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Species Split When Mountains Rise 生脉隆起导致生物多样化

The tropics are well known for their biodiversity. But another hotspot? Mountains. Like the Hengduan Mountains, in south-central China.

热带地区因为其生物多样性而为大家所知.但是它的另外一个热点呢?山脉.例如在中国中南部的横断山脉.

"It'll look very much like this kind of familiar temperate¹ alpine² system, but the plant diversity there is off the charts."

这看起来就像熟悉的温带高山,但是在这个图表上没有生物的多样性.

Rick Ree is associate curator of botany at the Field Museum in Chicago.

瑞克瑞是芝加哥菲尔德博物馆植物学部门的副馆长.

These mountains harbor a third of all China's plant species. And one hypothesis for mountain biodiversity is that mountain uplift creates new climates and habitats. "You'll see coniferous forests, limestone³ and granite⁴ outcrops with glaciers⁵ and rivers and alpine meadows."

这些山脉孕育了中国1/3的植物物种。其中对于山脉中生物多样性的假设就是，隆起的山脉创造了新的气候和栖息地。“你会看到原始森林、石灰岩以及花岗岩，冰川河流以及高山草甸。”

Plants take advantage of the new niches⁶, and diversify⁷.

植物利用这里的新领域，并多元化。

Now Ree and his colleague, Yaowu Xing, have evidence supporting the idea for connection between mountain building and biodiversity. They used DNA⁸ data to build an evolutionary⁹ tree of plants in the Hengduan. Then they calibrated¹⁰ the tree with fossil data. And they saw an explosion in diversification¹¹ around eight million years ago—right when uplift occurred. The results are in the Proceedings¹² of the National Academy of Sciences.

现在，瑞和同事邢晓武已经有证据支持造山和生物多样性之间的关系。他们利用DNA数据建立了横断山植物的进化图谱。之后，利用化石数据来校对这些树木。他们发现在八万年前这里的生物多样性激增——而这正是山脉隆起的时间。该研究结果发表在《美国国家科学院院刊》杂志上。

So if new microclimates create new opportunities for diversification: what about global climate change? "If we look back on the history of life, one very striking pattern that we can see is that evolutionary diversification is pretty strongly associated with changing conditions. The flipside to change is that some species go extinct and some species diversify. So we're faced with both prospects¹³ I think going forward."

如果，新的气候为生物多样性创造了新的机遇：那么全球变化呢?我们回顾生命的历史，会发现一个惊人的模式，那就是生物多样性和环境的变化有着密切的联系。变化的一方面是一些物种的灭绝，而另一些物种的多样化。所以，我认为在未来我们面对的是双面的前景。