At one time, ecologists believed that species diversity made ecosystems stable.

生态学家曾一度认为，物种多样性使生态系统变得稳定。

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This ancestral species might have evolved at a time when the islands were connected.

这种祖先物种可能是在岛屿相连的时候进化而来的。

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The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.

二叠纪大灭绝事件比其他大灭绝事件受到的关注要少得多，因为那时灭绝的大多是我们不熟悉的物种。

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Lead author Beth Polidoro works for the Global Marine Species Assessment Unit, based at Old Dominion University in Richmond,Virginia.

VOA: special.2010.04.20

Those animals that you produce are called transgenic animals because they're expressing, usually at high levels, a transgene or a gene that's not normally present in their species.

那么这些小鼠就称为转基因动物,因为转基因动物,通常能高效地,表达转基因,即一个通常不存在于该物种的基因

耶鲁公开课 - 生物医学工程探索课程节选

At depths of nearly four hundred meters, the researchers found the oldest examples of two species of coral.

VOA: special.2009.05.12

Biodiversity impacts can occur at the species level and at the ecosystem level.

FORBES: Operationalizing the Precautionary Principle for Biodiversity

From there, cameraman Eduardo Aragona and I drove two hours on a bumpy, red-dirt road to arrive at the Estancia Rincon del Socorro, the traditional Argentine ranch that the Tompkins operate, and where guests from around the globe come to get up-close looks at rare species of capybara, caiman, deer and scores of birds.

CNN: The philanthropists 'paying rent' to planet Earth in Argentina

And a back-of-the-envelope calculation based on the 1.8m sorts of organism recognised so far as species under the Linnaean system, on the rate at which new species are being discovered and on such ecological matters as the average number of parasites (themselves new species) that each free-living species harbours, suggests the final total may be around 30m.

ECONOMIST: Biodiversity