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  • 生物多样性 - 高级

    biodiversity

    What is biodiversity?
    ::什么是生物多样性?

    How many exist? We don't really know for sure. But all those species together, from the smallest , the deadliest , the most bizarre , the prettiest plant, and the biggest mammal , compile the diversity of life, or biodiversity.
    ::有多少植物存在?我们并不确定。但所有这些物种,从最小的,最致命的,最奇异的,最漂亮的植物, 和最大的哺乳动物, 汇集了生命的多样性,或生物多样性。

    What is Biodiversity?
    ::什么是生物多样性?

    Humans, like all species, depend on certain natural resources for survival. We depend on land and soils to grow crops, which transform solar energy into food . We use the Earth’s freshwater lakes, rivers, and groundwater for drinking. We rely on the atmosphere to provide us with oxygen and to shield us from radiation. We rely on Earth’s biodiversity for food, clothing, and medicines. We utilize all of the “basic four” (biodiversity, land, , air) for recycling of nutrients and disposal of waste. Natural , as Odum suggests, provide services for all species: they maintain soil , renew the atmosphere, replenish freshwater supplies, dispose of wastes, and recycle nutrients. In our dependence on these services, we are like all other species.
    ::人类和所有物种一样,依赖某些自然资源生存。我们依靠土地和土壤种植作物,将太阳能转化为食物;我们利用地球淡水湖泊、河流和地下水饮用;我们依靠大气层为我们提供氧气,保护我们免受辐射;我们依靠地球生物多样性提供食物、衣物和药品;我们利用所有“基本四”(生物多样性、土地、空气)回收养分和废物处理。正如奥杜姆所言,自然为所有物种提供服务:它们维持土壤、更新大气层、补充淡水供应、处理废物和回收养分。 在依赖这些服务的过程中,我们与其他物种一样,我们与所有其他物种一样,都依赖这些服务。

    Yet in many ways, we do not behave like other species. We supplement food and energy with fossil fuel energy. We harvest natural resources to exhaustion, and produce waste beyond levels that the Earth can process. We alter biodiversity, land, water, air and fossil fuels beyond nature’s ability to repair. As you learned in your study of biology , our population has grown beyond Earth’s carrying capacity , compounding problems of resource use and waste disposal. Only recently have we learned to appreciate the full value of these resources – and the potential for harm from our own activities. Our economics have not caught up to our relatively new understanding: we do not yet pay the costs of maintaining all of “nature’s services.”
    ::然而,在许多方面,我们的行为不像其他物种。 我们用化石燃料能源来补充食物和能源。 我们收获自然资源以耗尽,产生超过地球所能处理的废物。 我们改变生物多样性、土地、水、空气和化石燃料,而超出了自然的修复能力。 正如你在生物学研究中了解到的,我们的人口已经超出了地球的承载能力,加剧了资源使用和废物处理问题。 直到最近,我们才学会了如何理解这些资源的全部价值 — — 以及我们自己活动的潜在危害。 我们的经济还没有赶上我们较新的理解:我们还没有支付维持所有“自然服务”的成本。

    This lesson will explore biodiversity – the “millions of organisms and hundreds of processes - operating to maintain a livable environment.” The topic is timely, critical, and colorful: you will encounter warnings of a Biodiversity Crisis and the Sixth Extinction , and species identified as “an Elvis taxon” or “a Lazarus taxon .” More importantly, by the end of your study, you will have some tools you can use in your daily life to help protect the great diversity of Earth’s life.
    ::这一教训将探索生物多样性 — — “百万生物体和数百种过程 — — 用于维持一个可居住环境 ” 。 这一主题是及时、关键和多姿多彩的:你将遇到生物多样性危机和第六次灭绝的警告,以及被确定为“猫王税”或“拉扎鲁斯税 ” 的物种。 更重要的是,在你的研究结束时,你将有一些工具可以在日常生活中用来帮助保护地球生命的巨大多样性。

    Biodiversity
    ::生物多样性生物多样性生物多样性

    “The first rule of intelligent tinkering is to save all the pieces.” --attributed to Aldo Leopold, but probably a shortened version of: "To save every cog and wheel is the first precaution of intelligent tinkering." - Aldo Leopold, Round River: from the Journals of Aldo Leopold , 1953
    ::“智慧修补的第一规则是保存所有碎片。” -- -- 由Aldo Leopold引用,但可能有一个简写版本:“拯救每一个齿轮和轮子是智能修补的第一预防措施。” - Aldo Leopold,Round River:摘自《阿尔多·利奥波德日报》,1953年。

    What are the “cogs” and “wheels” of life?
    ::生命的“阴道”和“轮子”是什么?

