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Researchers at Sweden’s KTH Royal Institute of Technology say they have found further proof that the wolf ancestors of today’s dogs can be from southern East Asia -- findings that are contrary to theories placing the birth place in the Middle East. Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a new study released Nov. 23 confirms that an Asian region south of the Yangtze River was the principal and probably the only region where wolves were domesticated(驯化)by humans.
Research data show clearly that dogs are descended from wolves, but there’s never been scientific agreement on where in the world the domestication process began. “Our analysis of Y-chromosomal(染色体)DNA now confirms that wolves were first domesticated in Asia south of Yangtze River -- we call it the ASY region -- in southern China or Southeast Asia,” Savolainen says.
The Y data supports previous evidence from mitochondrial(线粒体)DNA. “Taken together, the two studies provide very strong evidence that dogs appeared first in the ASY region,” Savolainen says.
Archaeological data and a genetic study recently published in Nature suggest that dogs originate from the Middle East. But Savolainen rejects that view. “Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked,” he says.
Peter Savolainen and PhD student Mattias Oskarsson worked with Chinese colleagues to analyse DNA from male dogs around the world. Their study was published in the scientific journal Heredity.
Approximately half of the gene pool was universally shared everywhere in the world, while only the ASY region had the entire range of genetic diversity. “This shows that gene pools in all other regions of the world most probably originate from the ASY region,” Savolainen says.
“Our results confirm that Asia south of the Yangtze River was the most important -- and probably the only -- region for wolf domestication, and that a large number of wolves were domesticated,” says Savolainen.
In separate research published recently in Ecology and Evolution, Savolainen, PhD student Arman Ardalan and Iranian and Turkish scientists conducted a comprehensive study of mitochondrial DNA, with a particular focus on the Middle East. Because mitochondrial DNA is inherited only from the mother in most species, it is especially useful in studying evolutionary relationships.
“Since other studies have indicated that wolves were domesticated in the Middle East, we wanted to be sure nothing had been missed. We find no signs whatsoever that dogs originated there,” says Savolainen.
In their studies, the researchers also found minor genetic contributions from crossbreeding between dogs and wolves in other geographic regions, including the Middle East.
“This subsequent dog/wolf hybridisation(混合淡化技术)contributed only modestly to the dog gene pool,” Savolainen explains.
【小题1】What does Dr. Peter Savolainen believe?
A. Dogs’ ancestors came from the Middle East.
B. Wolves were probably first trained to work for humans in the ASY region.
C. Analysis of Y-chromosomal DNA should be combined with mitochondrial DNA.
D. Samples of the previous studies are enough to support the conclusion.
【小题2】We can learn from the passage that _______.
| A.there is a universal agreement on the place of first domestication |
| B.data from ASY may highlight where dogs came from |
| C.Dr. Savolainen’s research mainly focuses on the Middle East |
| D.the dog/wolf hybridization makes up most of the dog gene pool |
| A.It is only used in studying evolutionary relationships. |
| B.It alone can provide hard evidence for Savolainen’s research. |
| C.It is the most useful in finding out the birth place of dogs. |
| D.It comes from the mother of most animals and plants. |
请认真阅读下面对话,并根据各题所给首字母的提示,在答题卡上标有题号的横线上,写出一个英语单词的完整、正确形式、使对话通顺。
W: Where are you going to s___ your holiday this year, Bob?
M: We may go a___, but I’m not sure.
W: What do you mean?
M: Well, my wife’s talking about Egypt recently. She may want to go there. I’d like to go there, too.
W: Yes, it’s an interesting country to see.
M: But we can’t make up our m yet. You know, a round trip to Egypt c__ a lot.
W: But you may go by sea.
M: You’re right. It’s cheaper, isn’t it?
W: You may s____ at least half of the money if you go by ship.
M: But don’t you think it would t__ a long time and…
W: But you can enjoy the scene of the sea and the r_____ sun.
M: Yes, I’ll tell my wife.
W: You will definitely enjoy y_____, I’m sure.
M: Don’t be so sure. We may not go anywhere.
W: You always hesitate at everything.
M: It’s not my f____, you know. Wife always worries too much.
W: Like what?
M: Well… Who is going to look after the house? Who is going to look after the garden? And who is going to look after
the pets? We have these p___ every year. And in the end we stay at home and look after everything.
查看习题详情和答案>>Researchers at Sweden’s KTH Royal Institute of Technology say they have found further proof that the wolf ancestors of today’s dogs can be from southern East Asia -- findings that are contrary to theories placing the birth place in the Middle East. Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a new study released Nov. 23 confirms that an Asian region south of the Yangtze River was the principal and probably the only region where wolves were domesticated(驯化)by humans.
Research data show clearly that dogs are descended from wolves, but there’s never been scientific agreement on where in the world the domestication process began. “Our analysis of Y-chromosomal(染色体)DNA now confirms that wolves were first domesticated in Asia south of Yangtze River -- we call it the ASY region -- in southern China or Southeast Asia,” Savolainen says.
The Y data supports previous evidence from mitochondrial(线粒体)DNA. “Taken together, the two studies provide very strong evidence that dogs appeared first in the ASY region,” Savolainen says.
Archaeological data and a genetic study recently published in Nature suggest that dogs originate from the Middle East. But Savolainen rejects that view. “Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked,” he says.
Peter Savolainen and PhD student Mattias Oskarsson worked with Chinese colleagues to analyse DNA from male dogs around the world. Their study was published in the scientific journal Heredity.
Approximately half of the gene pool was universally shared everywhere in the world, while only the ASY region had the entire range of genetic diversity. “This shows that gene pools in all other regions of the world most probably originate from the ASY region,” Savolainen says.
