新东方在线网络课堂 托福 新东方在线 > 托福 > 托福精选 > 正文

科学美国人60秒:大迁徙导致遗传多样性-托福听力下载

2016-12-01 17:14:45 来源:科学美国人60秒托福资料下载

点击查看>>科学美国人60秒音频:大迁徙导致遗传多样性

  科学美国人60秒中英文翻译:大迁徙导致遗传多样性

  科学美国人60秒英文文本

  This is Scientific American — 60-Second Science. I'm Erika Beras.

  Got a minute?

  It's called the Great Migration—the journey of some six million African-Americans from the rural south to northern and western cities between 1910 and 1970. The cultural impact of the Great Migration has been well documented. But researchers have also started to look at its genetic implications. The most recent study finds that the migration had a significant effect on genomic diversity across the nation. That work is in the journal PLOS Genetics.

  To estimate patterns of ancestry, researchers analyzed genetic data from nearly four thousand African-Americans who had participated in three medical studies.

  Their findings confirmed historical records—genetic evidence showed that female slaves often gave birth to children fathered by white slaveowners. The genetic analysis found that 82.1 percent of the average African-American's ancestors came from Africa, while 16.7 percent were Europeans and 1.2 percent were Native American.

  The team also could date when particular genes entered the mix. Native American genes were introduced into the typical African-American genome in the early 1600's. Genes from Europeans were for the most part introduced in the decades before and during the Civil War.

  Researchers also found those still living in the southern United States have a greater percentage of African ancestry than those in the north or west. And European-Americans who now live in the south are more genetically similar to African-Americans in the north and west than they are to African-Americans currently living in the South—because Blacks with a greater percentage of European ancestry were more likely to move, especially early in the migration's history.

  The analysis has implications for medical research and treatment. Most of the people in studies linking genes and disease have been white, thus potentially leaving gaps in medical information specific to other races. Filling in those gaps, along with better access to medical care, could help reduce the disparity in health experienced by many minority communities.

  Thanks for the minute for Scientific American — 60-Second Science Science. I'm Erika Beras.

  中文翻译请点击下一页

本文关键字: 科学美国人60秒 科学60秒下载 托福听力

为你特别匹配的托福超值课程,快速提分先人一步!
  • 【直播课程】托福考前10天,如何才能自救

    【直播课程】托福考前10天,如何才能自救

    适合人群:备战托福的筒子们!!!

    课时:8 课程有回放~

    查看详情
  • 大学生旗舰直达冲100分

    【知心托福】大学生旗舰直达冲100分

    适合人群:托福目标分数100!!!

    课程特色:推送补充相应知识点,有效提升学习效率。

    查看详情
  • 【21天冲分】 21天直冲托福100+

    【21天冲分】 托福2018年8月临考急训25人班

    适合人群:参加过托福考试或基础段的学习,距离最新考试仅剩1个月时间,急需短期内快速高效冲分的考生。

    特点:全科直播24小时

    查看详情
  • TOEFL8月早练团

    【早练团】TOEFL8月早练团

    课程特色:高能学习的正确打开方式,早练早提分!

    课时:28课时(每天0.5小时,5月共上课28天)

    查看详情
  • 大学生旗舰直达班 (冲110分)

    【知心托福】大学生旗舰直达班 (冲110分)

    适合人群:托福目标分数110分!

    课时:343

    查看详情

托福人气课程推荐全部课程

最受欢迎课程 知心托福大学生旗舰直达班(冲110分) ¥8280 免费试听
知心托福中学生旗舰直达班(冲110分) ¥8280 免费试听
知心托福精品直达班(冲110分) ¥5880 免费试听
单项突破 阅读口语听力写作
托福入门 词汇语音精听三科联报
直播课堂 考前预测
致赢一对一 临考冲刺临考强化短期集训强化冲分低起点冲分零起点托管冲分
更多托福课程
新东方23年教学经验沉淀
托福考生必修课
全球首发ETS独家授权TPO全真模考精准预测
查看详情

课程试听换一换

  • 知心托福 大学生旗舰直达班 (冲110分)

    ¥8280

  • 知心托福 直达班(冲110分)

    ¥4380

  • 知心托福 精品直达班(冲110分)

    ¥5880

  • 知心托福 直达班(冲100分)

    ¥4080

  • 知心托福 精品直达班(冲100分)

    ¥5680

  • 知心托福 大学生旗舰直达班 (冲100分)

    ¥7980

  • 新东方托福全名师21天魔鬼急训冲分【8月...

    ¥7499

  • 知心托福 中学生旗舰直达班 (冲110分)

    ¥8280

分享到:

相关推荐

交流 • 下载

精品课限量免费领

  • 托福名师直播公益课
  • 北美中学直播课程
  • 托福听力备考全攻略
  • 世界大学排名榜(全球大学排名)
  • 最新美国大学排名

提分历程更多>>

实用 • 工具

托福课程排行榜本周本月

托福公开课更多>>

新东方在线托福名师宣传片 w 03分32秒
1 新东方在线托福名师宣传片
新东方在线知心托福介绍说明【热】 w 04分14秒
2 新东方在线知心托福介绍说明【热】
新东方在线唐悦宁:托福词汇遗忘规律 w 07分34秒
3 新东方在线唐悦宁:托福词汇遗忘规律
新东方在线唐悦宁:词根词缀记忆法 w 04分42秒
4 新东方在线唐悦宁:词根词缀记忆法
新东方在线唐悦宁:托福听力基础预备 w 03分30秒
5 新东方在线唐悦宁:托福听力基础预备

推荐阅读