    Although the concept of biodiversity did not become a vital component of biology and political science until nearly 40 years after Aldo Leopold’s death in 1948, Leopold – often considered the father of modern ecology - would have likely found the term an appropriate description of his “cogs and wheels.” Literally, biodiversity is the many different kinds ( diversity ) of life ( bio- ). Biologists, however, always alert to levels of organization, have identified three measures of life’s variation. Species diversity best fits the literal : the number of different species (see the concept on Evolution of Populations) in a particular ecosystem or on Earth ( Figure ). A second measure recognizes variation within a species: differences among individuals or populations make up genetic diversity . Finally, as Leopold clearly understood, the “cogs and wheels” include not only life but also the land (and sea and air) which supports life. Ecosystem diversity describes the many types of functional units formed by living communities interacting with their environments.
    ::尽管生物多样性的概念直到1948年Aldo Leopold死亡近40年后才成为生物学和政治科学的重要组成部分,但利奥波德 — — 通常被视为现代生态之父 — — 很可能发现这一术语是对其“科学与轮子”的恰当描述。 从字面上看,生物多样性是生命的多种(生物多样性 ) ( 生物 ) 。 然而,生物学家总是对组织水平保持警觉,已经确定了三种衡量生命变化的尺度。 物种多样性最符合字面意思:特定生态系统或地球上的不同物种的数量(见人口演变概念 ) 。 第二项措施承认物种内部的差异:个人或人口的差异构成基因多样性。 最后,正如利奥波德所清楚理解的那样,“科学与轮子”不仅包括生命,还包括支持生命的陆地(以及海洋和空气 ) 。 生态系统多样性描述了与环境互动生活的社区形成的多种功能单位。

    Although all three levels of diversity are important, the term biodiversity usually refers to species diversity. How many species do you think exist on Earth? What groups of species do you think are most abundant? Consider your own experience, and your study of biology up to this point. Think carefully, and write down your answer or exchange ideas with a classmate before you read further.
    ::尽管所有三个层次的多样性都很重要,但生物多样性一词通常是指物种的多样性。 你认为地球上有多少物种? 你认为哪些种类的物种最丰富? 想想你自己的经验和对生物学的研究,直到现在。仔细想想,写下答案或与同学交流想法,然后再阅读。

    What is the Species Diversity of Earth?
    ::什么是地球物种多样性?

    There are three good answers to this question. As a member of one of Earth’s most intriguing species, you should know them all!
    ::这个问题有三个很好的答案。 作为地球上最有趣的物种之一的成员,你应该了解他们!

    1) Scientists have identified about 1.8-1.9 million species. ( Figure  )
    ::1) 科学家查明了大约180万至190万种物种。 (图 )

    Species diversity
    Known species represent only a fraction of all species that exist on Earth.

    The relative numbers of species in each of the six kingdoms of life is shown in the Figure  . The Animal (dominated by the , as shown in the Figure   ) includes the great majority of known species, and , by far the fewest. Most scientists agree that Eubacteria and Archaea are seriously underrepresented, due to their small size and chemistry-based diversity. This leads to a second, and perhaps better answer to our question:
    ::6个生命王国中每个王国的物种相对数量在图中显示了。动物(如图所示,以动物为主)包括了绝大多数已知物种,而且迄今为止也是最少数的物种。大多数科学家都认为,由于Eubacteria和Archaea的体积小和化学多样性,它们的代表性严重不足。这导致第二个问题,也许更能回答我们的问题:

    2) No One Knows How Many Species Currently Live on Earth!
    ::2) 没有人知道地球上目前有多少物种存在!

