About 30,000 species go extinct annually.
大約每年有30000種物種走向滅絕。
There is little doubt left in the minds of professional biologists that Earth is
currently faced with a mounting loss of species that threatens to rival the five
great mass extinctions of the geological past.
在生物學專家心中都有壹個小小的疑問，地球是否在面臨著可能媲美過去五大物種滅絕的另
壹次不斷增加的物種滅絕。
As long ago as 1993, Harvard biologist E.O. Wilson estimated that Earth is
currently losing something on the order of 30,000 species per year -- which
breaks down to the even more daunting statistic of some three species per hour.
早在1993年，哈佛壹名生物學家，E.O. Wilson就預測地球物種正在以每年30000種的速度消
失, 而這種令人心悸的預測則被更為恐怖的每小時3種的統計結果結束了.
Some biologists have begun to feel that this biodiversity crisis -- this "Sixth
Extinction" -- is even more severe, and more imminent, than Wilson had supposed.
The previous mass extinctions were due to natural causes.
壹些生物學家已經開始察覺到生物多樣性的危機了. Wilson預測說這次的第六次物種滅絕,
比以往五次更為嚴重,更為緊迫。前幾次大量物種滅絕的發生，只是因為自然原因。
Extinction in the past
過去的幾次大量物種滅絕
The major global biotic turnovers were all caused by physical events that lay
outside the normal climatic and other physical disturbances which species, and
entire ecosystems, experience and survive. What caused them?
過去的幾次生物界翻天覆地的變化，原因都不外乎正常的天氣還有其他的物理因素幹擾這些
物理因素，而整個生態系統都安然度過了。這些都是怎樣發生的呢？
* First major extinction (c. 440 mya): Climate change (relatively severe and
sudden global cooling) seems to have been at work at the first of these-the end
-Ordovician mass extinction that caused such pronounced change in marine life
(little or no life existed on land at that time). 25% of families lost (a family
may consist of a few to thousands of species).
第壹次大量物種滅絕（c.440 mya）:較為嚴重的突然全球變冷似乎先發生，然後就有了
引起海洋物種顯著變化的後奧陶紀的大量物種滅絕（當時很少或者根本沒有生物在大路上生
存），大約25%的物種科目消失了（壹個物種科目可能含有幾十到上千的物種）。
* Second major extinction (c. 370 mya): The next such event, near the end of
the Devonian Period, may or may not have been the result of global climate
change. 19% of families lost.
第二次大量物種滅絕（c. 370 mya）：第二次類似的事件發生在大概泥盆紀結束的時候
，尚未清楚是否由於全球氣候的變化。這次有19%的物種科目消失了。
* Third major Extinction (c. 245 mya): Scenarios explaining what happened at
the greatest mass extinction event of them all (so far, at least!) at the end of
the Permian Period have been complex amalgams of climate change perhaps rooted
in plate tectonics movements. Very recently, however, evidence suggests that a
bolide impact similar to the end-Cretaceous event may have been the cause. 54%
of families lost.
第三次大量物種滅絕（c. 245 mya）:地質構造論中二叠紀發生的大範圍地殼運動和氣
候的復雜多變可以解釋這次起碼到現在為止是最大規模的大量物種滅絕。但在最近，又有證
據說類似於後白堊紀的流星事件可能是這次物種滅絕的主要原因。這次54%的物種科目被滅
絕了。
* Fourth major extinction (c. 210 mya): The event at the end of the Triassic
Period, shortly after dinosaurs and mammals had first evolved, also remains
difficult to pin down in terms of precise causes. 23% of families lost.
第四次大量物種滅絕（c.210 mya）:這次大量物種滅絕發生在發生在三疊紀後期，在進
化出恐龍和哺乳動物之後不久。這次物種滅絕很難精確確定出原因。23%的物種科目消失了
* Fifth major extinction (c. 65 mya): Most famous, perhaps, was the most
recent of these events at the end-Cretaceous. It wiped out the remaining
terrestrial dinosaurs and marine ammonites, as well as many other species across
the phylogenetic spectrum, in all habitats sampled from the fossil record.
