Scientists discover new species all the time—on the order of 15,000 a year. One of the latest additions to the tree of life is a new type of leopard frog. Which might sound unremarkable, except for where it was found: New York City.
科学家时时刻刻在发现新物种——每年大约能发现15000种。这次发现的是一种新型豹蛙。除了这种青蛙被发现的地方纽约市引人瞩目之外,它们似乎毫不起眼。
But how does a frog go unnoticed in the Big Apple? Well even experts have a hard time telling this new species from its northern and southern cousins on looks alone. But the new guy has a different croak, which raised ecologists' suspicions. So they tracked down four leopard frog populations with the unique call—including one within view of the Statue of Liberty—and took DNA samples.
但是,为什么青蛙在大苹果城会被忽视呢?单就外形而言,即使专家也很难指出这个新物种同它的北部和南部的堂兄弟之间到底存在什么区别。但是这个新家伙叫声很奇特,这令生态学家很疑惑。因此,他们研究了四种具有不同叫声的青蛙种类——其中包括自由女神区域的青蛙种类,并提取了它们的DNA样本。
As they suspected, the odd croakers weren't southern or northern leopard frogs, or even a mix. They had a genetic ancestry of their own—earning them new species status. Those results appear in the journal Molecular Phylogenetics and Evolution.
正如他们所怀疑的那样,这种青蛙既不是南方豹蛙也不是北方豹蛙——甚至也不是二者的结合体。它们有自己的遗传祖先——给予它们独有的物种特征。这项研究成果发表在《分子系统发育和进化》杂志上。
The frogs are tough New Yorkers—the center of their range appears to be Yankee Stadium. But the researchers say that the urban amphibians face threats like pesticides and infectious diseases. Not to mention real-life games of Frogger.
这群青蛙是艰难生活的纽约客——他们活动区域的中心似乎是在洋基球场。但研究人员说,这种城市两栖动物面临着诸如农药和传染病的威胁,更别说现实版青蛙过河游戏中的种种危险了。
来源:可可英语 http://www.kekenet.com/broadcast/201204/176288.shtml