    Does this lack of knowledge surprise you? Scientists are still discovering new species - not only microorganisms but also plants, animals, and fungi. At least 5 new species of , 25 , 3 rabbits, 22 rodents , 30 bats, 4 whales or dolphins, a leopard, and a sloth were identified between 2000 and 2007 – and these include only mammals! The vast majority of Eubacteria, Archaea, Protist, and even Insect species may be yet unknown because their small size, remote habitats , and the chemical distinctions between species make them so difficult to detect. These challenges, however, have not prevented scientists from estimating Earth’s biodiversity – bringing us to the third answer to our question:
    ::科学家们仍然在发现新的物种 — — 不仅是微生物,还有植物、动物和真菌。 至少有5种新物种 — — 包括25、3只兔子、22只老鼠、30只蝙蝠、4只鲸鱼或海豚、4只豹和1只树懒 — — 在2000至2007年间被确定为 — — 并且只包括哺乳动物。 绝大多数尤伯克西、Archaea、Protic、甚至昆虫物种可能还不知道,因为它们体积小,栖息地偏远,物种之间的化学区别使得它们很难被发现。 然而,这些挑战并没有阻止科学家估计地球的生物多样性 — — 给我们的问题的第三个答案是:

    3) Scientists Estimate that Between 5 and 30 Million Species Inhabit the Earth.
    ::3) 科学家估计,500万至3000万种物种居住在地球。

    Estimates vary widely – from 2 million to 117.7 million, underlining our lack of knowledge. Most estimates fall between 5 and 30 million. Much remains to be learned about the diversity of microorganisms. For example, scientists have recently discovered that Archaea – originally considered limited to extreme environments - may constitute as much as 40% of the ocean’s microbial biomass . Few species have been identified. Estimates of global diversity of the better-studied Eubacteria vary from millions to billions, with orders of magnitude of error. As for , the most “species-dense” ecosystems, such as coral reefs and rain forests, harbor most of the undiscovered species (the Figure  ). Ironically, these ecosystems are also disappearing quickly. In summary, our estimates of biodiversity remain crude. However, the following conclusion is clear: given the current rapid loss of species, we will never know many of the species we are losing.
    ::估计值差异很大 — — 从200万到11.177亿不等,这突显了我们缺乏知识。 多数估计值都在500万到3000万之间。 关于微生物的多样性,还有很多事情还有待了解。 比如,科学家们最近发现Archaea — — 最初被认为仅限于极端环境 — — 可能占海洋微生物生物量的40%。 很少有物种被确定出来。 研究得较好的厄巴克人种的全球多样性估计值从数百万到数十亿不等,误差程度不一而足。 至于珊瑚礁和雨林等最“物种密集”的生态系统,也就是栖息着大部分未发现物种的物种(图 ) 。 具有讽刺意味的是,这些生态系统也正在迅速消失。 总之,我们对生物多样性的估计仍然很粗糙。 然而,以下结论是明确的:鉴于目前物种的迅速损失,我们永远不会知道我们所损失的许多物种。

    Coral reefs (above) and tropical rain forests (below) have the greatest biodiversity of the many ecosystems on earth. They are also among the most threatened habitats. Because our knowledge of their species is incomplete, we are clearly losing species we do not (and never will) know.

    Biodiversity Patterns in Space
    ::空间生物多样性模式

    Are Earth’s 1.8 million known species evenly distributed across its surface? You may already be aware that the answer is a resounding “No!” We will compare two regions with relatively high diversity to begin our analysis.
    ::地球上已知的180万物种是否分布均匀地分布在地表上? 你可能已经意识到答案是响亮的“不 ! ” 我们将比较两个相对高度多样性的区域,开始我们的分析。

    Minnesota has relatively high ecosystem diversity, because three of the Earth’s six major terrestrial biomes converge in this state (Prairie, Deciduous Forest, and Coniferous Forest). By contrast, Costa Rica comprises almost entirely of Tropical Rain Forest, and has only one quarter of the land area of Minnesota ( Figure  ).
    ::明尼苏达州生态系统多样性相对较高,因为地球六大陆地生物群落中有三个(草原、低度森林和隐性森林 ) 。 相反,哥斯达黎加几乎完全由热带雨林组成,仅占明尼苏达州陆地面积的四分之一(图 ) 。

    The state of Minnesota (left) includes three major biomes and four times the land area of the country of Costa Rica (right), which is predominately a tropical rainforest. Figure compares the biodiversity of Minnesota to that of Costa Rica.

    You might expect, then, that Minnesota would have a higher species diversity. Several groups of organisms are compared in the Figure  . Note that a column is included for you to research your own state or region!
    ::您可能会期望明尼苏达的物种多样性会更高。 图中比较了几组生物。 请注意, 包含一栏供您研究您自己的状态或区域 !

