在每一次物种大灭绝后，都有一次突然的进化爆发，因为会有新物种出现来填补灭绝创造的生态位。
Following each mass extinction, there is a sudden evolutionary burst as new species develop to fill the ecological niches opened by the event.
今天，我们正在见证第六次物种大灭绝，但与其它几次不同的是，目前生物多样性的丧失可以追溯到人类活动。
Today we are witnessing a sixth mass extinction, but unlike the others, the current loss of bio-diversity can be traced to human activity.
当然，人类正在引发地球历史上第6次物种大灭绝。
Of course, humanity is currently setting off the sixth mass extinction event in Earth's history.
物种大灭绝和不可恢复性是人类面临的最大环境威胁。
The mass extinction is the greatest environmental threat that human is facing.
地球的第六次物种大灭绝正在上演。一项新的研究发现，人类是其背后的推动力。
Earth's sixth mass extinction is already underway - and humans are the driving force behind it, according to a new study.
这潜在的第六次物种大灭绝独特之处在于，它主要是由单一一个物种的活动造成的。
This potential sixth great extinction is unique in that it is caused largely by the activities of a single species.
尽管不是五次物种大灭绝之一，二叠纪中期的物种灭绝依然被长期作为谜一般的事件受到重点关注。
Although not one of the "big five" mass extinctions, the mid-Permian extinction has long been considered an important, if puzzling, event.
即使在“物种大灭绝事件不会在一个可预测的周期中发生”这一观点上达成科学共识，我们也没有理由去怀疑太阳有一颗黑暗的伴星。
Even if the scientific consensus is that extinction events don't occur in a predictable cycle, there are now other reasons to suspect a dark companion to the Sun.
每隔1亿年左右，一颗更大的小行星可能导致物种大灭绝。大多数科学家相信一颗6英里直径的小行星在6500万年前使恐龙灭绝。
Once every 100 million years or so, an even larger asteroid may cause a mass extinction; most scientists believe a six-mile-wide asteroid doomed the dinosaurs 65 million years ago.
小型虾类不仅能独一无二的从数次物种大灭绝中存活下来，还能依靠雌雄同体之一进行繁殖，正因为如此，只要存在一只便可产生一个新的种群。
Not only are the shrimp unique for having survived several major extinctions, they also can have both male and female reproductive parts so just one can generate a new colony.
令人放心的研究结果表明，天文学家已经掌握了90％以上大型的小行星的空间位置，它们是一些可能导致地球表面生物物种大灭绝的，巨大的杀手行星。
The study reassuringly suggests that astronomers already know the location of more than 90 percent of the very largest asteroids — the huge planet-busters that could cause mass extinctions.
许多物种在地质上很短的时间间隔内灭绝的情况称为大灭绝。
Cases in which many species become extinct within a geologically short interval of time are called mass extinctions.
大约2.5亿年前，在地球历史上最严重的一系列大灭绝中，几乎所有的生命物种都消失了。
Roughly 250 million years ago, in the worst series of mass extinction in Earth's history, almost all species of life simply vanished.
随着二叠纪生命形式的衰退，它们达到了一个致命的临界点，物种最终走向了大灭绝。
As Permian life-forms declined, they reached a fatal threshold and species succumbed to mass extinction.
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。
The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.
地质记录中的其他几次大规模物种灭绝也被认为影响重大，但没有哪一次像白垩纪大灭绝那样夸张。
Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event.
根据自然资源保护者的重要回顾报告，地球正经历“第六次大灭绝事件”，因为疾病和人类活动正在令脆弱的物种遭受到灾难性打击。
Earth is experiencing its "sixth great extinction event" with disease and human activity taking a devastating toll on vulnerable species, according to a major review by conservationists.
化石证据显示，中小型动物比较大型物种更有可能在大灭绝中幸存下来。
Fossil evidence suggests that small and medium sized animals were more likely to survive the mass extinction than larger species.
从化石可以证明，在过去的五次大灭绝中，75%动物物种消失。
Evidence from fossils suggests that in the "Big Five" extinctions, at least 75 percent of all animal species were destroyed.
二叠纪-三叠纪最严重的大灭绝发生在两亿五千万年以前，杀死了所有物种的95%。
Permian-Triassic The worst mass extinction took place 250m years ago, killing 95% of all species.
闯入地球的小行星一般被认为是白垩-第三纪灭绝，即恐龙遭受大灭绝的主要原因之一。 那次毁灭性事件灭绝了地球上超过一半的物种，为哺乳动物成为地球上的首要物种扫清了道路。
The extinction was caused by a massive asteroid slamming into Earth at Chicxulub in Mexico.
真是一大讽刺：到处都有生物正在日趋灭绝，而我们甚至都无法期望对这些正游向湮没的大多数物种命名。
What an irony: that life is being extinguished everywhere, and we cannot even hope to name most of those creatures swimming towards oblivion.
地球正在经历他的第六次大灭绝事件，许多物种甚至在我们认知它之前就飞速地消逝了。
Earth is experiencing its sixth mass extinction event, species winking out of existence before we even know them.
物种周期性大灭绝的理论本身依然是备受争议的，需要更多的证据以便进一步地论证。
The theory of periodic extinctions itself is still debated, with many insisting that more proof is needed.
作为地球史上消亡物种排行第三的大灭绝，奥陶系-志留纪大灭绝有两个死亡高峰期，其中相隔数十万年时间。
The third largest extinction in Earth's history, the Ordovician-Silurian mass extinction had two peak dying times separated by hundreds of thousands of years.
虽然天体撞击的毁灭性不容置疑，但是没有证据表明彗星导致了地球物种周期性的大灭绝。
While there’s little doubt about the destructive power of cosmic impacts, there is no evidence that comets have periodically caused mass extinctions on our planet.
其它四次大灭绝对生物进化产生了巨大的影响，动物因此逐渐处于优势地位，但是，奥陶纪末期大灭绝发生前后，处于支配地位的动物物种没有发生变化。
Although the four other Big Five extinction events led to huge changes in which animals rose to prominence, the same animals that dominated before the end-Ordovician dominated afterward.
从另一个角度看，“巧妙之处在于，大灭绝事件就像重启按钮，通过它可以改变主宰地球的物种，”Conrad说。
Otherwise, "one neat thing about mass extinction events is that they're often reset buttons, where you change what dominates the globe, " Conrad said.
从另一个角度看，“巧妙之处在于，大灭绝事件就像重启按钮，通过它可以改变主宰地球的物种，”Conrad说。
Otherwise, "one neat thing about mass extinction events is that they're often reset buttons, where you change what dominates the globe, " Conrad said.
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