猫狗之争：从进化角度看猫科比犬科更好

 　　It's the debate that has long divided animal lovers. Now scientists have confirmed that cats really are better than dogs – at least from an evolutionary¹ perspective.

　　一直以来，“猫和狗哪个更好”这一问题将动物爱好者划分为两大阵营。现在科学家已经证实猫确实比狗更好——至少从进化的角度来看是这样。

　　A groundbreaking study of 2,000 ancient fossils reveals that felids – the cat family – have historically been much better at surviving than the "canid" dog clan², and often at the latter’s expense.

　　一项对2000个古代化石进行的开拓性研究揭示了从历史上看，猫科动物家族的生存能力远远强于犬科动物家族，而且猫科动物的生存是以犬科动物的损耗为代价的。

　　The research finds that cats have played a significant role in making 40 dog species extinct, outcompeting them for scarce food supplies because they are generally more effective hunters. But researchers found no evidence that dogs have wiped out a single cat species.

　　这项研究发现，猫科动物在40个犬科物种的灭绝过程中发挥了重要作用。由于猫科动物通常是更有效率的捕猎者，在夺取供应不足的食物的竞争中猫科动物胜过了犬科动物。但是研究人员没有发现任何犬类动物消灭掉一个猫科物种的证据。

　　猫狗之争：从进化角度看猫科比犬科更好

　　The dog family – which includes the wolves from which today’s domesticated³ dogs are descended⁴ – originated in North America about 40 million years ago and reached a maximum diversity around 20 million years later, when there were more than 30 species on the continent. At that point, the cat family arrived from Asia.

　　犬科家族——包括现在的驯养狗的祖先狼——起源于约4000万年前的北美洲，在大约2000万年后达到了物种多样性的巅峰，当时在北美洲有超过30个犬类物种。与此同时，猫科动物也从亚洲来到此地。

　　"The arrival of cats to North America had a deadly impact on the diversity of the dog family. We usually expect changes in climate to play the overwhelming role in the evolution of species. Instead, competition among different carnivore species proved to be even more important for the dogs," said the report’s lead author, Dr Daniele Silvestro, of the University of Lausanne in Switzerland.

　　这项研究报告的第一作者、瑞士洛桑大学（University of Lausanne）的达妮埃尔·西尔韦斯特罗（Dr. Daniele Silvestro）博士表示：“猫科动物的到来给犬科动物的物种多样性造成致命打击。我们通常预计气候变化会在物种进化过程中发挥最重要的作用。但对于犬科动物来说，不同食肉动物物种间的竞争被证明是更重要的。”

　　The influx⁵ of cats prompted a period of dramatic decline among the dog clan. This has left North America with just nine species of wild dog today, comprising different variations of wolves and foxes, according to the fossil analysis published in the journal PNAS.

　　猫科动物的涌入导致犬科动物数量在一段时间内大幅下降。依据这项发表在美国国家科学院院刊（PNAS）上的化石分析，这造成了如今北美洲仅存九个犬类物种，包括狼和狐狸的不同变种。

　　Dr Silvestro says it is unclear exactly why, when times were tough, the cats were able to see off dogs so comprehensively. But he believed it could be something to do with the retractable⁶ claws that ancient cats have passed down to their domesticated descendants, but which dogs don’t have.

　　西尔韦斯特罗博士称，目前还不是十分清楚在当时的艰难岁月，猫科动物为什么能将犬科动物“驱逐”得那么彻底。但是他认为这可能跟古代猫科动物伸缩自如的爪子有关，这是犬科动物所不具有的。古代猫科动物还将这种爪子遗传给了自己的后裔家猫。

　　Millions of years ago, some dog species, such as wolves, were effective killing⁷ machines, chasing down their prey⁸ at high speed and devouring⁹ it. All surviving dog species fall into this "runner" camp.

　　数百万年前，某些犬科物种（比如说狼）是有效的杀戮机器，能以高速追捕猎物并吞食掉。所有幸存的犬科动物都属于“奔跑系猎手”阵营。

　　But other dog species ambushed¹¹ their prey in a manner similar to the cat family. However, these dogs weren’t as good as the cats at this technique – and all the canid species who used it are now extinct.