    A comparison of species diversity within categories supports the increase in diversity from the poles to the equators. Costa Rica’s increased diversity is due in part to greatly increased niches: diversity begets diversity! For example, poison dart frogs mature in tiny epiphyte pools, and strangler figs climb existing trees and “starve” their hosts of sunlight. Does your state or region support this overall spatial pattern of biodiversity?

    Clearly, biodiversity is much higher in Costa Rica than in Minnesota. Collecting leaves for your biology class in Costa Rica, you would need to study 2,500 different trees in order to identify the species! And you’d need to look carefully to distinguish tree leaves from those of the many (plants which grow on top of others), vines, and strangler figs which climb the trunks and branches, “cheating” their way to the sunlight at the top of the canopy. In Minnesota, keys to native trees include just 42 species of conifers and deciduous broadleaved species. There, vines are relatively rare, and epiphytes are limited to colorful lichens.
    ::显然,哥斯达黎加的生物多样性比明尼苏达的生物多样性要高得多。 在哥斯达黎加,你需要研究2,500棵不同的树以辨别物种。 而且你需要仔细观察树叶与许多树叶(在树上生长的植物)、葡萄树和扼杀的无花果的区别,这些树叶爬上树干和树枝,“切除”树枝顶部的阳光。 在明尼苏达,本地树的钥匙包括42种锥形动物和衰落的阔叶物种。 那里的藤叶相对稀有,附植物局限于有色。

    The differences in biodiversity between Minnesota and Costa Rica are part of a general worldwide pattern: biodiversity is richest at the equators, but decreases toward the poles. Temperature is undoubtedly a major factor, with warmer, equatorial regions allowing year-round growth in contrast to seasonal limitations nearer the poles.
    ::明尼苏达州和哥斯达黎加之间的生物多样性差异是全球通用模式的一部分:生物多样性在赤道地区最丰富,但向极的偏向却在下降。 温度无疑是一个主要因素,较温暖的赤道地区允许全年增长,而北极附近则有季节性限制。

    Generally, the more species, the more niches – so diversity begets diversity.
    ::一般说来,物种越多,位置越多,因此多样性就会产生多样性。

    Does your country, state or region fit the general pattern of decreasing biodiversity from equator to poles?
    ::贵国、国家或区域是否符合从赤道到极的生物多样性不断减少的一般模式?

    Biodiversity Patterns in Time
    ::时间中的生物多样性模式

    How has Earth’s biodiversity changed across time? The is our window into this pattern, although the window has limitations. Microorganisms are poorly preserved and distinguished only with difficulty; gene sequence studies of living bacteria have begun to fill in some missing data. For all organisms, recent rock layers are more accessible and better preserved than ancient ones.
    ::地球的生物多样性在时间上是如何变化的?这是我们进入这个模式的窗口,尽管这个窗口是有局限性的。 微生物的保存不力,其特性只有困难;对活细菌的基因序列研究已经开始填补一些缺失的数据。 对于所有生物来说,最近的岩石层比古代生物更容易接触,保存得更好。

    Despite these drawbacks, and gene studies show a distinct pattern of increasing biodiversity through time. As discussed in the concepts, the origin of life is not clearly understood; evidence suggests that life did not appear on Earth until perhaps 4 billion years ago. For several billion years, unicellular organisms were the only form of life. During that time, biodiversity clearly increased, as Eubacteria and Archaea emerged from a common ancestor some 3 billion years ago, and Eukaryotes emerged by endosymbiosis about 2 billion years ago. However, we have not accurately measured the diversity of even today’s microorganisms, so we have little understanding of changes in the diversity of microorganisms beyond these major events.
    ::尽管存在这些缺陷,基因研究也显示了随着时间的推移不断增加生物多样性的明显模式。 正如在概念中所讨论的,生命的起源并没有被明确理解;证据表明生命直到大约40亿年前才出现在地球上。 数十亿年来,非冰原生物是生命的唯一形式。 在此期间,生物多样性明显增加,因为Eubacteria和Archaea在大约30亿年前从一个共同的祖先诞生,而Eukaryotes则在大约20亿年前通过内生生物学出现。 然而,我们甚至没有准确测量今天微生物的多样性,因此我们对这些重大事件之外微生物多样性的变化知之甚少。

    The emergence of multicellular life about 1 billion years ago certainly increased biodiversity, although we have little way of knowing whether it might have negatively affected the diversity of microorganisms. Fossils remain relatively rare until the famed Cambrian explosion 542 million years ago. Since then, a much more detailed fossil record ( Figure ) shows a pattern of increasing biodiversity marked by major extinctions.
    ::大约10亿年前多细胞生命的出现无疑增加了生物多样性,尽管我们几乎不知道它是否会对微生物的多样性产生负面影响。 直到5.42亿年前著名的Cambrian爆炸发生之前,化石仍然相对少见。 从那时以来,更为详细的化石记录(Figure)显示了生物多样性增加的格局,其特征是大规模灭绝。

    The fossil record for marine species over the past 542 million years shows a gradual increase in biodiversity interrupted by five major extinctions. Some scientists view the recent rapid rise in diversity as a result of better preservation of more recent rock layers and fossils.