“Our results confirm that Asia south of the Yangtze River was the most important -- and probably the only -- region for wolf domestication, and that a large number of wolves were domesticated,” says Savolainen.
In separate research published recently in Ecology and Evolution, Savolainen, PhD student Arman Ardalan and Iranian and Turkish scientists conducted a comprehensive study of mitochondrial DNA, with a particular focus on the Middle East. Because mitochondrial DNA is inherited only from the mother in most species, it is especially useful in studying evolutionary relationships.
“Since other studies have indicated that wolves were domesticated in the Middle East, we wanted to be sure nothing had been missed. We find no signs whatsoever that dogs originated there,” says Savolainen.
In their studies, the researchers also found minor genetic contributions from crossbreeding between dogs and wolves in other geographic regions, including the Middle East.
“This subsequent dog/wolf hybridisation(混合淡化技术)contributed only modestly to the dog gene pool,” Savolainen explains.
1.What does Dr. Peter Savolainen believe?
A. Dogs’ ancestors came from the Middle East.
B. Wolves were probably first trained to work for humans in the ASY region.
C. Analysis of Y-chromosomal DNA should be combined with mitochondrial DNA.
D. Samples of the previous studies are enough to support the conclusion.
2.We can learn from the passage that _______.
A.there is a universal agreement on the place of first domestication
B.data from ASY may highlight where dogs came from
C.Dr. Savolainen’s research mainly focuses on the Middle East
D.the dog/wolf hybridization makes up most of the dog gene pool
3.What is special about mitochondrial DNA?
A.It is only used in studying evolutionary relationships.
B.It alone can provide hard evidence for Savolainen’s research.
C.It is the most useful in finding out the birth place of dogs.
D.It comes from the mother of most animals and plants.
查看习题详情和答案>>
On the New York set of the film Hide and Seek, ten-year-old Dakota Fanning spends her time playing a deeply disturbed girl who deals with her mother's suicide (自杀) by creating an imaginary friend, who may not frighten her family.
Today, though, she has the day off. "This week I only worked two days,"says Fanning, sitting in a sofa in her hotel's library, "but I get bored when I'm not working. Especially because it's cold here and I can't do anything, you know? So, I've been knitting (编织) --- all day, every day."The actress, who's held her own opposite Oscar winners such as Sean Penn and Denzel Washington, recently mastered the fine art of scarves (围巾). Though she's about ready to move on to hats, she first plans to make a souvenir (纪念品) scarf for Robert De Niro, who plays her father in the film. "He's the nicest guy you'd ever meet in your entire life,"she says, her voice dropping to a whisper. "I would make him a brown one.”
Like any other fifth-grader, Fanning spends several hours a day going to school. In addition to her personal trailer (活动住房) --- which is kept well-supplied with hot chocolate packets, lemon Gatorade, and a TV that doesn't always work --- she has another trailer where her teacher, Jan, conducts classes in history, spelling, reading, math, science and health. "We have this big board where we have a calendar (日历),"Fanning says. "When we were here in January, I wrote the calendar in all blue. February was red, and March was green.”
On this particular morning, she had a spelling test. "There was a topic for each of the word lists,"she says, sitting on her knees. "This one was flowers --- they were all names like oxygen, carbon dioxide, chrysanthemum (菊花)..."Chrysanthemum? "Well, they didn't make me spell that one. They just had me fill in the ‘e'. But I can spell it: c-h-r-y-s-a-n-t-h-e-m-u-m.”
Which of the following is NOT true?
A. Dakota Fanning is a young gifted actress.
B. Dakota Fanning is a lonely orphan.
C. Dakota Fanning is a creative pupil.
D. Dakota Fanning has many interests.
Dakota Fanning has to knit all day in order to _____.
A. kill time B. make money C. master a skill D. make a scarf for her boyfriend
By saying that "He's the nicest guy you'd ever meet in your entire life”, Dakota Fanning really means that _____.
A. she is the daughter of Robert De Niro
B. she has fallen in love with Robert De Niro
C. she is in love with Robert De Niro
D. she admires Robert De Niro very much
What would be the best title for the text?
A. Dakota Fanning's Role
B. Dakota Fanning's Knitting Art
C. Dakota Fanning's Day Off
D. Dakota Fanning's Spelling Test
查看习题详情和答案>>请认真阅读下面对话,并根据各题所给首字母的提示,在答题卡上标有题号的横线上,写出一个英语单词的完整、正确形式、使对话通顺。
W: Where are you going to s__1._ your holiday this year, Bob?
M: We may go a__2._, but I’m not sure.
W: What do you mean?
M: Well, my wife’s talking about Egypt recently. She may want to go there. I’d like to go there, too.
W: Yes, it’s an interesting country to see.
M: But we can’t make up our m3.yet. You know, a round trip to Egypt c__4. a lot.
W: But you may go by sea.
M: You’re right. It’s cheaper, isn’t it?
W: You may s__5.__ at least half of the money if you go by ship.
M: But don’t you think it would t_6._ a long time and…
W: But you can enjoy the scene of the sea and the r___7.__ sun.
M: Yes, I’ll tell my wife.
W: You will definitely enjoy y__8.___, I’m sure.
M: Don’t be so sure. We may not go anywhere.
W: You always hesitate at everything.
M: It’s not my f__9.__, you know. Wife always worries too much.
W: Like what?
M: Well… Who is going to look after the house? Who is going to look after the garden? And who is going to look after
the pets? We have these p_10.__ every year. And in the end we stay at home and look after everything.
查看习题详情和答案>>