Consensus has emerged in the past decade that this event was caused by one
(possibly multiple) collisions between Earth and an extraterrestrial bolide
(probably cometary). Some geologists, however, point to the great volcanic event
that produced the Deccan traps of India as part of the chain of physical events
that disrupted ecosystems so severely that many species on land and sea rapidly
succumbed to extinction. 17% of families lost.
第五次大量物種滅絕(c. 65 mya):物種滅絕中最為著名的可能莫過於距離現在最近的
在白堊紀末發生的第五次物種滅絕. 根據對化石的研究發現,在這次物種滅絕中,陸地恐龍和
鸚鵡螺都完全消失. 有著同樣命運的還有許多物種譜中的生物. 在過去十年中,大家都認為
這次物種滅絕的原因在於壹次(也有可能是多次)地球與宇宙流星(很有可能是彗星)的相撞.
但壹些地質學家持不同意見。他們把原因歸結於產生了印度德幹traps（陷阱？）的火山運
動而造成的生態系統的劇烈變動，最終使陸地上和海裏的許多生物迅速走向滅絕。
The current mass extinction is caused by humans.
現在我們面臨的大量物種滅絕是人為因素造成的。
How is the Sixth Extinction different from previous events?
第六次大量物種滅絕與之前有什麽不同呢？
At first glance, the physically caused extinction events of the past might seem
to have little or nothing to tell us about the current Sixth Extinction, which
is a patently human-caused event. For there is little doubt that humans are the
direct cause of ecosystem stress and species destruction in the modern world
through such activities as:
初步來看，過去五次大量物種滅絕對現在第六次認為造成的物種滅絕沒有任何可借鑒意義，
因為毫無疑問人類造成了如下幾種情況，給生態系統造成了很大壓力，給物種帶來了滅絕：
* transformation of the landscape
地貌的改變
* overexploitation of species
物種資源的過度開發
* pollution
汙染
* the introduction of alien species
帶來了外來物種
And because Homo sapiens is clearly a species of animal (however behaviorally
and ecologically peculiar an animal), the Sixth Extinction would seem to be the
first recorded global extinction event that has a biotic, rather than a
physical, cause.
同樣由於智人很明顯是動物的壹員（雖然行為和外貌上不很像動物），第六次物種滅絕似乎
是有史以來第壹次由生物而不是物理環境變化引起的。
We are bringing about massive changes in the environment.
我們給環境帶來了劇烈的變化。
Yet, upon further reflection, human impact on the planet is a direct analogue of
the Cretaceous cometary collision. Sixty-five million years ago that
extraterrestrial impact -- through its sheer explosive power, followed
immediately by its injections of so much debris into the upper reaches of the
atmosphere that global temperatures plummeted and, most critically,
photosynthesis was severely inhibited -- wreaked havoc on the living systems of
Earth. That is precisely what human beings are doing to the planet right now:
humans are causing vast physical changes on the planet.
Humans began disrupting the environment as soon as they appeared on Earth.
然而進壹步的說，人類對於地球的影響，完全相當於白堊紀的彗星撞擊。彗星帶來了爆炸性
的力量，緊接著把碎片帶到大氣上層，引起了全球氣候降低，還有最重要的，極大地降低了
光合作用，就像是對地球生態系統的憤怒轟炸壹樣。這完全和現在人類正在對這顆行星做的
壹樣：人類正在給這顆行星的物理環境帶來巨大的改變，而這種改變，自從人類出現便已經
開始了。
What is the Sixth Extinction?
什麽是第六次大量物種滅絕？
We can divide the Sixth Extinction into two discrete phases:
我們可以把第六次大量物種滅絕分為兩段
* Phase One began when the first modern humans began to disperse to
different parts of the world about 100,000 years ago.
第壹階段開始於100，000年前現代人類分散到世界各地
* Phase Two began about 10,000 years ago when humans turned to agriculture.
第二階段開始與10，000年前人類開始了農業勞動
先翻譯到這裏。。。有空我會接著翻。。。
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