www射-国产免费一级-欧美福利-亚洲成人福利-成人一区在线观看-亚州成人

Global EditionASIA 中文雙語Fran?ais
World
Home / World / Africa

Elephant genome study offers surprises

China Daily | Updated: 2018-02-28 09:53
Share
Share - WeChat
A herd of adult and baby elephants walks in the dawn light with the highest mountain in Africa, Mount Kilimanjaro, in the background, in Amboseli National Park, southern Kenya, in 2012. [Photo/Agencies]

WASHINGTON - The most comprehensive elephant genome study ever conducted, covering seven living and extinct species, is offering some surprises about the family tree of the world's largest land animal while also settling a debate about Africa's elephants.

Researchers said on Monday that their research confirmed that the two types of African elephants, those inhabiting forests and those roaming savannas, are separate species that have lived in nearly complete isolation from one another for the past half million years despite their proximity.

They join the Asian elephant as the world's three existing elephant species.

The scientists sequenced the genomes of two African savanna elephants, two African forest elephants, two Asian elephants, two extinct so-called straight-tusked elephants, four extinct woolly mammoths, including two from North America and two from Siberia, one extinct Columbian mammoth and two extinct American mastodons. Mastodons are not classified as members of the elephant lineage but are cousins.

"I hope that this study can create an appreciation for the rich evolutionary history of elephants and emphasize the need for protecting the only three elephant species that still walk the planet today, who are all under imminent risk of extinction from poaching and habitat loss," said Harvard Medical School geneticist Eleftheria Palkopoulou, one of the researchers.

The research found multiple instances of gene flow - interbreeding - between different extinct elephant species, though this has all but stopped among today's elephants.

The straight-tusked elephants that once inhabited Europe and Asia - the largest of the species studied at up to 4 meters tall and 15 tons - are a case in point. The species turns out to be a hybrid with portions of its genome arising from an ancient African elephant, the woolly mammoth and the African forest elephants still alive today.

The scientists also found fresh evidence of interbreeding among the Ice Age Columbian and woolly mammoths, which crossed paths in locations where the more temperate regions of North America met the glaciers that then covered large parts of the continent.

The research was published in the Proceedings of the National Academy of Sciences.

Reuters - AFP

 

Most Viewed in 24 Hours
Top
BACK TO THE TOP
English
Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349
FOLLOW US
主站蜘蛛池模板: 日韩精品小视频 | 国产深夜福利 | 美国特级毛片 | 亚洲成人性视频 | 亚洲 欧美 成人日韩 | 亚洲第一中文 | 亚洲精品视频免费看 | 国产精品毛片一区二区三区 | 国产短视频精品一区二区三区 | 手机日韩理论片在线播放 | 国产a网 | 国产激情自拍 | 成人午夜兔费观看网站 | 久草免费在线播放 | 杨幂国产精品福利在线观看 | 亚洲欧美久久精品一区 | 一级毛片免费观看视频 | 国产精品久久久久久久久免费 | 三级全黄的全黄三级三级播放 | 亚洲精品午夜国产va久久成人 | 久久久久久综合七次郎 | 美女很黄很黄是免费的·无遮挡网站 | 最新亚洲情黄在线网站无广告 | 5x性区m免费毛片视频看看 | 久久精品免观看国产成人 | 美美女高清毛片视频黄的一免费 | 亚洲国产欧美视频 | 欧美成a| 日本aaaaa毛片动漫 | 久久一| 女人被男人躁得好爽免费文 | 午夜国产亚洲精品一区 | 精品国产免费观看 | 久久91视频| 麻豆国产96在线 | 日韩 | 色综合在 | 久草免费在线播放视频 | 顶级毛片在线手机免费看 | 国产主播精品福利19禁vip | 久久青草国产手机看片福利盒子 | 成人免费aaaaa毛片 |