基因分析显示长颈鹿有四大种类
文章来源:未知 文章作者:enread 发布时间:2016-12-10 08:23 字体: [ ]  进入论坛
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Up until now, scientists had only recognized a single species of giraffe made up of several subspecies. But, according to the most inclusive genetic1 analysis of giraffe relationships to date, giraffes actually aren't one species, but four. For comparison, the genetic differences among giraffe species are at least as great as those between polar and brown bears. The unexpected findings reported in the Cell Press journal Current Biology on September 8 highlight the urgent need for further study of the four genetically2 isolated3 species and for greater conservation efforts for the world's tallest mammal, the researchers say.
 
"We were extremely surprised, because the morphological and coat pattern differences between giraffe are limited," says Axel Janke, a geneticist at the Senckenberg Biodiversity and Climate Research Centre and Goethe University in Germany. Giraffes are also assumed to have similar ecological4 requirements across their range, he added, "but no one really knows, because this megafauna has been largely overlooked by science." 
 
Giraffes are in dramatic decline across their range in Africa. Their numbers have dropped substantially over the last three decades, from more than 150,000 individuals to fewer than 100,000. Despite that, the researchers say that there has been relatively5 little research done on giraffes in comparison to other large animals, such as elephants, rhinoceroses6, gorillas7, and lions.
 
About five years ago, Julian Fennessy of Giraffe Conservation Foundation in Namibia approached Janke to ask for help with genetic testing of the giraffe. Fennessy wanted to know how similar (or not) giraffes living in different parts of Africa were to each other, whether past translocations of giraffe individuals had inadvertently "mixed" different species or subspecies, and, if so, what should be done in future translocations of giraffes into parks or other protected areas. 
 
In the new study, Janke and his research group examined the DNA8 evidence taken from skin biopsies of 190 giraffes collected by Fennessy and team all across Africa, including regions of civil unrest. The extensive sampling includes populations from all nine previously9 recognized giraffe subspecies.


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1 genetic PgIxp     
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。
2 genetically Lgixo     
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
3 isolated bqmzTd     
adj.与世隔绝的
参考例句:
  • His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
  • Patients with the disease should be isolated. 这种病的患者应予以隔离。
4 ecological IrRxX     
adj.生态的,生态学的
参考例句:
  • The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
  • Each animal has its ecological niche.每种动物都有自己的生态位.
5 relatively bkqzS3     
adv.比较...地,相对地
参考例句:
  • The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
  • The operation was relatively painless.手术相对来说不痛。
6 rhinoceroses 75b06ff1c3ad4bf5e454140a332dce7a     
n.钱,钞票( rhino的名词复数 );犀牛(=rhinoceros);犀牛( rhinoceros的名词复数 );脸皮和犀牛皮一样厚
参考例句:
  • Rhinoceroses and dragons for once will let us walk in peace. 犀牛与龙安歇,让我们能平静地行走。 来自互联网
  • Although the rhinoceroses are very heavy, they can run very fast. 犀牛虽然体型笨重,但仍能以相当快的速度行走或奔跑。 来自互联网
7 gorillas a04bd21e2b9b42b0d71bbb65c0c6d365     
n.大猩猩( gorilla的名词复数 );暴徒,打手
参考例句:
  • the similitude between humans and gorillas 人类和大猩猩的相像
  • Each family of gorillas is led by a great silverbacked patriarch. 每个大星星家族都由一个魁梧的、长着银色被毛的族长带领着。 来自《简明英汉词典》
8 DNA 4u3z1l     
(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。
9 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
TAG标签: species animals giraffe
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