    The dramatic increase indicated for the last 200 million years is somewhat disputed. Some scientists believe it is a real increase in diversity due to expanding numbers of niches – diversity begets diversity, again. Others believe it is a product of sampling bias, due to better preservation of more recent fossils and rock layers. Most scientists accept the general pattern of increasing diversity through time, interpreting the magnificent biodiversity of life on Earth today as the result of billions of years of evolution.
    ::过去两亿年的急剧增长有些争议。 一些科学家认为这是多样性的真正增长,因为位子数量不断扩大 — — 多样性导致多样性。 其他人则认为这是抽样偏差的产物,因为最近更近的化石和岩石层得到了更好的保护。 大多数科学家接受随着时间的推移不断增加多样性的普遍模式,在数十亿年的进化中解释了当今地球上生命的巨大生物多样性。

    Most scientists also accept at least the five major shown in Figure , and some hold that regular cycles govern extinction. Causes for these extinctions (more completely discussed in the History of Life chapter) remain incompletely understood; hypotheses include global climate change, major volcanic and continental drift events, dramatic oceanic change, and/or extraterrestrial impact or supernova events.
    ::大多数科学家也至少接受图中显示的五大主题,有些人认为,经常周期的周期会决定灭绝。 这些灭绝的原因(在生命史一章中更全面地讨论)仍然不完全理解;假设包括全球气候变化、重大的火山和大陆漂流事件、巨大的海洋变化和(或)外星影响或超新星事件。

    Increasingly accepted is a current Sixth or Holocene Extinction event. According to a 1998 survey by the American Museum of Natural History, more than 70% of biologists consider the present era to be a sixth mass extinction event - perhaps one of the fastest ever. We will explore the Sixth, or Holocene, Extinction in an additional concept.
    ::根据美国自然历史博物馆1998年的调查,超过70%的生物学家认为当今时代是第六大大规模灭绝事件 — — 也许是史上最快的一次。 我们将从另一个概念中探索第六大或全新灭绝。

    The Current Loss of Biodiversity
    ::目前生物多样性的丧失

    “For one species to mourn the death of another is a new thing under the sun.” -Aldo Leopold A Sand County Almanac, 1949
    ::“一个物种哀悼另一个物种的死亡是太阳下的新事物。”

    Over 99% of all species that have ever lived on Earth are extinct. During the 5 major extinctions recorded in the Phanerozoic fossil record ( Figure ), more than 50% of animals disappeared. Evidently, extinction is natural. However, current extinctions may differ significantly in rate and cause. The IUCN (International Union of Concerned Scientists) has documented 758 extinctions since 1500 CE; for example, 6 species of giant, flightless Moa ( Figure  ) disappeared from New Zealand shortly after the arrival of Polynesians. Estimates of extinctions for the last century range from 20,000 to 2,000,000 species; as for diversity, we simply do not know the true figure.
    ::在Phanerozoic化石记录(Figure)记录的五大灭绝中,超过50%的动物失踪。很显然,灭绝是自然的。然而,目前的灭绝速度和原因可能大不相同。自然保护联盟(国际关注科学家联盟)记录了自1500世纪以来的758个物种灭绝;例如,在波利尼西亚人抵达后不久,6种无飞行能力的巨型莫阿(Figure)物种从新西兰消失。上个世纪的灭绝估计值从20,000到2,000,000种物种不等;关于多样性,我们根本不知道真实数字。

    A gallery of species which have succumbed to the Sixth Extinction: A: one of six species of Moa birds which disappeared after Polynesians first arrived and began to hunt and clear forests in New Zealand about 1500 CE. B: reconstruction of a woolly mammoth, one of many large mammals which became extinct at the end of the last Ice Age, due to human hunting, disease, and/or climate change. C: a reconstruction of the meter-tall flightless Dodo, which disappeared within a hundred years of its discovery, probably due to forest destruction and introduced predators. D: the Golden Toad recently discovered in 1966, has been officially extinct since 1989. Amphibians as a group have declined sharply throughout the world during the past three decades.

