英语听力文摘 English Digest 705 狗是如何成为人类朋友的？

How Did Dogs Become “Man’s Best Friend?”

We’ve all heard the phrase “dog is man’s best friend.” But how did dogs get to be so friendly with humans? It turns out that dog domestication¹ wasn’t simply a matter of teaching Fido to play “fetch.” Scientific research indicates that genetic² selection played a key role as well.

Dog Domestication

We know that dog domestication began over ten thousand years ago. However, scientists have yet to reach a consensus³ on the details of how and why certain ancient wolves evolved into our furry⁴ canine⁵ friends.

Those details are getting clearer, though, thanks to a group of scientists working in Sweden and the United States. They analyzed⁶ the DNA⁷ from a dozen wolves and sixty dogs to determine which genetic markers distinguish domestic canines⁸. In total, 122 specific genes⁹ that could be linked to domestication turned up.

Doggie Diet

Probably the most illuminating¹⁰ discovery was the importance of three of those genes to doggie diet: they help with starch¹¹ digestion¹². It turns out that dogs possess significantly more copies of these genes than wolves do. As a result, your family pet is about five times better than its carnivorous relatives at digesting starchy foods like potatoes and rice.

This genetic evidence links the most recent phase of canine evolution to human history: during the shift from a hunter gatherer to an agricultural society, we started eating more starch, too. Waste dumps near new human settlements would have provided an ideal place for canines to scavenge food–but only if they were willing to trade in carnivorous cravings for a more starchy supper.

So, there you have it: your pooch isn’t merely your best friend–it’s also your evolutionary¹³ partner!

狗是如何成为人类朋友的？

我们都听过“狗是人类最好的朋友”这句话。但是，狗是如何与人类如此友好的呢？事实证明，驯化狗不仅仅是教菲多玩“fetch”游戏。科学研究表明，基因选择也发挥了关键作用。

狗的驯化

我们知道狗的驯化始于一万多年前。然而，科学家们尚未就某些古代狼如何以及为什么进化成我们毛茸茸的狗朋友的细节达成共识。

然而，由于一群在瑞典和美国工作的科学家，这些细节越来越清晰。他们分析了12只狼和60只狗的DNA，以确定哪些遗传标记可以区分家养犬科动物。总共发现了122个与驯化有关的特定基因。

狗狗饮食

最具启发性的发现可能是其中三种基因对狗狗饮食的重要性：它们有助于淀粉消化。事实证明，狗比狼拥有更多的这些基因拷贝。因此，你的家庭宠物在消化土豆和大米等淀粉类食物方面比它的食肉亲戚好五倍。

这一基因证据将犬类进化的最新阶段与人类历史联系起来：在从狩猎采集者向农业社会转变的过程中，我们也开始吃更多的淀粉。新人类住区附近的垃圾场将为犬科动物提供一个理想的觅食场所——但前提是它们愿意以肉食性的渴望换取更淀粉的晚餐。

所以，你就明白了：你的狗不仅是你最好的朋友，它还是你的进化伙伴！

1 domestication   

n.驯养，驯化

参考例句：

• The first was the domestication of animals. 第一个阶段是驯养动物。 来自《简明英汉词典》
• In northwestern China, there is no evidence for endemic domestication of any animals. 在中国西北，没有任何当地动物驯化的迹象。 来自辞典例句

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 consensus   

n.(意见等的)一致，一致同意，共识

参考例句：

• Can we reach a consensus on this issue?我们能在这个问题上取得一致意见吗？
• What is the consensus of opinion at the afternoon meeting?下午会议上一致的意见是什么？

4 furry   

adj.毛皮的；似毛皮的；毛皮制的

参考例句：

• This furry material will make a warm coat for the winter.这件毛皮料在冬天会是一件保暖的大衣。
• Mugsy is a big furry brown dog,who wiggles when she is happy.马格斯是一只棕色大长毛狗，当她高兴得时候她会摇尾巴。

5 canine   

adj.犬的，犬科的

参考例句：

• The fox is a canine animal.狐狸是犬科动物。
• Herbivorous animals have very small canine teeth,or none.食草动物的犬牙很小或者没有。

6 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

8 canines   

n.犬齿( canine的名词复数 )；犬牙；犬科动物

参考例句：

• For example, the teeth are more primitive. There are large canines and unusually shaped incisors. 譬如，牙齿更为原始，有大的犬齿和非常合适的门齿。 来自辞典例句
• Well-to-canines can attend doggy daycare centers while their owners work. 富人家的狗在主人上班的时候可以去狗狗托管中心。 来自互联网

9 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

10 illuminating   

a.富于启发性的，有助阐明的

参考例句：

• We didn't find the examples he used particularly illuminating. 我们觉得他采用的那些例证启发性不是特别大。
• I found his talk most illuminating. 我觉得他的话很有启发性。

11 starch   

n.淀粉；vt.给...上浆

参考例句：

• Corn starch is used as a thickener in stews.玉米淀粉在炖煮菜肴中被用作增稠剂。
• I think there's too much starch in their diet.我看是他们的饮食里淀粉太多了。

12 digestion   

n.消化，吸收

参考例句：

• This kind of tea acts as an aid to digestion.这种茶可助消化。
• This food is easy of digestion.这食物容易消化。

13 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。