【英语时差8,16】东方的狗

Have you ever taken a good look at your dog and wondered, where did this creature come from? Sure, you know your dog came from the local shelter or a pet store, but what about before that? If you were able to trace your dog's lineage back to its origins, what would you find?  Until recently, scientists believed that domestic dogs originated in the Middle East. But reports suggest that almost all domestic dogs began in East Asia as the offspring of three lineages. Virtually all domesticated¹ dogs in the United States descend² from dogs brought over by ancient people that crossed the Bering land bridge from Asia to North America. Although the New World had a healthy wolf population that might have given rise to a New World strain of domesticated dogs, by and large these ancient immigrants stuck with the dogs of Asian origin.

How, you may wonder, have scientists come to these conclusions? The same way forensic³ specialists increasingly solve crimes--through DNA⁴ evidence. Since mitochondria are cellular⁵ elements passed from mother to pup, mitochondrial DNA readily reveal genetic⁶ footprints stretching back into prehistoric⁷ times. Scientists from the Smithsonian Institution in Washington, D.C. collected DNA samples from the remains⁸ of ancient Old World dogs, ancient New World dogs, and ancient New World wolves. Test showed decisively that the New World dogs were genetically⁹ more similar to Old World dogs than to New World wolves, effectively proving that the dogs we save from local shelters originally hail from the far East rather than the woods of North America. 

1 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》

2 descend   

vt./vi.传下来，下来，下降

参考例句：

• I hope the grace of God would descend on me.我期望上帝的恩惠。
• We're not going to descend to such methods.我们不会沦落到使用这种手段。

3 forensic   

adj.法庭的，雄辩的

参考例句：

• The report included his interpretation of the forensic evidence.该报告包括他对法庭证据的诠释。
• The judge concluded the proceeding on 10:30 Am after one hour of forensic debate.经过近一个小时的法庭辩论后，法官于10时30分宣布休庭。

4 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。

5 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

6 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。

7 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。

8 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

9 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物