Issue121【Triple Week】第1次练习by完美飞行家

完美飞行家UID: 2622083

Species extinction ,as it seems ,is a result of natural selection.It might begin just after the species origination. No wonder, somebody would argue that there is no justification for society to make extraordinary efforts ,especially at a great cost in money and jobs to save endangered species.But as we look into this problem seriously,we may find that today’s extinctions of  plants and animals are somewhat unnatural.

Accoding to a recent survey :”the earth is losing approximately 27000 species per year,translating into astounding 3 species per hour”.This extraordinary rate of extinction has ever occurred five times before in history of complex life on Earth,well known as Mass extinction.The latest one ,which occurred more than 65 million years ago,resulted in the demise of 76 percent of all species alive at that time,including the famous dinosaurs.And now, we are in the period of the six Mass Extinction just like that.

When dicussing the causesof extinction,it is hard to say why the species on today’s earth turn to disappear so fast and exactly,what kind of role the human being has played in this process.But as we know what is no doubt is that human being has accelerate the extinctions of plant and animals .There are many reasons why a particular species may become endangered. Although these factors can be analyzed and grouped, there are many causes that appear repeatedly. Below are several factors leading to endangerment:habitat distruction ,environmental pollution,introduction of exotic species by human being,overexploitation to the nature,etc.All of this factor done by human greatly contributed to the species endangerment and extinction .

We human being and other species live on the same planet and the earth is a large ecosystem as a whole.It’s difficult tell exactly how species diversity affect the human being but we do know it’s of great importance to the living condition to us.We can benefit from species diversity in many ways.

In the first place,protecting the species which is endangered is to protect the balance of the ecosystem.Healthy ecosystems are vital to life,and in turn,the health of ecosystems depend on the continued health and vitality of the individual organisms that composed them.Removing just one species from an ecosystem could damage,even destroy it. For instance, in the late 19th and early 20th centuries, sea otters were hunted to near extinction in many kelp forests off the coast of the Pacific Northwest of the United States and western Canada, causing the entire ecosystem to suffer. Otters eat sea urchins, and when the otters disappeared, the sea urchin population exploded and started to destroy the vast beds of kelp. Without the kelp, other species that lived in the ecosystem, including many species of fish and snails and other invertebrates, began to decline in number. Such subtle relationship between species is always difficult to explore, rendering the effect of species extinction unpredictable and far-reaching. Maybe one day, our offspring find it is our mistake that lead the ruin of human life.

In the second place,even if the condition is not as serious as extinction, the protection of biodiversity is still benefit human beings immensely. Scientists have discovered and named only 1.75 million species—less than 20 percent of those estimated to exist. Each of these organisms has unique attributes, some of which may hold the secrets to increase world food supplies, eradicating curing disease. A subspecies of the endangered chimpanzee, for example, has recently been identified as the probable origin of the human immunodeficiency virus, which causes acquired immunodeficiency syndrome (AIDS). But these animals are widely hunted in their west African habitat, and just as researchers learn of their significance to the AIDS epidemic, the animals face extinction. If they become extinct, they will take with them many of the secrets surrounding this devastating disease. Fortunately, these chimpanzee has been preserved, but other three species thoroughly disappeared while I finished this issue, and we even do not know who they are.

In sum,a heathy ecosystem is essential to the human bing,protecting other species living on this planet is to protect our living condition on the other side.If we continue to be indifferent to this issue and do nothing to save the species which is endangered,the next specie to be in endangerment may be ourselves.

newletter2002UID: 2653136

Species extinction ,as it seems ,is a result of natural selection.It might begin just after the species origination. No wonder, somebody would argue that there is no justification for society to make extraordinary efforts ,especially at a great cost in money and jobs to save endangered species.But as we look into this problem seriously,we may find that today’s extinctions of  plants and animals are somewhat unnatural.

Accoding to a recent survey :”the earth is losing approximately 27000 species per year,translating into astounding 3 species per hour”.(运用统计数据来说明自己的观点，值得借鉴)This extraordinary rate of extinction has ever occurred five times before in history of complex life on Earth,well known as Mass extinction.The latest one ,which occurred more than 65 million years ago,resulted in the demise of 76 percent of all species alive at that time,including the famous dinosaurs.And now, we are in the period of the six Mass Extinction just like that.

When dicussing the causes
of extinction,it is hard to say why the species on today’s earth turn to disappear so fast and exactly,what kind of role the human being has played in this process.But as we know what is no doubt is that human being has accelerate the extinctions of plant and animals .There are many reasons why a particular species may become endangered. Although these factors can be analyzed and grouped, there are many causes that appear repeatedly. Below are several factors leading to endangerment:habitat distruction ,environmental pollution,introduction of exotic species by human being,overexploitation to the nature,etc.All of this factor done by human greatly contributed to the species endangerment and extinction .

We human being and other species live on the same planet and the earth is a large ecosystem as a whole.It’s difficult tell exactly how species diversity affect the human being but we do know it’s of great importance to the living condition to us.We can benefit from species diversity in many ways.

In the first place,protecting the species which is endangered is to protect the balance of the ecosystem.Healthy ecosystems are vital to life,and in turn,the health of ecosystems depend on the continued health and vitality of the individual organisms that composed them.Removing just one species from an ecosystem could damage,even destroy it. For instance, in the late 19th and early 20th centuries, sea otters were hunted to near extinction in many kelp forests off the coast of the Pacific Northwest of the United States and western Canada, causing the entire ecosystem to suffer. Otters eat sea urchins, and when the otters disappeared, the sea urchin population exploded and started to destroy the vast beds of kelp. Without the kelp, other species that lived in the ecosystem, including many species of fish and snails and other invertebrates, began to decline in number. Such subtle relationship between species is always difficult to explore, rendering the effect of species extinction unpredictable and far-reaching. Maybe one day, our offspring find it is our mistake that lead the ruin of human life.

In the second place,even if the condition is not as serious as extinction, the protection of biodiversity is still benefit human beings immensely. Scientists have discovered and named only 1.75 million species—less than 20 percent of those estimated to exist. Each of these organisms has unique attributes, some of which may hold the secrets to increase world food supplies, eradicating curing disease. A subspecies of the endangered chimpanzee, for example, has recently been identified as the probable origin of the human immunodeficiency virus, which causes acquired immunodeficiency syndrome (AIDS). But these animals are widely hunted in their west African habitat, and just as researchers learn of their significance to the AIDS epidemic, the animals face extinction. If they become extinct, they will take with them many of the secrets surrounding this devastating disease. Fortunately, these chimpanzee has been preserved, but other three species thoroughly disappeared while I finished this issue, and we even do not know who they are.

In sum,a heathy ecosystem is essential to the human bing,protecting other species living on this planet is to protect our living condition on the other side.If we continue to be indifferent to this issue and do nothing to save the species which is endangered,the next specie to be in endangerment may be ourselves.
这篇文章我觉得是一篇很值得我学习的文章。语言和用词都比较讲究和优美。文章的结构虽然没有模板那么清晰，但是我觉得很有个人风格，很好。