2021年经济学人 会唱歌的鸟儿爱吃糖(1)

Science & technology

科技板块

The origin of songbirds

鸣禽的起源

The sweet taste of success

成功的甜蜜滋味

Songbirds can detect sugar. That may explain their ubiquity

鸣禽可以探测到糖，这或许可以解释它们无处不在的原因

Imagine a world without bird song.

想象一个没有鸟儿歌唱的世界。

Yet this might have come about if it had not been for a genetic² change that happened some 30m years ago, at the beginning of the evolution of the Passeri, to give songbirds their proper name.

然而，如果不是大约3000万年前雀形目进化初期发生的基因变化给了鸣禽真正的名字，可能这个世界就真的没有鸟儿歌唱。

Birds evolved from carnivorous dinosaurs³ called theropods.

鸟类是从食肉恐龙进化而来的。

Meat eaters need not detect sugar in the way that, say, fruit eaters do, and genetic analyses of modern birds suggest their theropod ancestor had lost the ability to taste sweetness.

肉食者不需要像水果食者那样检测糖分，对现代鸟类的基因分析表明，它们的兽脚亚目祖先已经失去了品尝甜味的能力。

Today, however, many birds have sugar-rich diets of nectar or fruit, so perceiving things as sweet is a useful attribute.

然而，今天，许多鸟类以富含糖分的花蜜或水果为食，所以“感知事物是甜的”是一个有用的属性。

And research just published in Science by Toda Yasuka of Tokyo University and Maude Baldwin of the Max Planck Institute for Ornithology⁴ in Seewiesen, Germany, suggests songbirds can indeed perceive sweetness.

东京大学的户田康嘉和德国许威森的Max Planck鸟类研究所的莫德·鲍尔温刚刚在《科学》杂志上发表了一项研究，表明鸣禽确实能够感知甜味。

This reevolved ability may have been instrumental in their success. Since almost half the bird species now alive are Passeri, that is no small matter.

这种再进化的能力可能对它们的成功起到了重要作用。因为现在几乎一半的鸟类都是雀形目，这不是一件小事。

Vertebrates' taste-receptor genes⁵ normally include three that encode proteins called T1R1, T1R2 and T1R3.

脊椎动物的味觉受体基因通常包括三个编码T1R1、T1R2和T1R3的蛋白质。

The taste receptors themselves are formed from pairs of these proteins.

味觉感受器本身就是由这些成对的蛋白质组成的。

Receptors for sweetness are a combination of T1R2 and T1R3. Birds, however, lack the gene¹ for T1R2.

甜味受体是T1R2和T1R3的组合。然而，鸟类缺乏T1R2基因。

Presumably, it was lost by their theropod ancestors, which did not need it. Dr Toda's and Dr Baldwin's experiments have shown how this loss was reversed.

据推测，它是兽脚亚目动物的祖先遗失的，它们并不需要它。户田博士和鲍德温博士的实验显示了这种损失是如何逆转的。

The pair's first study, published in 2014, was on hummingbirds⁶, which feed on nectar from flowers.

他们的第一个研究发表于2014年，研究对象是以花蜜为食的蜂鸟。

It found that hummingbirds regained⁷ the ability to taste sugars via mutations in the genes for T1R1 and T1R3.

研究发现，蜂鸟通过T1R1和T1R3基因的突变重新获得了尝糖的能力。

The receptor formed by combining T1R1 and T1R3 normally detects umami, a savoury flavour typical of meat.

由T1R1和T1R3组合而成的受体通常能检测鲜味，即肉的一种典型的咸味。

In hummingbirds, these mutations allow this receptor to detect sugars, too.

在蜂鸟身上，这些突变也让这种受体能够检测糖。

Dr Toda and Dr Baldwin therefore wondered whether that was also the case for songbirds.

户田博士和鲍德温博士因此想知道鸣禽的情况是否也是如此。

1 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

2 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

3 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

4 ornithology   

n.鸟类学

参考例句：

• He found his vocation in ornithology.他发现自己适于专攻鸟类学。
• His main interests are botany and ornithology.他主要对植物学和鸟类学感兴趣。

5 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

6 hummingbirds   

n.蜂鸟( hummingbird的名词复数 )

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious. 蜂鸟发现花蜜和花粉是很有营养的。
• Why do hummingbirds and gorillas both have backbones? 为什么蜂鸟和大猩猩都有脊骨？

7 regained   

复得( regain的过去式和过去分词 )； 赢回； 重回； 复至某地

参考例句：

• The majority of the people in the world have regained their liberty. 世界上大多数人已重获自由。
• She hesitated briefly but quickly regained her poise. 她犹豫片刻，但很快恢复了镇静。