　　不过也有其他犬科动物伏击猎物的方式与猫科动物相似。然而，这些犬类动物并不像猫科动物那样擅长这项技能——所有曾使用这项技能的犬科动物现在都已经灭绝了。

　　Dr Silvestro explained: “The cats have retractable claws which they only pull out when they catch their prey. This means they don’t wear them out and they can keep them sharp. But the dogs can't do this, so they are at a disadvantage to the cats in an ambush¹⁰ situation.”

　　西尔韦斯特罗博士解释称：“猫科动物只有在抓到猎物时才会亮出它们可伸缩的爪子，这意味着它们不会磨损并能够时刻保持锋利，但是犬科动物不能做到这一点。因此，同猫科动物相比，它们在伏击方面处于劣势。”

　　The evolutionary success of carnivorous animals is strongly linked to their ability to obtain food, meaning that there can be significant competition for prey when there is insufficient¹² supply for the population.

　　食肉动物的进化成功在很大程度上与它们获取食物的能力有关，这也意味着当食肉动物的食物供应不足时，猎物的争夺将十分激烈。

　　"Felids must have been more efficient predators¹³ than most of the extinct species in the dog family," the report concluded.

　　该报告总结称：“猫科动物与那些灭绝了的犬科动物相比一定是更有效的捕食者。”

　　Vocabulary

　　felid：猫科动物

　　canid：犬科动物

　　clan：家族

　　carnivore：食肉动物

　　influx：(人或物的)大量涌入

　　retractable：可缩回的，伸缩自如的

　　prey：猎物

　　ambush：伏击

　　predator：捕食者

1 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。

2 clan   

n.氏族，部落，宗族，家族，宗派

参考例句：

• She ranks as my junior in the clan.她的辈分比我小。
• The Chinese Christians,therefore,practically excommunicate themselves from their own clan.所以，中国的基督徒简直是被逐出了自己的家族了。

3 domesticated   

adj.喜欢家庭生活的；（指动物）被驯养了的v.驯化( domesticate的过去式和过去分词 )

参考例句：

• He is thoroughly domesticated and cooks a delicious chicken casserole. 他精于家务，烹制的砂锅炖小鸡非常可口。 来自《简明英汉词典》
• The donkey is a domesticated form of the African wild ass. 驴是非洲野驴的一种已驯化的品种。 来自《简明英汉词典》

4 descended   

a.为...后裔的，出身于...的

参考例句：

• A mood of melancholy descended on us. 一种悲伤的情绪袭上我们的心头。
• The path descended the hill in a series of zigzags. 小路呈连续的之字形顺着山坡蜿蜒而下。

5 influx   

n.流入，注入

参考例句：

• The country simply cannot absorb this influx of refugees.这个国家实在不能接纳这么多涌入的难民。
• Textile workers favoured protection because they feared an influx of cheap cloth.纺织工人拥护贸易保护措施，因为他们担心涌入廉价纺织品。

6 retractable   

adj.可收回的；可撤消的；可缩回的；可缩进的

参考例句：

• a knife with a retractable blade 弹簧刀
• So, any thoughts of what you want for the retractable bed kid? 那么想为那个睡折叠床的小子做什么？ 来自电影对白

7 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

8 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

9 devouring   

吞没( devour的现在分词 )； 耗尽； 津津有味地看； 狼吞虎咽地吃光

参考例句：

• The hungry boy was devouring his dinner. 那饥饿的孩子狼吞虎咽地吃饭。
• He is devouring novel after novel. 他一味贪看小说。

10 ambush   

n.埋伏(地点)；伏兵；v.埋伏；伏击

参考例句：

• Our soldiers lay in ambush in the jungle for the enemy.我方战士埋伏在丛林中等待敌人。
• Four men led by a sergeant lay in ambush at the crossroads.由一名中士率领的四名士兵埋伏在十字路口。

11 ambushed   

v.埋伏( ambush的过去式和过去分词 )；埋伏着

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。 来自《简明英汉词典》
• The military vehicles were ambushed. 军车遭到伏击。 来自《简明英汉词典》

12 insufficient   

adj.(for，of)不足的，不够的

参考例句：

• There was insufficient evidence to convict him.没有足够证据给他定罪。
• In their day scientific knowledge was insufficient to settle the matter.在他们的时代，科学知识还不能足以解决这些问题。

13 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》