence in humans of assortative mating, which is a form of sexual selection in which individuals with similar?traits?mate?with one another more frequently than would be expected under a random mating. It has been documented in nature, such as when more brightly colored eastern bluebirds mate with each other and when duller colored bluebirds pair up—or when big Japanese common toads mate, whereas small ones stick to themselves. Such assortative mating increases relatedness in families and can help their offspring survive better as long as the trait under selection (larger size, for example) continues to be beneficial—helping males acquire and fend off mates, for example.

這正是人類協調性交配的證據，在人類的性選擇中，個體更傾向於尋找與自己相似的交配對象，而不是隨機交配。這種例子在自然界中已經存在，例如色彩鮮豔的東部藍知更鳥會找同樣色彩豔麗的交配對象，毛色差的藍知更鳥則會找同樣毛色差的鳥兒。再比如日本蟾蜍也是大個跟大個交配，小個跟小個交配。這種協調性的交配能夠增進家族親緣關係，同時經過選擇的體徵(例如體型大小)能夠增加其後代生存的優勢，例如幫助雄性獲得配偶。

The researchers also tested for assortative mating in other traits, such as years of education, in 7780 couples in a U.K. database. They looked for concordance among partners in genetic markers previously linked to years of education, and found a remarkably high correlation. This doesn’t mean that people choose mates based on actual years of education, but it likely implies that they select for similar interests, which are associated with level of education, Robinson says.

研究人員還對其他協調交配的特徵進行了測試，例如針對英國7780對夫婦的受教育年限進行調查。結果他們發現，配偶教育年限的預測值和實際值也具有很高的相關性。Robinson說道，這並不意味着人們選擇配偶會基於對方受教育的時間，但他們卻是基於類似的標準，而這種標準和教育程度有關係。

These findings suggest that mate choice “affects the genomic architecture of traits in humans,” Robinson reported in the paper. Assortative mating boosts the odds that a trait, such as height, will be passed to offspring. That has implications for genetic models that predict how likely it is that members of a family will inherit a trait, whether it’s a disease such as schizophrenia or a physical trait, such as height.

Robinson在論文中寫道，這種交配選擇會影響人類基因組結構的特徵。協調性交配原則增加了某些體徵傳承的機率，例如身高，這種體徵則會傳給後代。這還會對基因模型造成一定影響，例如我們可以預測後代中有多大機率繼承這種特徵，以及這種被繼承的特徵是不是一種病症，例如精神分裂的物理表徵。

The next step, says Keller, is to use the new method to “understand why spouses are similar on many other, behavioral traits, such as IQ, political preference … and psychiatric disorders.” Robert Plomin, a behavioral geneticist at King’s College London, adds that new research suggests humans with autism, schizophrenia, and attention deficit hyperactivity disorder tend to marry each other, and that the new method can explore whether those choices, too, are rooted in DNA.

下一步，Keller表示會用新的方法來了解爲什麼在其它方面配偶雙方也會很相像，例如智力、政治偏好。。。甚至是精神疾病。英國倫敦大學國王學院的行爲遺傳學家Robert Plomin補充說，新的研究表明，患有自閉症、精神分類和多動症的人們也傾向於跟同類結婚。新的研究方法能夠探知這些選擇是否源自我們的DNA。

Robinson hopes to use his method to test more similarities in couples, including his own marriage. “Yes, we both have Ph.D.s and we’re both tall,” he says. “We fit the bill.”

Robinson希望用自己的方法對配偶雙方間更多的相似性進行測試，甚至包括自己的婚姻。他說，沒錯，我跟我老婆都是博士，我們長得都很高，你看，我們很符合實驗要求麼。