    Many scientists begin the Sixth Extinction with the Ice Age loss of large mammals and - part of a continuum of extinctions between 13,000 years ago and now. During that time, 33 of 45 genera of large mammals became extinct in North America, 46 of 58 in South America, and 15 of 16 in Australia. Climate change and/or human “overkill” are hypothetical causes. Supporting the significance of the “sudden” arrival of humans are the low numbers in Europe and South Africa, where humans had coevolved with large animals. The woolly mammoth ( Figure   ) is one of the many examples of large mammal extinctions from this period.
    ::许多科学家在第六次灭绝之初就出现了大型哺乳动物的“冰河时代”消失,这是13 000年前和现在一系列灭绝现象的一部分。 在此期间,45个大型哺乳动物基因组中的33个在北美灭绝,58个在南美洲灭绝,58个在南美洲灭绝,16个在澳大利亚灭绝,15个在澳大利亚灭绝。 气候变化和(或)人类“过度死亡”是假设的原因。 支持人类“突然”到达的意义的是欧洲和南非的低数量,在那里,人类与大型动物相融合。 毛毛长毛巨人(Figure ) 是这一时期大规模哺乳动物灭绝的众多例子之一。

    The first species to become extinct during recorded human history was the Dodo ( Figure   ), a flightless bird which had evolved without predators on an island in the Indian Ocean. Described in 1581, the fearless Dodo experienced hunting, forest , and introduced predators, and became extinct before 1700 – a story repeated for many more species over the following three centuries. Unfortunately, the story extends back in time, as well; over the past 1100 years, human activity has led to the extinction of as many as 20% of all bird species… a tragic loss of biodiversity.
    ::在人类历史记录中,第一个灭绝的物种是Dodo(Figure ) , 这是一种没有飞翔的鸟类,在印度洋的一个岛屿上没有食肉动物的进化。 1581年,无畏的Dodo经历了狩猎、森林和引入掠食动物,并在1700年之前灭绝 — — 在随后的三个世纪里,更多的物种都重复了这一故事。 不幸的是,这个故事又回到了过去的时间里;在过去的1100年里,人类活动导致多达20%的鸟类物种灭绝... 生物多样性的悲剧性丧失。

    Harvard Biologist E.O. Wilson estimated in 1993 that the planet was losing 30,000 species per year - around three species per hour. In 2002, he predicted that if current rates continue, 50% of today’s plant and animal species will be extinct within the current century – compared to hundreds of thousands or even millions of years for pre-human mass extinctions. A dramatic global decline in populations in less than 30 years headlines the recent rise in extinction. Herpetologists report that as many as 170 species have become extinct within that time, and at least one-third of remaining species are threatened. Costa Rica’s Golden Toad ( Figure   ), first described in 1966, was last seen in 1989 and has become a poster species for amphibian declines.
    ::哈佛生物学家威尔逊(E.O. 威尔逊)在1993年估计地球每年损失30,000种物种 — — 约为每小时3种。 2002年,他预测,如果目前的速度继续下去,今天50 % 的动植物物种将在本世纪内灭绝 — — 与人类大规模灭绝之前的数十万甚至数百万年相比。 不到30年的全球人口急剧下降是最近灭绝的头条新闻。 牧民报告说,当时多达170种物种已经灭绝,至少三分之一的剩余物种受到威胁。 1966年首次描述的哥斯达黎加金拖达(Figure ) ( Golden Toad ) ( Figure ) ( Figure ) ( Figure ) ( Figure ) ( Figure ) ( Figure ) ( Figore ) ) ( Figure ) ( Figore ) ( Figure ) ) ( Figre ) ) , 最后一次出现在1989年成为两栖生物衰落的海报物种。

