ࡱ> 463)` R!bjbj2"{{ $ $ $ $ 0  *H H H H H H H H        $hj^A Q H H A H H  "H H    H < @XI$ / d  0   8 $H r Z \ WH H H A A H H H  Where Do We Come From? bN0R^egT̑ From VOA Learning English, this is Science in the News. ُ̑/fVKNbayf[ebS0 Would you like to know where your ancestors came from? British and American scientists may have found answers for you. They have developed a new algorithm to study deoxyribonucleic acid, also known as DNA -- the building blocks of life. `O`wS`OvVyHQegT̑TVTVvyf[[S]~:N`O~b0RT{Hh0NN]~_SQNyev{legxvz1'l8h|8hx _NyDNA  u}TvWw0 The algorithm is a step-by-step operation for solving problems. It is called  Geographic Population Structure, or GPS. The report was prepared by researchers from the University of Sheffield in England, and the University of Southern California. It was published in the journal Nature Communications. 勗{l/fNy㉳QvekЏ{ y:N 0WtNS~g {yGPS0ُNxvzbJT/f1uV"\_'Yf[TWSR]'Yf[vxvzNXT[bv Sh(W 06q 0Bg_ N0 The researchers say GPS can find a village or tribe where genes became mixed as far back as 1,000 years ago, during population movements or invasions. At such times, people from groups that were separated earlier came together and had children. xvzNXTy GPSSN~b0R܏(W1000Yt^MRvQg^b=̑N (WNSAmRTOeuǏ z-N NNvWV/fNNHN0We_YmTv0(W*NeP eg N TSOvNN eevy_TꁄvSO u;m(WNw v^NuNi[P[0 The British and American scientists tested their algorithm by studying genetic information from 200 individuals. The people were from 10 villages on the Italian island of Sardinia. GPS correctly placed 25 percent of the people directly in their villages. Most of the other individuals were placed within 50kilometers of their villages. A test involving more than 20 islands in the Pacific Ocean produced similar results. In all, 98 percent of the information proved correct. ,@B > @ :<$R24   Z!~!!!οv hxLhxLKHOJQJ^JaJhxLhFOJQJaJo(hxLOJQJaJo(UhxLhxLCJOJQJaJo(hxLCJOJQJaJo(hxLhxLCJOJQJaJ"hxLhxL5CJOJQJaJo(hxL5CJOJQJaJo(hxLhxL5CJOJQJaJ!.B @ <&S4   Z!!!gdxL$a$gdxL!VTVvyf[[Ǐxvz200*NNvWVOo` hKmNNNv{l0ُNNega'Y)RdN\v10*NQg^0GPS{lvccknxFd>eN;`Npe-N25%vNvMOn0'YYpevvQN*NSO>en(WݍyNNQg^50lQ̑NQv0W:SVQ0(W*Ys^ m20Y*N\vKmՋ_NNuN{|