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  • 生物多样性生物多样性生物多样性

    Collage showcasing various species representing biodiversity: mammals, reptiles, fungi, plants, insects, and fish.

    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?

    Biodiversity refers to the variety of life and its processes, including the variety of living organisms , the genetic differences among them, and the communities and in which they occur. As of the year 2021, scientists have estimated nearly 2 million species or more have been identified. New species are constantly being discovered, while some already-known species get reclassified by scientists, a practice that has become more common as sequencing has become more accessible for researchers. They are divided into the six kingdoms of life shown in the table  . It is unclear how many species exist on our planet, but estimates as high as 100 million or as low as 3 million have been justified by scientists.
    ::生物多样性是指生物的多样性及其过程,包括生物机体的多样性、生物机体之间的遗传差异、生物群落和发生生物体的过程。截至2021年,科学家们估计已发现近200万种物种或更多物种。新的物种不断被发现,而一些已知物种被科学家重新分类,随着研究人员更容易获得测序,这种做法变得更加常见。它们被划分为表所示的六个生命王国。不清楚我们星球上有多少物种存在,但科学家们认为,估计高达1亿或不到300万物种是合理的。

    Biomass Distribution of Life on Earth

    Mass (Gtc, Gigatons of carbon)
    ::质量 (Gtc, 千兆吨碳)

    1 Gtc = 1,000,000,000 tons of carbon
    ::1 Gtc = 1 000 000 000 000吨碳

    		% of total mass
    7 1.3%
    Bacteria 70 12.8%
    0.2 0.04%
    Plants 450 82.4%
    Protists 4 0.70%
    Fungi 12 2.2%
    2.589 0.47%
    Total 545.8 100.0%
    Information taken from

     

    Cogs and Wheels
    ::眼镜和轮轮

    “To save every cog and wheel is the first precaution of intelligent tinkering.” - Aldo Leopold, Round River: from the Journals of Aldo Leopold , 1953
    ::“拯救每一个齿轮和轮轮是智能修补的第一预防措施。”

    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 translation: the number of different species in a particular ecosystem or on Earth. A second measure recognizes variation within a species: differences among individuals or make up genetic diversity . Finally, as Leopold clearly understood, the “cogs and wheels” include not only life but also the land, sea, and air that support life. Ecosystem diversity describes the many types of functional units formed by living communities interacting with their environments. Although all three levels of diversity are important, the term biodiversity usually refers to species diversity.
    ::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 — — 通常被认为是现代生态之父 — — 很可能发现这一术语是对其“科学与轮子”的恰当描述。 诚然,生物多样性是生命(生物-)的多种(多样性 ) 。 然而,生物学家总是对组织水平保持警觉,确定了三种衡量生命变化的尺度。 物种多样性最符合字面解释:特定生态系统或地球上不同物种的数量。 第二项措施承认物种内部的差异:个人之间的差异或构成遗传多样性。 最后,正如利奥波德所明确理解的那样,“科学与轮子”不仅包括生命,还包括支持生命的陆地、海洋和空气。生态系统多样性描述了与环境互动的活体社区组成的多种功能单位。 尽管所有三种多样性都很重要,但生物多样性一词通常指物种多样性。

    Science Friday : The Unlikely Tale of a Tenacious Snail
    ::科学周五: 坚固的斯奈尔的奇谈奇论

    For over 70 years, no one had seen the oblong rock snail. Declared extinct in 2000, the species was considered to be another native Alabaman mollusk gone and forgotten. But one day in the spring of 2011, biology grad student Nathan Whelan picked up a tiny rock and got a big surprise.
    ::70多年来,没有人见过这只孤注一掷的岩石蜗牛。 2000年,该物种被宣布绝种。 2000年,该物种被认为是另一个亚拉巴马土著软体动物被遗忘的原生。 但2011年春天有一天,生物学研究生内森·惠兰(Nathan Whelan)捡起一块小石头,大吃一惊。

    Further Reading 
    ::继续阅读

    Summary
    ::摘要

    • Biodiversity refers to the number of species in an ecosystem or the biosphere as a whole.
      ::生物多样性是指生态系统或整个生物圈中的物种数量。

    Review
    ::回顾

    1. What is biodiversity?
      ::什么是生物多样性?
    2. What are the three measures of life’s variations?
      ::生活变化的三种衡量尺度是什么?
    3. What is meant by ecosystem diversity?
      ::生态系统多样性意味着什么?