    Summary
    ::摘要

    • Like all species, humans depend on land, water, air, and living resources for food, energy, clothing, and ecosystem services such as nutrient recycling, waste disposal, and renewal of soil, freshwater, and clean air.
      ::与所有物种一样,人类依赖土地、水、空气和生物资源来获取粮食、能源、衣着和生态系统服务,如营养回收、废物处理、土壤、淡水和清洁空气的更新。
    • Unlike other species, human technology supplements “natural” energy resources with fossil fuels and exploits both biotic and abiotic resources and produces wastes beyond the biosphere’s capacity for renewal.
      ::与其他物种不同,人类技术以化石燃料补充 " 自然 " 能源,开发生物和非生物资源,产生超出生物圈更新能力的废物。
    • Biodiversity encompasses all variation in living systems, including genetic, species, and ecosystem diversity.
      ::生物多样性涵盖生活系统的所有差异,包括遗传、物种和生态系统多样性。
    • Scientists do not know how many species currently inhabit the Earth; the vast majority of Bacteria and Archaea, Protists and Insects, are probably unknown. We discover new species of animals, plants, and fungi each year.
      ::科学家不知道目前地球上有多少物种;绝大多数细菌和Archaea、Protisists和昆虫可能并不为人所知。 我们每年发现新的动物、植物和真菌物种。
    • About 1.8 million species have been identified, and most estimates of Earth’s overall species biodiversity fall between 5 and 30 million.
      ::已经确定了大约180万种物种,对地球总物种生物多样性的估计大多在500万至3 000万之间。
    • In general, biodiversity is highest near the equator, and decreases toward the poles.
      ::一般来说,生物多样性在赤道附近最高,流向极地的生物多样性减少。
    • Biodiversity “hotspots” such as the California Floristic Province and unique habitats such as bogs occasionally disrupt the overall pattern.
      ::加利福尼亚佛罗伦萨州等生物多样性“热点”和沼泽等独特生境有时会扰乱总体格局。
    • The fossil record and DNA analysis reveal a gradual increase in Earth’s biodiversity after the first prokaryotes appeared roughly 4 billion years ago.
      ::化石记录和DNA分析显示,在大约40亿年前出现第一批原虫之后,地球生物多样性逐渐增加。
    • Within the past 600 million years, a more detailed fossil record shows increasing biodiversity interrupted by five major extinctions in which at least 50% of species disappeared.
      ::在过去6亿年中,一个更详细的化石记录显示,生物多样性不断增强,但因5次重大灭绝而中断,至少有50%的物种消失。
    • According to a 1998 survey by the American Museum of Natural History, more than 70% of biologists consider the present era to be a sixth mass extinction event.
      ::根据美国自然历史博物馆1998年的一项调查,70%以上的生物学家认为当今时代是第六次大规模灭绝事件。
    • Many scientists regard the Ice Age extinctions of large birds and mammals as the beginning of a continuum of extinctions caused by human activity which extends to the present.
      ::许多科学家认为,大型鸟类和哺乳动物的冰河时代灭绝是人类活动造成持续灭绝的开始,这种灭绝延续至今。
    • Dramatic losses of large mammal species follow a pattern of human dispersal across the globe from tens of thousands of years ago in Indonesia to just over 1,000 years ago in New Zealand, and over 20% of all bird species have become extinct within the past 1,100 years.
      ::大型哺乳动物物种的惨重损失遵循人类散布全球的模式,从几万年前在印度尼西亚的数以万计,到一千多年前在新西兰的1 000多年前,所有鸟类物种中有20%以上在过去的1 100年中灭绝了。
    • Rates of extinction have accelerated in the past 50 years; current estimates include 3 species per hour and as many as 140,000 per year.
      ::过去50年来,灭绝速度加快;目前的估计包括每小时3种物种,每年多达140 000种。
    • In 2002, Harvard biologist E.O. Wilson predicted that if current rates of extinction continue, 50% of plant and animal species will be lost within the next 100 years – compared to hundreds of thousands or even millions of years for previous mass extinctions.
      ::2002年,哈佛生物学家E.O.Wilson预测,如果目前的灭绝速度继续下去,50%的动植物物种将在未来100年内消失 — — 而此前的大规模灭绝是数十万甚至几百万年。

    Review
    ::回顾

    1. Compare humans to other species in terms of resource needs and use, and ecosystem service benefits and effects.
      ::就资源需要和使用以及生态系统服务惠益和影响而言,将人类与其他物种进行比较。
    2. Define biodiversity and explain its three major components.
      ::界定生物多样性并解释其三个主要组成部分。
    3. Give the quantitative values for Earth’s species diversity, and compare biodiversity across the Earth’s surface.
      ::给出地球物种多样性的数量值,并比较地球表面的生物多样性。
    4. What is the sixth mass extinction? What has caused this extinction?
      ::第六次大规模灭绝是什么?