狗是人類最好的伙伴之一，已經(jīng)在人類身邊生活了數(shù)千年。讓我們一起來看看人類發(fā)展史和犬屬演變史是如何深入聯(lián)系在一起的，一起來了解這些可愛的犬科動物如何從強(qiáng)大的食肉動物演變成忠誠的保護(hù)者和家庭成員吧！

Have you ever stopped to think about the origin of doggies？ Dogs come in many different shapes and sizes. Dogs were also the first species to be tamed by human.

Long before we raised livestock， humans had lived side by side with dogs. They have been by our side for thousands of years as hunting companions， protectors and friends. It’s widely accepted by scientists that dogs are descendants of wolves. But how exactly did the fierce wild animal wolf become our family member？

Human beings became quite good at survival around 20，000 years ago. Their ability to use hand-made tools meant that they could keep most dangerous animals like wolves away. However， several wolves found that they could take advantage of humans.

Wolves could get some leftovers from hunters if they didn’t show aggression. Over a long period of time， those who showed kindness to humans got more food to eat， therefore， they had a better chance of survival and they had more babies. Over generations they became tamer. These individuals became favored by people and lost some of their predatory qualities like big sharp teeth and claws.

你可曾停下來想過狗狗們的起源？狗的外形和大小不一。狗也是第一個被人類馴服的物種。

早在我們飼養(yǎng)牲畜之前，人類就已經(jīng)與狗一起生活。幾千年來，狗作為狩獵伙伴、保護(hù)者和朋友，一直陪伴在我們?nèi)祟惿磉??？茖W(xué)家普遍認(rèn)為狗是狼的后代。但是，兇猛的野生動物——狼究竟是如何成為我們的家人的呢？

早在大約2萬年前，人類已經(jīng)非常善于生存。他們使用手工制作工具的出色能力意味著他們可以驅(qū)趕狼等大多數(shù)危險(xiǎn)的動物。然而，有些狼發(fā)現(xiàn)它們可以利用人類。

如果狼沒有表現(xiàn)出侵略性，它們可以從獵人那里得到一些吃剩的食物。在很長一段時間內(nèi)，那些對人類表現(xiàn)出善意的狼得到了更多的食物。因此，它們有了更好的生存機(jī)會，繁衍出更多后代。代代相傳，它們變得更馴服了。這些狼個體受到人們的青睞，并失去了一些掠奪性的特征，如鋒利的大牙齒和爪子。

Our histories continued to deeply connect and what resulted were the dogs. Around 15，000 years ago， early dogs moved out of Southern and Central Asia and dispersed around the world， following humans as they migrated. The relationship was a win-win situation to both species： dogs could get their regular meals instead of hunting by themselves while humans could take advantage of dogs’ super senses of hearing and smell. These puppies grew to be hunting companions， tracking and retrieving wounded game. Aside from helping humans hunt， herd and guard， dogs would have proved useful around the camp by cleaning up leftover food and huddling with humans to provide warmth.

Humans have been selectively breeding dogs to emphasize their favorable characteristics. In this way， dogs were domesticated over a long time.

Distinct dog breeds didn’t appear to be identified until 3，000 to 4，000 years ago， but most dog types we have today had been established by the Roman period. Humans still have a close and strong relationship with dogs today. And dogs are considered to be man’s best friends.

我們的人類史和犬類史繼續(xù)深深地聯(lián)系在一起，結(jié)果是狼進(jìn)化為了狗。大約1.5萬年前，早期的狗從南亞和中亞遷出，跟隨人類遷徙，分散到世界各地。這種關(guān)系對兩個物種來說都是雙贏的局面：狗不用自己捕食也可定期進(jìn)食，而人類可以利用狗超強(qiáng)的聽覺和嗅覺。這些小狗成長為狩獵伙伴，追蹤和銜回受傷的獵物。狗的作用很大，除了幫助人類狩獵、放牧和看守，狗還可以清理營地周圍剩余的食物，與人類擠在一起為他們?nèi)∨?/p>

人類一直根據(jù)自己的喜好，有選擇性地培育狗。就這樣，在很長一段時間里，狗被馴化了。

直到3000到4000年前，狗才有了清晰的分類。但我們今天大多數(shù)狗的種類都是在羅馬時期形成的。今天，人類仍然與狗有著密切而牢固的關(guān)系。狗被認(rèn)為是人類最好的朋友。

Word Bank

tame /te?m/ v. 馴化；馴服

aggression /?'ɡre?n/ n. 好斗情緒；攻擊性

retrieve /r?'tri?v/ v. 取回；索回

huddle /'h?dl/ v. （通常因寒冷或害怕）擠在一起

breed /bri?d/ v. 繁殖；培育 n. 品種